Question on BMW 3-Series E36 water pump & bleeding?

Hi Guys / Wayne,
Thanks for the support. Replaced the water pump & thermostat.
Flushed, cleaned & refilled the system and bled it. But the car still overheats!
The pipe to the radiator gets hot; the return pipe remains cool. Is this because the water is not circulating? I removed the radiator flushed with water from the tap - good pressure. Applied the hose to the small pipe from the radiator to the block, - no obstructions.
What else could be the problem?

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This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: BMW Water Pump Replacement

[Wayne 962]

Well, the top of the hose being hot and the bottom being cold is sort of the way it's supposed to be. If both were cold, then there would be nothing circulating. Hot on top, cold on bottom means the radiator is doing its job - cooling the coolant. I'm guessing that you have an air bubble in there - try bleeding the system 3-4 more times with the heater on. Sometimes these BMW cooling systems can be difficult to extract all of the air from.

- Wayne

[coolbear1]

E36? If it has an m50 engine it is most likely air in the system. I have had several 6 cylinder BMW automobiles, all six cylinder, but the 93 i still have with the M50TU engine is the worst for getting the air out by far. I have replaced every thing there is to replaceon the cooling system some things several times, and I still cant get the air out the first time. Honestly, I can replace all of the hoses, the radiator and the water pump on this car in less tha an hour, but it stilltakes me several attempts and several hours to get the air out of the system.

[bostogrun]

I always put my e36s up on Rhino Ramps when I bleed them. I found the the extra eight inches of lift tends to make the job easier.

Put a pan under the expansion tank. Take the cap off the tank. Loosen that little plastic screw right in front of the expansion tank and pour the coolant in. Watch it flow out around the plastic screw. When you quit seeing bubbles and pure coolant flows out, now tighten the plastic screw. The expansion tank will be overly filled but don't worry it blow out the excess through the overfill.

I think you should also make sure the heater is open.