E36 - coolant temperature
Discussion
My E36 323i is mainly used on tarck (road use is limited to driving to and from the track)
The car has never had a cooling issue - the gauge needle always sits perfectly at 'midday'. I replaced the water pump at the start of the year, purely preventatively, to ensure it had a metal impeller model.
At the last two track days, neither of which were particularly hot, we have had the needle start to creep up towards the 'red zone'. The car is certainly being driven ever harder as my son has developed his track skills, so it's certainly spending good 20 min sessions at no lower than 4,000rpm. As soon as you back off when on track though, the temp needle starts dropping immediately.
My mechanic says it's inevitable as the car was never designed to be driven so hard for such a sustained period but, whilst I have some sympathy for that argument, I can't help but see plenty of E36s easily completing races much longer than our track sessions and, indeed, endurance races too.
So, what's the advice?
Add an oil cooler so the water isn't having to do all the work?
Replace the thermostat and radiator to be sure that the flow is maximised?
Something completely different...?
The car has never had a cooling issue - the gauge needle always sits perfectly at 'midday'. I replaced the water pump at the start of the year, purely preventatively, to ensure it had a metal impeller model.
At the last two track days, neither of which were particularly hot, we have had the needle start to creep up towards the 'red zone'. The car is certainly being driven ever harder as my son has developed his track skills, so it's certainly spending good 20 min sessions at no lower than 4,000rpm. As soon as you back off when on track though, the temp needle starts dropping immediately.
My mechanic says it's inevitable as the car was never designed to be driven so hard for such a sustained period but, whilst I have some sympathy for that argument, I can't help but see plenty of E36s easily completing races much longer than our track sessions and, indeed, endurance races too.
So, what's the advice?
Add an oil cooler so the water isn't having to do all the work?
Replace the thermostat and radiator to be sure that the flow is maximised?
Something completely different...?
It opens earlier so the cooling starts earlier, so it does not get so hot to start with, the car will fun cooler all the time not just on track. But, if your car does not have the additional pusher fan I would probably go with this, although a stat would not hurt.
Your VC works correctly, and has a full complement of blades on the fan?
Your VC works correctly, and has a full complement of blades on the fan?
Edited by E30M3SE on Friday 14th October 16:34
That's possible. I'm seriously thinking of swapping out the radiator so maybe running a coolant flush immediately prior to fitting it would be a good idea?
Popped into my local BMW dealer this morning, asking if I could compare the thermostat for an E36 with that of an E28 525/528 which were 80 degree units. They had neither in stock but have orderedd them for me to have a look at next week.
While the chap was serving me, he popped out to the workshop to ask someone about my 'plan'. Anyone would think I'd asked to sleep with the technician's daughter: the parts bloke came back in, visibly alarmed, telling me that car would probably not run properly anymore if I put an 80 degree (instead of 88 OEM) 'stat in and that the map would be confused and that the whole car would misbehave etc.
How much truth in the tech's response? I don't run an OEM map anyway and I certainly never put the car's heating on. Is the general running really going to be affected by the 'stat opening a little earlier?
Popped into my local BMW dealer this morning, asking if I could compare the thermostat for an E36 with that of an E28 525/528 which were 80 degree units. They had neither in stock but have orderedd them for me to have a look at next week.
While the chap was serving me, he popped out to the workshop to ask someone about my 'plan'. Anyone would think I'd asked to sleep with the technician's daughter: the parts bloke came back in, visibly alarmed, telling me that car would probably not run properly anymore if I put an 80 degree (instead of 88 OEM) 'stat in and that the map would be confused and that the whole car would misbehave etc.
How much truth in the tech's response? I don't run an OEM map anyway and I certainly never put the car's heating on. Is the general running really going to be affected by the 'stat opening a little earlier?
THIS THREAD IS USELESS WITHOUT PICS etc etc.
The coolant temp gauge is buffered so won't necessarily react quickly or show changes in real time. However you say it does show an increase under hard driving and reverts to normal when under less load, which you'd expect.
I would change the radiator and flush. The BMW cooling system on the 6 cylinders has little margin for error built in and an older rad could be inefficient. May as well change the expansion tank, water pump and tubes while you're there.
That should do it. You only need one episode of overheating and the all-aluminium engines are goosed
The coolant temp gauge is buffered so won't necessarily react quickly or show changes in real time. However you say it does show an increase under hard driving and reverts to normal when under less load, which you'd expect.
I would change the radiator and flush. The BMW cooling system on the 6 cylinders has little margin for error built in and an older rad could be inefficient. May as well change the expansion tank, water pump and tubes while you're there.
That should do it. You only need one episode of overheating and the all-aluminium engines are goosed
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