88 325is cooling/temperature issue

[Bill-h]

Good day all.
Been fighting an issue on an E30 I have for quite some time now and I am stumped.

The car.
'88 325is Auto, 211k miles

Symptoms:
Car starts and runs well, When started and idling, it comes to temp (Needle in the middle/12 o'clock) and holds.
When driving, it comes to temp (Needle in the middle/12 o'clock) and holds.
Coming OFF the road, coming to a stop.
temperature climbs. If placed in neutral and rpm's brought above 2000 RPM, cools back down.

What I have done.
New water pump, new radiator, new fan clutch, new belts, new fan shroud, new fan blades, replaced head with a freshly reman'd one. and finally, new BMW thermostat.

Did all of this in stages, not all at once.

When I put the BMW thermostat in, I added water wetter.
NOW, when driving, the temp climbs to just under 3/4. Temp still climbs when I come to a stop.

So,, I made it WORSE!!!
WTF man.

Help???

Bill

[paultv]

What thermostat did you fit? I mean temperature wise??

Paul:-)

[Bill-h]

What thermostat did you fit? I mean temperature wise??

Paul:-)

I did not specifically look at the thermostat to see if it was stamped, RealOEM claims it's an 80c one. the one I pulled out was stamped 80.

[martauto]

Have you checked the little brass nut behind the dash onto the temp gauge ?
It can work loose and even fall off giving in both cases a false reading.

Mart.

[Bill-h]

Have you checked the little brass nut behind the dash onto the temp gauge ?
It can work loose and even fall off giving in both cases a false reading.

Mart.

I thought of that as the tach jumps around. I have a new set of gears in and will be rebuilding the instrument cluster this evening.

[paultv]

Yeah, it should be 80c, and a rise in running temp when you stop is pretty usual - at least my 325 M20 does it. ( no electric fan )

Paul

[arrisbmw]

is the viscous fan working correctly , some of the cheap viscous units are crap.
when idling with a hot engine you should not be able to stop the fan with a rolled magazine.

and a piece of paper against the Front grill should hold there due to the suck from the fan.

does the temp drop if you put the blower on max heat ? heater inside

[arrisbmw]

could be a faulty coolant sender or wiring from it..

[arrisbmw]

Good day all.
Been fighting an issue on an E30 I have for quite some time now and I am stumped.

The car.
'88 325is Auto, 211k miles

Symptoms:
Car starts and runs well, When started and idling, it comes to temp (Needle in the middle/12 o'clock) and holds.
When driving, it comes to temp (Needle in the middle/12 o'clock) and holds.
Coming OFF the road, coming to a stop.
temperature climbs. If placed in neutral and rpm's brought above 2000 RPM, cools back down.

What I have done.
New water pump, new radiator, new fan clutch, new belts, new fan shroud, new fan blades, replaced head with a freshly reman'd one. and finally, new BMW thermostat.

Did all of this in stages, not all at once.

When I put the BMW thermostat in, I added water wetter.
NOW, when driving, the temp climbs to just under 3/4. Temp still climbs when I come to a stop.

So,, I made it WORSE!!!
WTF man.

Help???

Bill

i think i,d be tempted to put the old stat back in, even though a pain.

[Bill-h]

is the viscous fan working correctly , some of the cheap viscous units are crap.
when idling with a hot engine you should not be able to stop the fan with a rolled magazine.

and a piece of paper against the Front grill should hold there due to the suck from the fan.

does the temp drop if you put the blower on max heat ? heater inside

Viscous fan is working correctly, can NOT bring it to a stop while hot.

Temp does not change with Heat on or off, Does not change with AC on or off, Does not change with it 70 or 95 deg outside.

could be a faulty coolant sender or wiring from it..

I have not checked the wiring.

i think i,d be tempted to put the old stat back in, even though a pain.

Sadly, the wife emptied the trash

[Bill-h]

Yeah, it should be 80c, and a rise in running temp when you stop is pretty usual - at least my 325 M20 does it. ( no electric fan )

Paul

In the ,, 15 or so E30's I have been involved with, I have never seen the temp climb up when coming to a stop and the engine still running.



Well, I did on the race car, but,,,,, Mods.

[arrisbmw]

take the stat out and see what happens.

iirc if its rich , i,e to much petrol to air causes the engine to run hot.

The ”aperfect”a fuel air mix is called a ”astoichiometric fuel ratio.”a This is 14.7:1 , this is what the computer is trying to maintain all the time. but if a sensor is tell the ecu wrong info then obviously the "stoichiometric" cant be right.

[nick496]

Have you checked the little brass nut behind the dash onto the temp gauge ?
It can work loose and even fall off giving in both cases a false reading.

Mart.

I thought of that as the tach jumps around. I have a new set of gears in and will be rebuilding the instrument cluster this evening.

Did you end up tightening that nut in the end?
I had a similar issue on my old 325i. Took it to the mechanics to run a pressure test (actually to bleed it properly), they put the temp gun on it, the temps were fine, so just tightened the nut on the back of the temp gauge. Worked a treat after that.

[Bill-h]

I rebuilt the cluster last evening (replaced odo gears, cleaned everything including the contact surfaces UNDER the nuts and tightened the nuts).

Then,, it was downpouring. Didn't get the cluster back in.

Plan on putting it back together tonight.

[Bill-h]

[DanThe]

Is the electric fan working when air conditioning is turned on?
My E30 struggles to stay cool in heat/traffic with the air conditioning on but I have no viscous fan, an 80/88 switch in the rad will bring the elec fan on earlier which will help your situation.

The condenser rad will be having an effect on cooling as air needs to pass through this before it gets to the coolant rad, if its old and blocked up then get it replaced.

Also fitting a 'hot climate' or 'tropical' rad which is bigger in capacity will help

[arrisbmw]

i didn,t think they had electric fans unless retro fitted.
If your temp does not drop when you put heater on its not an issue with the rad. as you said its new .
When i had a old blocked rad and car overheated if i put the heater on full blast it would cool down , because the heater matrix is taking the heat from the sys helping the main rad.

what you need is an infra red thermometer , just point and it tells you the exact temps. you should be able to work out from this whats going on , your be able to tell when the thermostat opens ( top hose gets hotter ) and your see the bottom hose getting warmer as water passes thru , (but not as hot as the top hose as the water is being cooled by rad )

as your temp gauge could be wrong. and mis-leading you.

I understand the 6 pots are hard to bleed the cooling sys, maybe you still got air trapped.

[Bill-h]

Is the electric fan working when air conditioning is turned on?
My E30 struggles to stay cool in heat/traffic with the air conditioning on but I have no viscous fan, an 80/88 switch in the rad will bring the elec fan on earlier which will help your situation.

The condenser rad will be having an effect on cooling as air needs to pass through this before it gets to the coolant rad, if its old and blocked up then get it replaced.

Also fitting a 'hot climate' or 'tropical' rad which is bigger in capacity will help

The AC fan (Electric in front is the condenser) does run when the AC is on.
Verified again last night that the Viscous clutch IS locking up when hot.
Wondering if I have the correct fan blades??? It's damm quiet and there is @ 1" room between the end of the blades and the shroud.

Any idea where I could get a "tropical" radiator??

Also thinking of running an "E" water pump pulley, they are smaller. this would drive the pump/fan faster.

i didn,t think they had electric fans unless retro fitted.
If your temp does not drop when you put heater on its not an issue with the rad. as you said its new .
When i had a old blocked rad and car overheated if i put the heater on full blast it would cool down , because the heater matrix is taking the heat from the sys helping the main rad.

what you need is an infra red thermometer , just point and it tells you the exact temps. you should be able to work out from this whats going on , your be able to tell when the thermostat opens ( top hose gets hotter ) and your see the bottom hose getting warmer as water passes thru , (but not as hot as the top hose as the water is being cooled by rad )

as your temp gauge could be wrong. and mis-leading you.

I understand the 6 pots are hard to bleed the cooling sys, maybe you still got air trapped.

Bleeding the system isn't that hard, if you do it right (Bleed screw on the top if the t-stat housing) . Confident that system is bled correctly.

Will "Borrow" the calibrated infrared thermometer from my analytical lab.

B

[arrisbmw]

good luck hope you get it sorted.
let us know how you get on. and what the issue is/was

[ah]

Have you checked the little brass nut behind the dash onto the temp gauge ?
It can work loose and even fall off giving in both cases a false reading.

Mart.

I hope I didn't do the wrong thing,my brass nut fell off and short term replaced it with an ordinary steel nut and never replaced it,have I done the wrong thing ?

[Bill-h]

I would think that as long as it holds tight, you'd be fine.
The nut pulls against plastic.