E30 M3 minor rust repair (few finished pic's)

[Gortour]

Seconded John, the write-ups are as good as the work...
...and the work is f***ing QUALITY!!!

A fabulous read.

[madaboutthe30]

You know it's all about the engine build...!

I agree, I cant wait for that one

[m42sport]

Someone should send this man a better camera!! awesome work

question, where did you get the stainless steel nuts/bolts?

[bmw_pr]

This is the "TRUE"body rerstauration and indeed bimer love

[doc323]

This is even better than a 4x4 is born on discovery.....seriously this should be on there!!!

Great work!!

[Kedge]

This restoration would probably be more useful to most the Zoners than a Haynes manual, the detail in the post it brilliant!

[retroboyo]

It's been a privilege to read this thread, thank you

[johnt0709]

update??

[xavi1980]

UN FUCKIN REAL!

[johnt0709]

Getting withdrawal symptoms here......

[x-works]

Apologies, should have something up in the next fortnight.
Life has been interfering with the build schedule.
(or to be more accurate, beer)

[Royalratch]

Apologies, should have something up in the next fortnight.
Life has been interfering with the build schedule.
(or to be more accurate, beer)

Cut this life stuff out dude, it's interfering with OUR schedules lol.

[jaistanley]

Excellent work...

BUT I feel I must warn you. I did EXACTLY the same when welding on the camber adjuster tabs to my rear beam, with the thought I'd add an extra bit of adjustment to remove the camber of lowering.

I lined the bottom of the adjuster tab up with the hole, as you did, welded, die grinded, painted, fitted etc etc. Then didn't fit massively low springs (I wanted the car to HANDLE) and took it for alignment. I now have 0.5 degrees of negative camber at the rear when set to maximum camber on the adjusters!!!

Admittedly I had the car aligned exactly the same left and right, with perfect toe, camber on the front and rear and the car drives like no other E30 I've been in. Utterly straight and true, loads of feedback and grip etc etc. Unfortunately the 0.5 degrees of camber at the rear (factory specs is more like 2 degrees!!) means I get quite a lot of lift off oversteer in the wet. To be fair to the old girl she has 320 brake so I generally get quite a lot of oversteer in the wet!

I think I'm going to remedy it by fitting some slightly lower rear springs (which will probably get me to more like 1 - 1.5 degrees) for now but intend to make a new beam with less severe adjustment of rear camber so I can set it exactly to E30 M3 factory specs.

Otherwise, incredible attention to detail.. Loving the car!

Jai

[Royalratch]

How on earth can he ever drive this thing it's just so minty fresh under there lol.

[x-works]

Evenin all,
Been a while since the last update, the reason being I appear to have
well and truly busted something in my back. I'd love to give
you a more accurate diagnosis but unfortunately my doc is a foreign
lad and for the life of me I can't tell what he's saying half the time.
But judging by the serious look on his face and the size of the horse
tranquillizers he's prescribed for me, I'm guessing i'll not be doing
cartwheels any time soon. But as they say, every cloud has a silver
lining and despite the fact you need a knife and fork to take
the pain killers the effects of them are marvellous. I now wear a permanent
"stoner" grin all day long and can walk through brick walls without
so much as an itch.
Anywho, before this post starts to sound more like an bleeding heart
letter we'll move on to what I've managed to mess around with on the
car this time.

First up I need to put my hand up and admit to a co*k up from the last
update. For those who can't remember back that far, I had welded in some
reinforcement bars on the rear wishbone's like so......



Well not long after posting up the pic's and details on the web I got a
heads up from a member on S14.net to say he'd tried the same mod
and ran in to some difficulties upon refitting them. The difficulty?
When the wishbones are refitted, just above them runs the rubber
fuel filler pipe that carries fuel down from the filler flap to the fuel
tank under the car, like so......
(modified tube in purple, red arrow is where the fuel will run into
the tank, when fitted)





Which all looks fine and dandy, until you realise thats with the wishbones
in full droop. As soon as you lower the car back onto the ground the
wishbones go back up towards the floor plan and squash the rubber
filler pipe flat.

fu*k.

Making it impossible to fill the car with fuel.

double fu*k.

So i retired to give the matter some serious thought.......



And then, when all seemed lost, it hit me, I had a brain wave,
a perfect solution to the problem, it was so simple i couldn't
believe I hadn't thought of it earlier .....



cut them out, fu*k them away and move on.

[x-works]

Next up, the alternator.



Or to be more precise, pull it asunder, fiddle about with it and then
try and figure out how it goes back together again.
Starting at the rear end these bits and bobs came off first.....



Number 4, the earth lead. Responsible for earthing the alternator
to the chassis via the engine block......



this needs to be in good condition as you can get all manner of
strange electrical faults if this lead starts to fail due to corrosion of
the terminals or the copper wire inside corroding. As this one was starting
to show its age and the outer insulation was badly cracked, a new one
was made up to replace it......



Number 3, the suppressor. This little dude just bolts on to the back
casing of the alternator and the little wire from it connects to a male
spade terminal which sticks out of the casing. It's purpose is to stop
electrical interference from the voltage being created inside the alternator
from messing with other electrical systems on the car. Like the stereo
buzzing up and down as the engine revs rise and fall. Nothing much to
be done with it, if it works it works. If it doesn't, get a new one.....



Number 2, the wire terminals plastic insulation. There's just two wires
that go to the alternator, a big fat one which is main battery power
and is connected back to the battery positive terminal via the starter
and a little wire which comes from the battery light up on the dash.
Both these wires are live and if they manage to touch off the alternator
casing, which is earthed, you'll get a nice little fireworks display right
before the fire starts. So this little plastic insulator lets the wires bolt
on to the two studs sticking out without touching the casing. To remove
it, the two nuts that hold the wires in place come off and then another
two nuts below this come off to let the insulator slide up and off.......



And finally, number 1. The brush pack and regulator. Undo the two
little screws and it lifts out of the casing. This thing is the most common
reason for alternators failing to charge. An alternator has a shaft rotating
inside it (rotor), and for the alternator to do it's thing
and produce some voltage you've got to pass a current onto this rotor
and then give it a route to get back out again. To do this the
shaft has two brass rings on it, which we'll get to later, and two
little carbon "brushes" (red arrowed below) are pressed against the
brass rings allowing current to pass in through one, do it's job and
then pass out back up through the other. The little brushes seen below,
have little springs underneath them to keep them rubbing against the
rotor all the time as it turns. Eventually the little brushes wear out
and can't reach the slip rings any more and the alternator stops charging.
The other part of this little unit is the little black thing on the front
(blue arrow) which is the voltage regulator, and as the name suggests
it's job is to control the voltage coming out of the alternator. To much
voltage could damage other electrical systems in the car so it drops the
voltage down, to little voltage been produced (headlights, demister,
rear window defogger all on) and it raises back up the voltage. All
the time it's trying to keep the output at roughly 14 volts.



In the pic below you can see that the brushes in my brush pack were
on their last legs and hadn't to long left to go when compared to the
new brush pack next to it......



If your alternator packs in, this is one of the first things worth checking.
A new brush pack is only about 10/15euro from a motor factors.
And once you've the alternator off it's just a matter of undoing the two
little screws and lifting out the brush pack to check the height of the brushes.
There's a few different brush packs fitted to e30 alternators due to
the alternators having different power outputs, so if your going to order
one use the part numbers on the old brush pack to make sure your
new one is a perfect match.
One final little piece of advice, if your changing a brush pack, go softly, the little
carbon brushes are brittle and don't bend, so be gentle sliding it in to
place. Use the force Luke, not the hammer.

With all that stuff stripped from the rear end it was time to flip it over
and start on the front. The centre of the shaft has a hole to accept an
allen key so you can hold the shaft while loosening the front pulley nut.
The pic below shows the order in which the collection of washers come
off. Whats interesting if you've never stripped one before is the alternator
pulley isn't actually a solid pulley, but instead two concave washers
squeezed together......



Once that stuffs off next up is the 4 main bolts that hold the casings
together. Before splitting the casings it can help to make a little mark
or scribe a line on the 3 main bits of the alternator so they can be
bolted back in the same orientation......




Its also worth making a mental note that of the four bolts that hold the
casings together, two are longer than the others. Reason being when
in place these two stick out the back of the alternator casing a little
bit and are used to screw clips onto to secure the wires going to the
alternator. They need to go back in to the same hole on reassembly......



with them 4 bolts out of the way, next up is the 4 inner ones shown below.......



and then with some gentle persuasion (beating and cursing) the front
casing "should" just slide off......



next up, the rear casing and stator (middle bit). Sometimes these will
slide off easily, but as is always the case with this fu*king car, these
were not going to come off without a fight. Shaft gets tightened in the
vise (with soft jaws so as not to mark the shaft).......



and this little dome on top of the rear casing which houses the rear
bearing gets a little heat from the heat gun to expand it and help it
let go of the bearing inside......



and hey presto, off she comes.

[x-works]

Once these two pieces were off they separate fairly handy. Rear casing
on the left, stator and diode pack on the right.....



First item to be changed in here is the diode pack. Old one still
attached, new one below it.....



Without going to deep into the black magic that happens inside an
alternator, the main job of this diode pack is to convert the AC voltage
which the alternator makes, into DC voltage which the car needs.
There, thats as clear as mud isn't it.
AC voltage is the stuff that powers your house, and AC is short
for alternating current, which basically means the little volts travel
backwards and forwards like mini Duracell bunnies on coke.....



and AC voltage is no good for a cars power system which is DC
voltage (direct current), where all the little volts march along in the
one direction nice and calmly. So the diode pack has a little bunch of
diodes in it which are basically one way valves for electricity. They'll let
the voltage through but not go back again. And so convert
the AC back to DC voltage which the car can use.
(If you listen carefully you can actually hear Albert Einstein spinning
in his grave after that explanation).
In the pic below the main roundy bit (the stator) is where the black
magic takes place and the AC voltage is made. And connected to
this by four wires is the diode pack in the middle....



I don't think the diode pack has a certain service life really, theres no
wearable parts in it like the brush pack has. However over time the
diodes can fail and stop the alternator charging and as I'm changing
everything else in here Murphys law states that if I reuse the old one,
it'll fail down the road just to p i s s me off for not changing it while it
was all asunder.
So,
heat up the solder and pop the wires free....



and then solder the wires back in to the new diode pack. Best to
have the soldering gun nice and hot for this, so you can solder each
joint quickly. If too much heat soaks into the diode pack it can fu*k
it up.....





with that done it's on to the rotor, and changing the bearing at either
end of it. The one on the left is a straight forward, old one off, new one
on affair. While the one on the right, the larger of the two is a little more
involved. In front of the bearing theres a fat little shim and behind it
there's a little square plate. The little plate is what the 4 little screws
removed from the outer casing back in the beginning screw into.
And it's purpose is to keep this bearing snug and tight up against the
casing and not wandering up and down the shaft......



The other job that needed doing while the bearings were off was to
change the brass slip rings. As mentioned earlier the two little brushes
in the brush pack rub against these slip rings, and just like the brushes
these rings also wear down over time. You can see in the pic below
the two grooves that have worn down into them. Usually you'll get
through about 2 or 3 sets of brushes before the slips rings need to
be changed and by that stage most cars are at the end of their life.
However, as this car has 24 years under her belt it's not that unusual
that they're this worn......



they're a tricky little fu*ker to change though. In the pic below you
can see two wires coming out of the centre of the rotor and going
into the slip rings where they are soldered on. So the slip rings are
carefully sliced with a small cutting disc on the dremel, on top and
bottom like so........



and then popped apart. The wire on the right (purple) is soldered
to the inner edge of the inner ring and the wire on the left (green)
runs up the inside of the rings before soldering on to the outer edge
of the outer ring.......



With the old rings removed and the wires cleaned up and the shaft
where they sit cleaned up with some emery paper, the new rings
are slid on making sure that the green wire in the pic slides up through
the middle. With everything back in it's rightful place the wire ends
can be soldered back on. The one thing to be careful of is that the
wire insulation is in good condition when doing all this, as if either of
them 2 wires touch any part of the shaft or rotor because of a break
in the insulation then they'll just short out and blow the alternator when
it's refitted......



with the slip rings done the new bearing can be pushed on this end......



and then turned around and plate, new bearing and fat shim fitted to the
other end.....



With all that crap done, it was on to the alternator casing bushes.
Pull them out and check their condition....



circlip and washer off......



and then the insert can push out the opposite side......

[x-works]

and then you can pop the bushes out. To my surprise it seems a previous
owner has fitted polly bushes instead of the original bushes, and they're
still in perfect nick......



From reading on various forums it seems this change from original
rubber bushes to harder polly bushes is to cure an inherent problem
with alternators on the M3's S14 engine. The engine likes to vibrate
a lot especially when your driving arse out of it (as all M3's should be).
And this makes the alternator with the standard bushes vibrate a lot
too, which can snap the adjuster bracket and leave you without a
working alternator. So the polly bushes stiffen things up a bit and
makes life a little easier for the adjuster bracket.
At least thats my understanding of it, no doubt I've probably got it
arseways as usual.

With all the bushes checked and the casings cleaned up it was time to
nail it all back together and hope for once that you don't end up with
bits left over.
First up the 2 little studs that poke through the back of the casing to
attach the power leads to, making sure the little inner plastic insulators
are in place so that the studs can't arc off the casing, spark, fire, boom,
tears.......



pop it into the rear casing......



and pop the outer insulator back on securing it with the two little nuts.
Also the little suppressor dude goes back on......



then the stator (outer bit) and rotor (inner bit) sits down into the casing.
Rotor may need a little tap to get the small bearing the other end of
the shaft back into it's little dome in the casing......





and then finally the front casing pops on (making sure you've aligned the
3 markings you've made on the casings before stripping). Then the
4 main outer bolts are refitted and tightened to hold the casings together
and finally the 4 inner screws that hold that little plate behind the front bearing
tight to the casing are refitted.
When all thats done the brush pack can be slotted back in (softly, softly).....



and the earth lead reconnected........



followed by all the bits that make up the front pulley section......



and voila!.......



After this it was hooked up to our state of the art, mobile, water cooled,
alternator test bed to check it was charging........



engine running and everything electrical turned on and bingo 14 volts
at the battery. Didn't even need to use the fire extinguisher, how
professional is that?



And thats about it for now. Depending on how whacked I get
on pain killers this evening I hope to have the next bit up
tomorrow.
Till then.......

[johnt0709]

Amazing - as usual and with out sounding as though I want to start a Bromance - how can you know so much, seriously is it a lot of googling or just yoda years of experience?

[Nay]

It is officially my mission in life to follow this from start to finish

[Royalratch]

Lol - I'm in for the long haul too. Can see us tuning in a year or two as he tackles the Tire Valve rebuild.

[x-works]

Next up the starter.......



Two main bits to the starter, the big bit on the bottom is the actual
motor that turns the engine over and then the smaller bit on top which
is the solenoid. And it's the solenoid thats first to be removed.
Three screws at the front are undone.....



and on the back end, the nut shown below is undone and the main
power lead to the motor underneath is removed.....



Which leaves the solenoid free to be removed
(don't lose the little spring left behind its important!).....



next up, the two main bolts that hold the motor to it's nose casing......



which allows the nose casing to be removed and reveal the starter
pinion gear (bit with the teeth) and the solenoid linkage......



here's how I "think" it all works. The pic below shows
the terminals of the solenoid which sits on top of the motor.....



The starter takes a fair whack of juice to get it to turn over, and as
such, it needs a fat wire to carry all that power down to it. It doesn't
make sense to run the wire through the ignition switch on it's way to
the starter because you'd need a bloody huge ignition switch on the
steering column to be able to handle that amount of power.
So,
The main feed for the starter (big fat black wire direct from the battery
positive terminal) runs directly to terminal 1 on the starter solenoid shown
above. When you turn the ignition switch to start position, power comes
down a smaller black/yellow wire to terminal 3 and travels across inside the solenoid
to terminal 4 and earths. While travelling across to terminal 4 it energises a little magnetic
coil inside the solenoid, which pulls in a set of contacts, and allows the big power
from terminal 1 to flow over to terminal 2 and start the motor turning.

So with all that done the starter motor is now turning over, the only problem is
the little starter gear (pinion gear) on the front of the starter that engages with the
flywheel ring gear to turn over the engine needs to be pushed forward to reach
the flywheel. (if it was in contact with the flywheel all the time the starter would
sh*t itself as the engine revs started to rise)

So,
the solenoid on top of the starter has another little job to do.
In the pic below the little green metal cylinder on top of the starter
is pulled (magnetically) into the solenoid when you turn the key to the
start position.
And attached to the back of the green cylinder is a little
green linkage with a fork on the bottom end.
The blue part in the middle is fixed and acts as a hinge point for the green linkage.
As the top part is drawn into the solenoid the bottom part (pinion gear)
is pushed outwards and into contact with the flywheel ring gear.
And now the starter is turning the engine.
Thats pretty much what happens when you turn the key,
motor starts tuning and the teeth push out and engage with the flywheel
and crank up the beast.
As soon as you let go the key, the magnetism thats holding the green cylinder
in, is lost, and that little spring shown earlier pushes the cylinder back out,
which in turn pulls the starter teeth back away from the flywheel.



Sometimes if your trying to start a car with a flat battery the engine just
makes a clicking sound but doesn't turn over.
Theres enough power to pull the cylinder into the solenoid and shoot
the pinion gear out to the flywheel (which is the little click you hear)
but not enough power to travel down the fat wires and turn the engine over.

The pic below shows a starter which has been disassembled using the
"f*ck, what did I just drop, I wonder was it important" method.....



and the one below shows a starter which has been reassembled using
the "it'll be a f*cking miracle if this ever works again" method......



last thing to do upon reassembly is bench test it. A set of jump leads,
big power to terminal 1 and the earth lead clamped onto the casing.
Any finally a little piece of wire to give a dart of power to the smaller
terminal 3, which should bring the starter to life. If it doesn't, beat it
to death with and hammer, hide it under the bench, and tell anybody who
asks, "it was to far gone to repair".....

[x-works]

Staying on the theme of motors, next up was the wiper motor and linkage.....



plastic cover pops off to reveal the motor.....



on the other side is the bolts to disconnect the motor from the linkage.
3 red arrowed bolt release the motor body and the purple arrowed nut
releases the linkage from the motor spindle.....



strip of water sealing tape removed......



to reveal the two screws that hold the two halfs of the motor together......
(one this side in pic and one directly opposite the other side)



screws undone and black bit slid off.....



all i'm interested in checking in here is the motors brushes.
There's 3 of them......



You can check the condition of the brushes with just stripping as
far as above, but since I've a mental dysfunction which makes me
want to strip everything down to the last nut and bolt, belows a clearer
picture of the brushes. Theres 3 of them, only two sticking out of their
housings below (red arrows)......



as the third one is the earth brush and is connected to the housing.....



all the brushes still had plenty of life in them so everything gets cleaned
and jumbled back together......



remembering to put some tape around the top part again so
water can creep in and fu*k things up in there.....



after that it was on to the linkage.......



on top of the linkage spindles are a large nut and two washers which
secure the linkage to the scuttle panel on the car, and if yours is out
and on the bench these will already have been removed. Just in the
centre of this though is a little small circlip......



which when undone allows the spindle shafts to slide out of their
housings. Both shaft and housing (purple and red arrows) each side get
cleaned up and greased to help prevent against noisy wipers.....



after which the joints in the linkage are done. These just pry apart,
softly, with a large screwdriver (be careful not to damage the rubber booth).....



when apart they're cleaned and inspected. In one of them the grease had
gone hard and the linkage was just starting to wear a groove in the ball.
The one on the left below is the good one, and on the right you can see
the wear grooves just starting on the ball....



thankfully the ball wasn't badly grooved yet and it cleaned up nice with
some fine sandpaper. When these get badly grooved the wiper linkage starts
to get annoyingly noisy and the wiper blades get sloppy on the windscreen.
With everything cleaned up, they were all reassembled with plenty of fresh
grease and the wiper motor reconnected.......



refitting of wiper linkage to car is an interference fit, for this reason
it is recommended that special tool part number 959sledgehamer
is locked away before undertaking said task.

And thats it for tonight.
Join us again tomorrow night for more cliff hangers,
plot twists and the continuation of the worlds most
monotonous thread
Till then......

[Royalratch]

[johnt0709]

fantastic

[evosport1990]

Just spent the last couple of hours reading this. Top work.

[suchy]

Fantastic....STILL!! Who'd have thought one could be so compelled with an alternator/starter motor/wiper motor rebuild??
Mental!!
I beginning to think this guy may even know more than Mr.Mooooooore.....
Just keep it coming

[johnt0709]

seems inappropriate that their status is e30 zone newbie when they have contributed so much - master technician status or something like that would be more appropriate.......?

[x-works]

Apologies for the delay getting this next part up, I had half of this
waffle typed up and then the interweb broke, or something, and it
all disappeared. It took a little time after that to fetch the computer
from the neighbours front garden and reassemble it all again.
Anywho, back to the story.......

Next to get refitted was the ABS motor, nothing much to do with
this. It was removed from the car in the beginning just as you see
it below. And all of the pipes that had to be disconnected from the unit
on removal had the open ports plugged to stop the fluid draining
out of the motor. These can be a bit of a pig sometimes to bleed
out upon refittal it she's been allowed to completely empty inside.....





Just before fitting it, the little protective cover is popped of the rear end
to check the condition of the electrical connections for all the stuff in there.
The relays are pulled (red arrows) to check for any corrosion on the pins
beneath which may have been caused by dampness getting in.
And the pins sticking up (purple arrow) where the main ABS plug will
fit on are also checked for corrosion. All clear, she was good to go......



after that the brake servo and master cylinder......



two nuts undone from the servo allows the master cylinder to drop off......



servo was looking a little second hand, so she got a sand and lick of paint.....





On to the master cylinder, the little reservoir on top just pulls off
(gently).....





then the two rubber grommets pop out, and you can see the little
slotted washer in the port of the rear chamber.....



washer just lifts out and needs to be remembered upon reassembly.
The purpose of this washer is top secret. I could tell you, but then I'd
have to kill you. (yep, I haven't a clue either)......



The ABS type master cylinder isn't constructed with overhauling in mind,
hence the circlip on the front with no holes to get a circlip pliers into (marked red).
And with the main dealer listing no internal parts and the motor factors drawing a
blank as well, I decided to leave well enough alone. I've no intention of renewing
the cylinder just for the sake of it, they're fairly pricey, and this one is showing no
external signs of failing. If she does down the line, then I'll replace it.

A mod that seems fairly common out there, is to change the master cylinder with
one from a seven series bm, which has a larger internal bore and as such stiffens up the
brake pedal a lot. I've driven an e30 with this mod done, and it ain't for me. The
brake pedal was uncomfortably hard for everyday driving. I could see why you might
do it in a competition car, but a road car, not for me. Each to their own though.

The one thing I did change was the little square sectioned O ring on the snout
of the cylinder (purple arrow).....



after that cylinder took a clean up.....





and everything reassembled. Next up, clutch slave cylinder.....



this is such an easy task with the pedal box out of the car as opposed
to changing one in place. If you'd like a more realistic experience on
how to change a clutch master cylinder in place, then lay crunched up on your
back on the floor, and hold the monitor over your head and swear
repeatedly at it while reading this......



two mounting bolts and one pivot bolt secure the new cylinder in place......



and with that done the ABS unit, brake pipes and master cylinder could
be fitted back in the engine bay......





while the pedal box was rebolted back inside......

[x-works]

Next up, heater motor......



starting up top first with the actual fan motor......



power and earth wire's are disconnected from the motor.....



followed by undoing the four tabs on the front of the fan cowls and
another four on the rear (softly, softly, 20 odd years of living out
under the scuttle panel and they're fairly brittle)......





cowls removed and it's on to pulling the motor out. After 20 minutes
of beating chunks out of it I finally figured out
the motor retaining clip (coloured blue below) is popped free at
the bottom and hinged up......





to allow the motor to lift out.....



first up was to check the motor shaft for any play side to side or
wibbly wobbly (technical term), if there is, dump the motor and get another,
it's not worth the grief trying to change the bearings on these.
With that done the only other thing I wanted to check while it was out
was the motor brushes, which are under these clips......



Two in total, one each side. Clips just pop off ,and the springs underneath
like to head off into the scenery, which turned this particular job into
a frustrating fu*king treasure hunt......



with the clips removed you can see the brushes in their little housing.....



when slid out they were found to be not even half worn yet, so they're
good to go for another long while yet.......



Next up was the little resistor pack, which resides just above the water
valve on the side of the heater unit......



and sticks out into the incoming air duct area....



it just pulls out......

[x-works]

These can give a bit of trouble now the cars are reaching this age,
and a sure sign that ones playing up is when speeds 1, 2 and 3 don't
work on the heater anymore but position 4 still works fine.
To get a look at the inner bits of the pack the 4 little tabs marked
below are bent back......



allowing the metal cover to pop off......



and then you can see the 3 little coils of wire of varying thickness's
which make up the 3 resistors......



When you have the heater switched to speed 1, the power leaves the
switch and comes to this resistor pack on it's way to the fan motor.
When it enter's the pack it passes through all 3 coils of wire (resistors)
before going on to the motor. As it has had to push through all 3 resistors
the power left when it reaches the motor is small, so the motor only turns
slowly. Hence number 1 speed on the fan switch equals soft blow.
Number 2 speed power only passes through 2 of these resistors,
hence a little more power left when it reaches the motor and as such
the motor turns a little faster. Number 3 speed power only passes through
the one resistor and the fan motor gets a good wack of juice.
And finally number 4 speed doesn't go near the resistor pack at all, it just
heads straight to the fan motor and gives her full 12 volt, warp speed.
And as such when the resistor pack fails your just left with full speed
position 4 or nothing.

In the pic below you can see the route the power takes on it's way out of
resistor pack. Regardless of which speed it is 1, 2 or 3 they all take this path
on the way out. Flowing from the red arrow on the right in the pic, towards
the left, through the set of closed contacts (purple arrow) and on down
and out the bottom to the wire that brings them to the fan motor.



the reason there's a set of contacts is a safety measure. There a fair
whack of juice flowing through these resistor coils and as such they can get
quite hot, hence the reason this bit pokes out into the incoming air, to
help cool it. But, if something happened and they were to get too hot
they could become a fire risk, so, in the pic above you can see a tiny bit
of metal I've coloured yellow (pointed out by yellow arrow).
This metal is bimetallic, meaning that when it reaches a certain temperature
it bends. And in this case, if the resistors get too hot, then it bends like in the
pic below and seperates the two contacts apart.....



now the power can't flow any more on speeds 1, 2 or 3 till the resistors
cool down and the little bimetallic strip also cools and flattens out again
allowing the contacts to touch again. Unfortunately what happens is
these contacts can get dirty over the years until eventually the power
can't cross them anymore, where upon the owner/mechanic takes them
out fu*ks them away and buys a new set, when 9 out of ten times, popping
the cover and using a little piece of sandpaper to clean the contacts up would
have left them good to go for another 10 or 20 years.

Anywho,
next up was the heater radiator and valve. To remove the rad the
3 little screws arrowed below are undone......



however the rad can only slide out so far till the air duct below (red arrow)
gets in the way, so by removing the little screw on the side (purple arrow)
and popping it's two little retainer clips the vent can be removed..........



allowing the rad to side all the way out......



theres two different types of heater motor's fitted to e30 heater's
and as such two different types of radiators to go into them. They
are distinguished by the pipes that fit on to them. Below you can see
mine has one plastic pipe and one aluminium pipe. So it's the aluminium
pipe type. The other type one has two plastic pipes going to it.......



Why do i need to know this you may ask? Well, it should help
you buy the right type of rad, because the two are non interchangeable,
as I proudly display below after buying the wrong one,
fu*k......





Must say a quick thanks to the good folk at C3bmw.co.uk, who
without quibble took back the wrong rad I had chose and promptly
sent me the other one, even though quite a bit of time had elapsed
since the original purchace. Good people.
As you can see below I now had a perfect match......



The reason this is being changed by the way, is at this age the rad's like
to spring a leak and unfortunately the first you'll know about it is when
the interior carpet starts to resemble a swamp. The other part thats
being changed is the heater valve pipe that bolts up to the rad as these
can also fail. Your usually left in no doubt when this fails as when it bursts
it can spew out boiling water over your legs. Nice........



new rad comes with a fat and skinny piece of foam.....



fat one sticks on around the outside and skinny one around the top
like below......



then the new heater valve pipe and the other pipe get bolted back
on with some fresh o rings......

[x-works]

after which the rad slides back into place......



and the little 2 pin electrical plug is reattached to the top of the heater
valve.......



then the motor is popped back into the front section......



and it's retaining clip clipped back down........



wire's reconnected.......



and finally the fan shrouds are refitted. The fan shroud have a little
groove to sit into. Take a second or two to get this right as if you don't
there's a good chance the fan is going to rattle like hell when powered up.......



and then she's just about ready to go back in.......




last thing to do is fit a pair of foam gaskets. As seems to be par for the
course at this stage I ordered the wrong one. I'm still convinced I ordered
the right part number, however this is what arrived at the main dealer....



It's the gasket for the other type of heater motor. As you can see though
they're pretty much similar, and a quick chop with the stanley knife
and they were a lot more similar......





The other gasket was for the inside piece of the heater unit......





After that, the grommet gets popped back in the bulkhead.......



and the heater unit gets hammered back in, making sure the 4 mounting
bolts pop through their little hole in the scuttle area so you can refit the
4 nuts to them (red arrows), and the two pipes pop through the big
grommet in the bulkhead (purple arrow).......



all done.....



Hope to get the next final bit of this update up in the next day
or two.
Till then...........

[Royalratch]

You're slacking dude - need more than a whole brake and heating system rebuild to get through the day!

[oi_oi_savaloy]

Not only an epic thread and rebuild (and knowledge of an e30!) but bloody funny in the process! A great read. I'll say it again - if I had a hat it would be suitably doffed to you sir!

[Gortour]

Zone Gold for definite... Absolute quality from start to finish.