E36 328i - overheating - help with self diagnosis!

[mackt 1]

Hi

The 328 is overheating when sitting idling for a few minutes, or stop start driving in town.

Everything is fine on the open road, needle is rock steady in the middle of the guage.

Oh and I'm loosing coolant. need top up fortnightly

Just hit 100,000km

I've booked it in next week to get sorted.

I think a new waterpump and thermostat are no brainers, but I was wondering about the viscous coupling on the fan and a new coolant reservoir.

Second opinions actively sort.

Thanks

[Mark 178]

Let me know the outcome.... my 325i is doing the same, though not quite as severely. Will be interesting to see what needs replacing.

[Braeden320 0]

Link

Another Link

Another...

Linkage

Another..

Bit of light reading for ya!

Found all of the above using the search button located on the top right hand side of your screen, There is heaps of info on here as it is a common fault on the e36 and many people before have had the same issue.

[will 169]

You need to find out where you are loosing coolant from. That loss may be giving you an air lock in your system which would help overheating. This is the first thing you need to do. Meantime bleed the system properly and see if that helps at all.

When the car is at operating temp you should not be able to easily stop the viscous fan. I use a heavy leather welding glove and carefully stick my well-protected fingers gently onto the blades from the engine side and gradually try to stop the fan with increasing pressure. When the car is cold this will be easy to do, but should be very difficult when hot. BUT BE CAREFUL!!! If you can stop it easily as when cold, replace the viscous coupling.

Check that your radiator fins are clean, especially if you have an aircon radiator in front. Use a pressure blaster set on fan and blow through the grill etc to force any dirt out.

Maybe the waterpump belt is slipping??

Will

[pureboiracer 0]

sounds like a fan prblm to me. overheating in traffic or just sitting round and causing the coolant to boil and exit out the overflow of the expansion tank

[mackt 1]

Thanks for the advice so far, I think I'll go and stick my hand in the fan and see what happens !

[Yuen 16]

It sounds like the fan clutch is faulty. Good idea to replace the thermostat, water pump like you said... if the hoses and expansion tank are old, I'd do those as well. I think some people change the plastic thermostat housing to a metal one which is more durable, so you might want to consider that.

You need to find out where you are loosing coolant from. That loss may be giving you an air lock in your system which would help overheating. This is the first thing you need to do. Meantime bleed the system properly and see if that helps at all.

I agree. My E36 used to have a slow coolant leak and I'd bleed all the air out of it and it would drive great for weeks/months, then it would overheat again one day and I'd find it was due to air displacing all the lost coolant.

[Mark 178]

FYI.... check your fusebox first..... fuses 16 and 41 are for the Auxillary fan. I did this today and fuse 41 was blown. Popped a new fuse in and now it's all fixed woohoo!!!

[mackt 1]

FYI.... check your fusebox first..... fuses 16 and 41 are for the Auxillary fan. I did this today and fuse 41 was blown. Popped a new fuse in and now it's all fixed woohoo!!!

Thanks for that pearl of wisdom gannetboy - #41 blown - need to go for a blat and see what happens.

[mackt 1]

Well it would appear that was the fix I needed - ole fuse 41!

Still think I'll do the water pump and thermostat.

Thanks again gannetboy

[Mark 178]

Thanks again gannetboy

No worries! Was just a hunch I had while cleaning the car on Saturday, glad I could help!

[jpp 0]

I think a new waterpump and thermostat are no brainers, but I was wondering about the viscous coupling on the fan and a new coolant reservoir.

Spin the fan when car is off, if it stops relatively quickly.... it's still good.

Maybe best to compare to another car...

[mackt 1]

Spin the fan when car is off, if it stops relatively quickly.... it's still good.

Maybe best to compare to another car...

Went for a drive up to Queenstown and back today, no probs at roadwork stop/go's and then dawdled around town for a while when I got back, that usually would have had the needle climbing.

Just did the cold fan check, looks like it's a keeper - thanks for that.

[mackt 1]

All sorted - new waterpump today, looks like I had been a very lucky boy that it hadn't disintegrated while driving with enthusiasm

Thermostat done as well