1998 BMW Z3 Overheating

[Al Sykes]

I have a 1998 BMW Z3 with 2.8 engine. Was running fine till the radiator return hose came off. I replaced the hose, added 50/50, bleed the system with heater on high. Now it is overheating. I have very little warm air coming out when the heater is on high. The radiator is fairly new.
I just tried bleeding it again. Doesn't seem to be much water coming back through the radiator return line, even after reaching operating temp.

Update: I got the front of the car up in the air as suggested. Bleed the system again. Drove it for 10-15 minutes and it did not overheat. Before it would overheat in 5 minutes or so. Had very little warm air from the heater before but now it is very warm. Think this solved my problem. Thanks to All who had suggestions!!

 

[Stevo7682]

It sounds like it still has an air lock

 

[Al Sykes]

It sounds like it still has an air lock

Thanks

It sounds like it still has an air lock

Thanks! I'll try bleeding it again.

 

[colb]

Get the front of the car as high as possible and try bleeding it, sounds like air in there somewhere with little heat getting to the heater, make sure its set on hot when bleeding so there is a good flow through the heater matrix. If that fails I would start looking at the water pump. If you end up doing that I would also put in a new thermostat at the same time.

 

[Al Sykes]

Get the front of the car as high as possible and try bleeding it, sounds like air in there somewhere with little heat getting to the heater, make sure its set on hot when bleeding so there is a good flow through the heater matrix. If that fails I would start looking at the water pump. If you end up doing that I would also put in a new thermostat at the same time.

Thanks! I'll give that a try tomorrow.

 

[BMBabe]

@Mnbrennan
@Lee

 

[Mnbrennan]

Agreed with the above. Mine took an age to bleed properly, I had some real difficulty with it. I thought that bits had failed but there was just air in the system.

The lengths we go to for cars!

 

[Antm72]

Sounds like as said either an air lock or pump.
A stat stuck shut it would overheat, stuck open run cool.
I would do both personally whilst its apart not a big job

 

[Al Sykes]

Thanks! I'll give that a try tomorrow.

Hello
Thanks for all the ideas on my BMW Z3 overheating. I did as suggested, got the front of the car up high.
Bleed the system again. Drove it for about 10 minutes, ran fine and didn't overhear. Before it would overheat in less than five minutes.
The heater was not putting out hot air before but is now. Think that took care of my problem. Thanks to All again!

 

[t-tony]

That's what we're all here for Al. Welcome to the forum too. By the way, where are you located in the US please?

Tony.

 

[t-tony]

Agreed with the above. Mine took an age to bleed properly, I had some real difficulty with it. I thought that bits had failed but there was just air in the system.

The lengths we go to for cars! View attachment 66111

Never seen a Zed get the kiss of life before Martin, you the first aider at work.

Tony.

 

[Ianmc]

Never seen a Zed get the kiss of life before Martin, you the first aider at work.

Tony.

It must be experience of petrol tank syphoning with hose pipe coming into play