coolant not going into radiator

[bmwflier]

My '97 bmw 528i was overheating so i replaced: waterpump, fan clutch, and thermostat. I also removed all coolant prior to reassembly. Upon refilling coolant into the overflow reservoir it took less than one gallon. I followed directions in Bentley manual for adding coolant and was unable to get the coolant level to go down into the radiator.

The top radiator hose is warm, and the bottom hose is cold; after running the engine less than 5 minutes the engine overheated and heater is blowing out cool air. Seems like coolant is not getting into the radiator...any ideas??

[witeshark]

A lot of air is still trapped in the system; researching the cooling system bleed out procedures should help.

[brettski]

When the engine is cold, you might be able to get more coolant into the system quickly by removing the top radiator hose and pooring the coolant in that way. You do need to purge air out of the system by using the bleed valve between the radiator and expansion bottle. Good luck.

[marti5]

There is of course the other scenario...you've got the thermostat in the wrong way around, I have heard of this many times..

[bmwflier]

Thanks for the answers, umm yes the thermostat was in correctly, although I did check I used your method for adding coolant into the radiator, worked great But I did find that my coolant resevoir cap is leaking, so I will be replacing that before I go any further. Thanks again. I'll respond with results once I get them.

[bmwflier]

So I replaced the resevoir cap with a new one. Bled the air from the system as demonstrated, ran the engine up to warm. Then let the engine cool so I could add more coolant. There was no more room for coolant so I bled the air again and took car for a drive. It overheated within 3 minutes and still doesn't blow warm air from the vents.

Any other ideas anyone has, Im stumped

Thanks

Flier

[marti5]

You must have an air lock or the new water pump/ thermostat is duff....yes its new but can still be duff....no warm air so Im thinking thermo even if its new, if the top hose is hot/warm and the lower hose is cool/cold its the stat for sure.

[bmwflier]

Hey everyone, I decided to replace the thermostat even though it was new. While I was removing the shroud, I saw that the recovery hose that runs atop the radiator was kinked. I fixed the kink, replaced the thermostat and purged the system of air as instructed...and it's finally working. That is, it's not overheating and it's blowing hot air from the heater. Yea and a Big Thanks to all. These things look so impossible when you're in the middle of them and yet so simple when you look back. Oh yea, I prayed before I started this time too.

[marti5]

Good stuff...It had to be something simple.....

[Raymond Lee]

BMWflier
I am really glad you got it fixed! I can imagine how glad you are now.