temp gauge up and down....

[BMWe34CMM]

97 e36 sedan. Just picked it up with 87,000k on it Im driving yesterday and i see that its still in the cold area when i had bee driving for about 25 minutes. then i look again and its in the warm area maybe over one notch , then it goes back to cold... seems that i have to do my cooling system what aproach do you think i should go. i have a wholesale discount at BMW so if factory is what you suggest then thats what i will do... what else do you suggest i do since im in there? alum housing?

[turb02]

Doing a search on this forum will yeild great info.

I would suggest doing all the hoses, theromstat (this sounds like your problem area), thermo cover (aluminum one), water pump with metal blades, and possibly a zionsville radiator since it gets rid of the composite sided radiator.

My .02

[BMWe34CMM]

i appreciate ur suggestions, thanks a lot!

[turb02]

not a problem. The E36 is notorious for a bad cooling system. It has been discussed many times on this forum. I personally have been a victim of the weak composite radiator endtanks. I didnt catch it in time and had a cracked head because of it. Hence the 332is listed below.

[BMWe34CMM]

UNDERSTOOD. ILL DEF FOLLOW UR advice on the cooling system. any particular brand besides the ones u listed on cooling system parts?

[turb02]

aatuning.com (active auto) should have the thermo housing and waterpump.
zionsville (not sure who else sells it) has the radiator.
the hoses and thermostat can be purchased at the dealer or bavauto.com or any other bmw shop or sponsor on this board that is available for you.

[Nicklle36]

If the temp gauge goes up and down and keeps getting back in the cold area while driving (particularly driving at higher speeds), the car is overcooling. Then the culprit it most likely the thermostat. Not very hard to change, I've done it on my car last fall.

[racermp]

thrmostat, if u drive on the freeway and it cools too much, drive in slow areas and it warms back up, thermo broke and stuck open. common problem on benz and bmw

if it's normal temp on freeway and overheating in city, it's either thermostat or fan clutch (most likely fan clutch)

[BMWe34CMM]

yeah it doesnt over heat at all....

[Furious]

its gonna be your thermostat, its sticking open, its suppose to be a failsafe for our thermostats to fail stuck open, however sometimes they do fail closed (bad), id replace that and the housing like mentioned before and if you have a chance check out the hoses and rad spigots (the plastic necks that the hoses attach to on the rad) if they are brittle id look into replacing the rad in the future.

like everyone said e36's have a terrible cooling system setup. typically once the car overheats a bit just once, the rest of the system is ready to be replaced to, im only saying to check the whole system out because its a new car to you and you dont know what the previous owner did.

[jaguax]

The Zionsville radiator will cost you a small fortune. The OEM radiator is fine as long as you replace it every 100k or so. You can get it for ~155 shipped brand new. Talk with the member bimmerzone. He's a vendor on these forums and he'll set up you up with the cooling system parts that you need for good prices.

[bamboopatch]

I changed everything in my cooling system, and still have this problem of the thermostat in the blue, however when i slow down it will go into the middle. What is that about.

[exodus454]

I changed everything in my cooling system, and still have this problem of the thermostat in the blue, however when i slow down it will go into the middle. What is that about.

Faulty or improperly installed thermostat, I would think.

[Mscire2]

goto bimmerworld, they have a full cooling system overhaul kit that comes with a radiator and everything else you could think of for like 300ish with a stock radiator and i think another 100 gets you an all aluminum one.

[turb02]

I've never heard of this happening. It may be the fan clutch along with the tstat

[BMWwey]

This happens to me all the time. I always thought it was normal operation. The temp gauge gets colder depending on how cold it is outside in conjunction with very passive driving. This also used to happen to my former E34 so I always thought it was normal. Are there any adverse effects of the engine running colder than the "normal" operating temp?

BTW Mscire2 has a fantabulous car . I have the same color car. I was debating whether to go with smoked or just clear indicators and you have convinced me to go with clears. You have any other pics?

[jenjos]

Interesting. 97 318i with 250K. Overheated and took it to local indy and resolved all overheating issues. Now as stated, the car on highway runs just a notch over blue and in city runs normal......since it doesnt overheat i haven't paid much attention to it

is it really cause for concern?.....

[b00sted n00b]

mine does the same. goes from normal to cool and back. never overheats. does this even need fixing if it doesnt overheat?

The only drawback in seeing is that the coolant isnt a consistant temperature, I would think the effects from this would be negligible.