All You Coolant Majors

[240Kuminachu]

Yes, Im sorry another Cooling problem. This one seems a little tougher tho, see if you can help me out. (skip down if you like to the indent)

This is prety cool out side temps, say 60-70, with rain, so its cool, not hot.

My car started over heating a few weeks ago, I've had the car almost a year with no problems, without an electric fan. So it over heats in town and strangely on the freeway. So I flush the coolent system and start over thinkin it was an air pocket or something blocking the way. Still happened. Hooked up an electric fan. still happened, So I took out the thermostat thinking it was bad. Still happened.

Ok, so, the other night I took a drive to moscow, it over heated real quick, this was at 9pm on a cold night. Pulled over and let it cool down and take off again, overheated again, so I pull the cap off and let it run while I fill it back up with the electric fan on, I ccheck the temp and its at like 140F, wich is hella cold, and its setting still, so i drive it with no cap till it boils all the coolent away and over heats again, so I full it up while its runnig, put the cap on and I drive all the way to moscow (80 miles) and the temp was 131-149 the entire time.

I dont know whats going on with her, Every time the car runs cool, and normal it does fine, but when I turn it off and let it cool and drive it again it over heats. I have to take off the cap, let it idle and fill it up every time I drive it or it over heats very quickly.

So, its not a fan problemIt doenst make sence that its the pump because it works fine if I take off the capITs not the thermostat cause I took it out. The rad is stock but in great shape, no leaks, I flushed it to make sure it was clear.I dont think its the cap on the rad.Heater works fine. so the hoses arnt backwards. Im using the stock temp gauge and my SDS temp gauge, the sds is relevant to the stock, so im sure Im getting corect numbers.Coolent and steam comes out of hoses under the intake manny when presure builds up. (heater hose connections)

It seems as tho there are pockets of air forming some how when I turn the car off and let it cool off. Then it over heats unless I take the cap off and let it run..

I duno, IM stumped on this one. I've never seen a car do this before. Sorry about the long post. Thank you!

[Def]

Are you sure you don't have any leaks in the system? I had a hose clamp loosen up on me with my M3 and it caused the thing to overheat QUICK because it couldn't hold pressure and wasn't letting the coolant "make the circuit."

If the system warms up a bit(only a bit), does it hold pressure? Take off the rad cap after the engine has been idling from cold for maybe 1-2 minutes, if there is a hiss from pressure being released the system is holding pressure. If not you are in trouble.

Another thing that is stumping me is where is all that coolant going? If you keep having to add coolant, obviously it is going SOMEWHERE. Is your headgasket blown? Any sweet/white smoke at idle or under load?

There is somewhere that the coolant is going, find that and I think you find the source of your problem.

[240Kuminachu]

I was confuesd *** well, but when it gets hot. like 230 or so it leaks out the heater hoses under the intake manny, coolant or steam if theres water in her, but thats only when it gets real hot, its holding pressure and there are no leaks, like drips. And no leaks or hissing at normal operating temps when it sits and idles fine. . THe reason I 've been able to keep putting collent in is because it keeps getting real hot and turning it into steam I think.. I dont think its the head gasket, its a brand new rebuild, no fade in power or odd noised, I check very thouroughly around the head and there are no leaks at all. . So I duno.. keep the ideas coming please.

[goldollar]

Have you tried to burp the cooling system and if you have can you give me some details on how you did it. I sounds like you do have an air pocket trapped in the system but a good burp should do the trick, also have you checked the water pump?

[240Kuminachu]

It did give a few good burps, I poured water in the rad while the car was running and very hot, spewed water and steam everywhere. After it does that it runs fine. Then I shut it off, let it cool. And next time I drive it, it does the same thing and over heats.

Im messing around with it alot today and trying different things. Thanks for all your help!

[240Kuminachu]

I think the water pump is fine, once I get the air out of the system it runs very cool, I got it to run at 95 degrees F today. It seems as though air gets in the system after it cools down somehow.

[87kevin]

Are you using a copper head gasket? If not, I hate to say it, but it's probably a blown head gasket. When cool, your engine is leaking coolant, but once it warms up, the leak is sealed, thats why it runs fine until you park it over night and your system loses pressure and collects air pockets. And BTW - dont rely on the SDS gauge, I made that mistake before - it reads 30~40f colder than your coolant really is.

[240Kuminachu]

Im gona take off the intake manny and check things out tomorow. So if the sds gauge isnt accurate than my stock gauge in the dash isnt accurate either? They seem prety close to eachother as the car warms up..

THanks for the help guys.

[scruffy63]

hey before you do that I had the exact same problems car kept overheating no matter what I did, And I was losing coolant also. It turned out the gasket on my water pump blew so you should check that just to make sure.if it is it just make sure you use liquid gasket.