Overheating

[rtrfamjr2]

I am having a problem with my BMW 325i overheating.

While driving above 80 kilometers it has no problem for about two hours then the coolant is empty. When stopped it quickly goes to the red. Having a problem with over heating. with a 325 I BMW.

The car runs great on the autobahn or driving above 80 Kilometers it stays in normal heating range. While stopped or driving below 80 it quickly goes into the red.

I have refilled the coolant and as soon as I drive 5 kilometers it is empty. I noticed while parked and letting the engine run that it was dripping from a valve that was connected behind the fan on the fan assembly.

Any clue

Any ideas. I am thinking that maybe the fuse or hermastat is out. The fan turns, but its not circulating the coolant.

 

[Lowen]

Is your oil "milky" looking at all? I know you don't want to hear this, but sounds like a cracked head or a bad head gasket.

 

[rtrfamjr2]

replt is oil milky

The oil isn't milky. WHen looked at, the coolant was coming out right behind the belts just behind the fan arm.

 

[Rukus]

What does your exhaust look like?
but, more reassuringly,
Maybe your pump is shot, check it out.

 

[Lowen]

...the coolant was coming out right behind the belts just behind the fan arm...

Waterpump is most likely shot (90% sure of it). When replacing the waterpump also replace the thermostat.

 

[Custom 3]

I think rukus is on to your problem. I've recently dealt with this kind of problem (sadly I wish it were on someone else's car )

When I recently replaced my drive belt (timing belt) and tensioner, also replaced my water pump. BMW recommends that you replace the water pump every 2 drive belt changes...better to do it everytime just to be safe. Water pumps aren't that expensive and it can save you a lot of heartache and work later on.

About 1000 miles later the gasket (made of paper) failed...and I was left stranded in the middle of nowhere.

BMW is aware of another potential problem with your water pump...the main seal on the front pulley that attaches to the fan can go bad.

Here's the easiest way to check and discover the culprit of your overheating. While the car is parked on level ground, fill the system with water and allow it to sit for a couple of minute. Watch the engine bay and the ground underneath closely. If you see a trickle of water, locate the source. If you see nothing, go ahead and start the car and watch a little more. If your coolant is emptying that quickly, you're going to see fluid coming from somewhere.

As for the main seal on the water pump, if this seal is bad...you will need to purchase a new water pump. There's no way around that. If the water/coolant is coming from around the sides of the pump, your gasket has failed and it will be a cheap fix (about $2 US for the gasket and a couple more for some gasket seal compund).

As always...if it's been more than 50-60K miles (83500-10000 kilometers) since you last drivebelt change, you'll want to change that while you're in there, since you'll have to remove it anyway.

HTH!

- Jason

http://www.custom3.com

3 Series Performance Specialists!

 

[pogiboy9]

Hmmm Custom, I might have a questiona bout this too because my car is overheating also, but both sitting and running, overheating around .. 3/4 the mark. We checked it, and its cause the front fan(s) don't go on, i'm not master mechanic i'm very much newb, but my dad is master mechanic. But better to know more options from other experiences than to be sorry, hopefully you get my email and ma ybe give me a call. thnx

 

[rtrfamjr2]

thank you

thank you all for your help. the water pump was the problem. To bad a didn't ask about bleeding the coolant system. My fault. Thanks

 

[ODDferkOUT]

I was about to say it was your waterpump. That happened to me a month ago. I went to my brothers work and all the coolant leaked out from under my car. As for my temp, I have a faulty temp gauge, so I never know if my car is overheating or not.

 

[Ben]

the most important guage on the car is the temp guage. if all the guages went out that would be the first one i would replace.