E30 technical help

[RossDavies]

Hi everyone, I'm new to the site and have recently purchased an 87 325 sport which has sadly developed a missfire and blue smoke. I'm mechanly minded with 15 years experience as a bus mechanic but always value good advice from the right people. I can't look at the car at the mo because it's in self storage in a covid hotspot so can't see it, I'm looking for anybody with previous experience of this fault before I get my hands on it again. The blue smoke is the red flag for me, but maybe somebody has come across this from just a distributor cap or something? Any ideas? I'm just looking for previous fixes please as I can't look at her at the mo. Cheers oh and here's some pictures

[ah]

Sorry mate I can’t help you with your fault but I can assure you there will be someone on here who can, put this post on “E30 technical Help“ on this forum and look out for a guy called Brianmooore, what he dosnt know about E30s ain’t worth knowing o by the way that’s a corking Tec-1 you’ve got there,good luck.

[RossDavies]

Thankyou very much will do bud

[Brianmoooore]

Did both of these symptoms start at the same time?
As you probably know, blue smoke is burning oil, and generally not a good sign! If it appears after the throttle is closed, it could be as simple as failed valve guide seals, or slightly more seriously, worn exhaust valve guides - the only part that I would normally expect to find out of spec. on a 'looked after' M20B25 up to 200,000 miles +.
If it's constant blue smoke, and in considerable quantities, I'd be looking at a serious failure in one cylinder bore - damaged piston/rings. If there's enough oil getting into the combustion chamber it could have fouled the spark plug, causing the misfire.
First thing to do is to remove all of the spark plugs and compare the colour of the tips, to see if one is different from the rest.

[RossDavies]

Sorry Brian about the duplicate posts. Yes they did start the same time, sometimes it misses and some times it doesn't. It only blue smokes when it misses. What I noticed as well is last time I drove it it would let out plumes of blue smoke only after coasting on the motorway then giving it some Welly. Now it smokes when revved up standing still. I'm just going to have to wait till I can get my head under the bonnet so I can do the investigative steps. Was posting on here only hoping that somebody would say they had the same simptoms for something silly. As I can't get to the car at the moment cos of this shitty virus was fishing for ideas instead.

[Brianmoooore]

Short reply is, no, it's not a common fault on a BMW. Ford or Vauxhall, etc., then yes, very common, but not on something of BMW quality.
Keep us updated when you can get back to the car.

[RossDavies]

Will do mate

[RossDavies]

While I got you on here what do you think the values of the sport editions will be in say 10 years? Not that I'd ever sell it of course...

[Brianmoooore]

If I could predict the value of a 'sport' in ten years time, I would have bought a few n 2010, along with an M3 or two.
TBH, I've never really understood the premium price for a 'sport', when it's just a 325i 2 door with mtec kit, sports suspension, CR gearbox and LSD - all ordinary options that could be specified by any E30 purchaser. Only unique part was a black headlining, which, although not on the standard options list, could be asked for as a special order

[RossDavies]

Thanks for making me feel shit for buying a 'sport'...

[tha881]

While I got you on here what do you think the values of the sport editions will be in say 10 years? Not that I'd ever sell it of course...

All depends on condition, they usually go from 5k to 25k (although a low mileage tech 2 sold recently for around 50k). I think weve seen the largest spike in values over the last few years (mainly on the back of the m3) but they will continue to creep up I'm sure

[Brianmoooore]

I've not got anything against the sport, although I consider four door E30s to be better proportioned than the two door, and certainly wish I'd bought a couple ten years ago. It's just that I don't understand the massive premium over a 325i for a few pre ticked option boxes. If BMW had given it an extra 20 bhp, then I'd consider it worth the extra.
I have two Laguna Green 316i tourings in my collection. One is a Lux, and the other has a factory fitted Mtec II body kit, LSD and sports suspension. I've no idea how they compare in value, all other things being equal, but I'll bet it isn't the same proportionate difference as with the 325i and sport.

[ChrisHC]

Welcome to the zone, that is a very nice looking car, I have a very similar one in Dolphin Grey. When I bought mine 5 years ago there did not seem to be the same premium for the Sport over the 325i, at any rate I was not aware of paying it. I was certainly not expecting the value to more than treble, but it is pleasing that it has. I think it really moved from 'old car' to 'classic car' status in that time. With the comparatively few M3s made soaring to stratospheric prices, I suppose also that the 325i is the nest best thing, and although the Sport just has the more sporting options available on the 325i, it does carry the M badge, and people must be prepared to pay for that. Irrational things can affect car prices, I remember the death of Enzo Ferrari causing a sudden jump in Ferrari values, as though he was some artist who could produce no more masterpieces.

The question is what car is going to shoot up next, personally I feel the E46 might be ripe for classic status, I certainly hope so as I have just bought one, to use I hasten to add, not as an investment. There are those who say that the E46 and the E39 were a highpoint for BMW, before Chris Bangle got to work and worse was to come with the current oversized grilles, but that is another story.

Anyway, enjoy your great car.

[martauto]

The question is what car is going to shoot up next, personally I feel the E46 might be ripe for classic status, I certainly hope so as I have just bought one, to use I hasten to add

I have had two e46 coupe 330`s (both lost to other idiots ) and now I have an e46 325 cab se.
I fully agree with you about the future status of these cars as they , when looked after , are "proper" cars to live and drive with.
I very rearly see an e46 now t`up north and have only seen two cabs post face lift but did see two coupe`s until I lost my job but what a car you get for your cash, if it is right !!!!

Mart.

[BristolE30]

Thanks for making me feel shit for buying a 'sport'...

You can part you way up to a ‘sport’

[Cloggy Saint]

Aha, the 'sport' debate, haven't had one of these for a while, it used to get quite feisty
I'm with Brian, it's a parts bin special that's been lucky enough to gain elevated status, not that there's anything wrong with that. If I knew then what I know now I'd have picked one up for 3k ten years ago.

[Contours]

Its the word 'sport' that costs the extra 5 grand.

[Brianmoooore]

Its the word 'sport' that costs the extra 5 grand.

That's a lot of money to pay for a black headlining!

[RossDavies]

So... An update on my beemer. Firstly i feel the price i payed is fair as, yes its a 'sport', but its the original m tech 1 kit in pristine condition which did it for me. Its rumoured that only around 280 were made for the uk? Plus collectors want 'sport stamped on the logbook. So i have a good investment. I always wanted a sport mtech 1, but had to pay 18k before they are out of my reach. This one (pictured above) also has had a full rebuild on the body and drivetrain (clearly apart from engine internals). New inner and outer arches,(front and rear) new rear panel, windows out respray, and not a single component is missing. Not a single plastic trim under the bonnet, which to me is worth the cash. (Excuse me while i justify destroying my wallet). The last two I've seen sold for 21k anyways, so i am up 3 grand.

Any ways, i removed spark plugs, and number one spark plug was HEAVILY caked in oil. Removed the head to find the inside of number one intake port was soaking with oil. I knocked the valve spring off to find the valve was badly worn through the guide and scratched, and was like a cock in a sock (big gap around the seal which was hard also).

So i sent the head to South Wales piston services, who inspected, replaced all guides, replace the valve which they said was bent?? and all seals, adjusted valve clearances and gave it back to me with gaskets and bolts for £450.

Heres where i fucked up. I ASSUMED that because i had found that problem with that port, on the cylinder that was showing oil, that there was no need to check the bottom end. So rebuilt.( New timing belt ect)

Started the engine to my horror it was the same( if worse). Howling out blue smoke and misfire. Removed plugs again, number one caked in oil again. Off with the head again, pistons out.

Number one cylinders rings had a gap of around 5mm, with the oil ring having no ridges left, totally flush and useless.

Also there was multiple vertical scratches at the very top of each bore, (i really should have seen these when the head was off the first time). The scratches were mainly in the dead zone but did reach down in to the top 2 rings area.

After much deliberation, I decided to attack the scratches with a block type glaze buster, just enough so that the scratches could not be felt. Manage to get a lovely feeling bore, but obviously removed a minute amount of material. The new rings were tested in the bore, i had a gap of around 0.65 mm (1.5 out of tollerance) but proceeded to button her up.

It worked. The blue smoke and misfire is gone.

But i do have a problem. The mixture is out. It is idling rough, but dives fine. My god the fumes are toxic, it burns your eyes and makes you feel sick. So i am currently in the process of trying to find out why. I will be smoke testing the intake, and checking them valve clearances ( i dont trust the machine shop). Also, it runs cold. Has done since i bought it so will be replacing the thermostat to see if that helps.

I also have a question for anybody that knows, on the older throttle bodys, which is what mine is, there is an extra icv bypass adjustment screw, and i fucked about with it. Does anybody know how it should be set? I will update my findings with the mixture problem but any advice would be much appreciated.

[RossDavies]

So... An update on my beemer. Firstly i feel the price i payed is fair as, yes its a 'sport', but its the original m tech 1 kit in pristine condition which did it for me. Its rumoured that only around 280 were made for the uk? Plus collectors want 'sport stamped on the logbook. So i have a good investment. I always wanted a sport mtech 1, but had to pay 18k before they are out of my reach. This one (pictured above) also has had a full rebuild on the body and drivetrain (clearly apart from engine internals). New inner and outer arches,(front and rear) new rear panel, windows out respray, and not a single component is missing. Not a single plastic trim under the bonnet, which to me is worth the cash. (Excuse me while i justify destroying my wallet). The last two I've seen sold for 21k anyways, so i am up 3 grand.

Any ways, i removed spark plugs, and number one spark plug was HEAVILY caked in oil. Removed the head to find the inside of number one intake port was soaking with oil. I knocked the valve spring off to find the valve was badly worn through the guide and scratched, and was like a cock in a sock (big gap around the seal which was hard also).

So i sent the head to South Wales piston services, who inspected, replaced all guides, replace the valve which they said was bent?? and all seals, adjusted valve clearances and gave it back to me with gaskets and bolts for £450.

Heres where i fucked up. I ASSUMED that because i had found that problem with that port, on the cylinder that was showing oil, that there was no need to check the bottom end. So rebuilt.( New timing belt ect)

Started the engine to my horror it was the same( if worse). Howling out blue smoke and misfire. Removed plugs again, number one caked in oil again. Off with the head again, pistons out.

Number one cylinders rings had a gap of around 5mm, with the oil ring having no ridges left, totally flush and useless.

Also there was multiple vertical scratches at the very top of each bore, (i really should have seen these when the head was off the first time). The scratches were mainly in the dead zone but did reach down in to the top 2 rings area.

After much deliberation, I decided to attack the scratches with a block type glaze buster, just enough so that the scratches could not be felt. Manage to get a lovely feeling bore, but obviously removed a minute amount of material. The new rings were tested in the bore, i had a gap of around 0.65 mm (0.15 out of tollerance) but proceeded to button her up.

It worked. The blue smoke and misfire is gone.

But i do have a problem. The mixture is out. It is idling rough, but dives fine. My god the fumes are toxic, it burns your eyes and makes you feel sick. So i am currently in the process of trying to find out why. I will be smoke testing the intake, and checking them valve clearances ( i dont trust the machine shop). Also, it runs cold. Has done since i bought it so will be replacing the thermostat to see if that helps.

I also have a question for anybody that knows, on the older throttle bodys, which is what mine is, there is an extra icv bypass adjustment screw, and i fucked about with it. Does anybody know how it should be set? I will update my findings with the mixture problem but any advice would be much appreciated.

[RossDavies]

Fixed, valves were set way too tight, all apart from one, which was 0.55mm. which would explain my loud tapping noise. So i wouldnt recommend south wales pistons to anybody!! Also adjusted the throttle body so it was open just a fraction, and adjusted the TPS to suit. Its never run so smooth, and also I have the pleasure of being able to adjust my idle speed using that extra ICV bypass screw which I mentioned on the throttle body. I have it ticking over SUPER smooth at 800rpm, (i know it should be 750 but added a little extra to help with my lightweight flywheel). No more dipping to almost a stall after revving, and no more gear train rattle on tickover. I am very happy!! Also, removed sparkplugs whilst adjusting tappets, and no oil fouling at all! Now i have a car which is fully mint, and can just enjoy.

[RossDavies]

Oh and its a sport...

[Brianmoooore]

What extra bypass screw on the TB???

[RossDavies]

What extra bypass screw on the TB???

As you look at it on the car from the passenger side, its on the top right, opposite the icv port. Its a flathead screw in a downward vertical hole. Just towards you from where the brake vacuum pipe fits. It seems to me that it just allows adjusted air to pass the butterfly, without using the pedal and activating the tps? I read that only the earlier throttles have this?

[Brianmoooore]

Can you put up a pic?

[RossDavies]

Yeah when i get home il take one. It says about it on your e30 zone wiki, if you search for motronic 1.0. maybe i have this version??

[RossDavies]

Here you go photo above

[steve_k]

never seen one like that before,

but you defiantly want to cap off the TB heater hoses on the other side (the two little stubs).

[RossDavies]

never seen one like that before,

but you defiantly want to cap off the TB heater hoses on the other side (the two little stubs).

Yeah it comes real handy, because you can wind it in until it runs rich and splutters or wind out until it leans out and revs up to where you want it. Wondering have i got motronic 1.0. only way to check is look at the ECU i guess. Theres thorough setting instructions for motronic 1.0 on here. But i'm not sure whether to mess with it again as it seems nice. Although when it was running lumpy as hell before i corrected the tappets, im sure it was faster, more responsive, but cant be sure. All i can say is its very smooth now. Maybe il have a fiddle.

Why blank off the hoses?

[RossDavies]

I have some pictures of what was causing my blue smoke and misfire

[RossDavies]

And here's the condition of the cylinders with scratches(could feel multiple with finger nail, especially cylinder 1)

[RossDavies]

And here is after i wore my glazebuster out by honing until smooth. (Can still see scratches, but cant feel)

[martauto]

Talk me through the "Glasebuster", as I`m curious please.

Mart.

[biffer]

Have been out to look at my July '87 325 engine and it also has that extra screw on the throttle-body.

[flybynite]

Talk me through the "Glasebuster", as I`m curious please.
Mart.

Think he means honing tool