View Full Version : Overheating on 89 535I

10-12-2008, 07:48 PM
Driving my wifes 89 535I the other day, noticed the temp guage going up, right after I left the gas station. Got going down the road, and it went back down to the middle. Went about another 2 mile, stopped at a light and noticed it going back up. Light turned green, temp guage goes down. Got home, let the car sit in the driveway, idle for about 20 minutes, with the A/C on, didn't move an inch.

1) The coolant in the resovior is brown, is bmw coolant brown?
2) Is there a way to check how much coolant is in the radiator, can't locate a cap
3) How do I flush the system?

bimmer dot info
10-13-2008, 08:31 AM
1) BMW coolant should be blue.
2) Part 2 http://www.realoem.com/bmw/showparts.do?model=HD23&mospid=47408&btnr=17_0001&hg=17&fg=05
3) Drain plug is part 2 http://www.realoem.com/bmw/showparts.do?model=HD23&mospid=47408&btnr=17_0000&hg=17&fg=05
There is also a block drain. Parts 3 and 4 http://www.realoem.com/bmw/showparts.do?model=HD23&mospid=47408&btnr=11_0133&hg=11&fg=10 located under the exhaust on the psgr side.
Remove both of those and flush it with a running garden hose. If you really want to clean it out you can fill and bleed the radiator with plain water and drive it for a few miles and drain and flush it some more.
After that you fill with 50/50 antifreeze and water and bleed the system a bunch.

Back to the problem... Sounds like your aux electric fan still works but the clutch on the engine driven one is bad. Check the engine driven fan for proper function by running the car till it is warm and trying to stop the fan with some rolled up news paper while the engine is idling.

10-13-2008, 10:31 AM
Thanks for all the info, I'll check all this out tonight.