Cooling problem. Need Help! - BMW Forum

Kr320i · 10-29-2007, 05:34 PM

I have a 1981 320i. I've replaced the radiator because of a leak and replaced all of the hoses. Didn't have a overheating problem prior to this. The thermostat wasn't replaced. I can see the water flow while the engine is running but I don't know if the flow I see is sufficient.

Any Ideas?

Thanks!

AlpineSixAndSeven · 10-29-2007, 05:36 PM

Quote:

Originally Posted by Kr320i

I have a 1981 320i. I've replaced the radiator because of a leak and replaced all of the hoses. Didn't have a overheating problem prior to this. The thermostat wasn't replaced. I can see the water flow while the engine is running but I don't know if the flow I see is sufficient.

Any Ideas?

Thanks!

replace the thermostat it might be stuck closed

Kr320i · 10-29-2007, 10:31 PM

Thanks so much for the reply. I've ordered the thermostat and will install it tomorrow.

AlpineSixAndSeven · 10-30-2007, 02:55 PM

cool glad to help i think of anything it could be but i thing that is it beside the waterpump?

Kr320i · 10-30-2007, 04:31 PM

Hey Fade M, I replaced the thermostat and the new thermostat didn't open at all. I put the old one back and I can see the water flow beautifully. I boiled both therms to see what temp they opened at and the new didn't open until almost 200 degrees. Not good. The old one opened at around 140 to 150 degs.

My question to you is ...since I replaced the radiator and drained the coolant completely...could there be an air pocket trapped in the engine block causing the overheating? Also, have you heard anything about bleeding the engine block from some bolts on the freeze plug side of the block?

Thanks in advance.

AlpineSixAndSeven · 10-30-2007, 04:40 PM

Quote:

Originally Posted by Kr320i

Hey Fade M, I replaced the thermostat and the new thermostat didn't open at all. I put the old one back and I can see the water flow beautifully. I boiled both therms to see what temp they opened at and the new didn't open until almost 200 degrees. Not good. The old one opened at around 140 to 150 degs.

My question to you is ...since I replaced the radiator and drained the coolant completely...could there be an air pocket trapped in the engine block causing the overheating? Also, have you heard anything about bleeding the engine block from some bolts on the freeze plug side of the block?

Thanks in advance.

never hear of that just make sure the heat is on FULL and you burp the upper radiator hose by squeezing it while the car is running.

how fast is it over heating?

Kr320i · 10-30-2007, 05:06 PM

It overheats pretty fast. It's at 1/4 on the temp gauge one minute and the next it's jumping to half and higher. The flow from the water pumps seems to be ample for normal operation but I'm not sure. I compare to american cars and it seems consistent.

Thanks!

AlpineSixAndSeven · 10-30-2007, 06:07 PM

is there any play in the water pump shaft but mostlikely water is not getting to the radiator/ or back i dont know this car to well try it with out the thermostate at all if it over heats it is a more serious issue try that though it shouldn't get to operating temp and are you using coolant and water 50/50 to 60/40(60 coolant)?

bimmerguy82 · 10-31-2007, 09:12 AM

KR320- it sounds like since you've replaced your coolant system & you are probably having an air pocket issue. The best way i have found to bleed bmw's is to park it facing slightly uphill so the nose of the car is the highest point and just burp it until it's good. That means full heat on your climate control.
Also there are two different temp. settings you can buy for thermostat. typically they are set for 200 F, but if you live in a cold climate or just want yours to open sooner they have some that open at 180 F.

Also, you can buy some stuff called Water Wetter made by Redline I think. I've used it and it works good. It's just an additive that lubricates the thermostat and keeps the coolant 5-8 degrees cooler.

BMWJNKY · 10-31-2007, 12:11 PM

What coolant to water mix did you use? Too much coolant in the mix will cause the engine to run warm. If the mix is 50/50 or less of coolant I would guess that you have an air pocket in the engine. Let the car idle with the heater on but do not rev the engine, just let it idle. Keep an eye on the temp gauge but as long as it doesn't go over 3/4 you should be ok. Once the air is out of the system the car should run right around the 1/2 mark.

AlpineSixAndSeven · 10-31-2007, 02:35 PM

yeah the water wetter workes good

Kr320i · 10-31-2007, 02:47 PM

Thanks guys for the advice. I'll give it a shot.

BMWJNKY · 11-01-2007, 01:50 PM

I would not put Water Wetter in the system untill the overheating issue is fixed. Water Wetter only helps in a system that is working properly, not a fix for overheating.

gotKRAUT · 11-01-2007, 03:20 PM

and make sure all your hoses are connected before adding water wetter...true story...

AlpineSixAndSeven · 11-01-2007, 03:22 PM

OMG i want a pic of your cars together it would be "Cute"