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BustedE36 11-18-2012 01:29 PM

Cooling problems -_- please help.
Hey all i've had cooling problems with my e36 since i got it..water pump failed resulting in a blown head gasket, which i replaced and milled the head and what not..anyways i did the head gasket right..replaced water pump, thermostat, and radiator all within the last 5k miles. So now heres my dilemma. when i get up to operating temperate my upper right hose will have allot of pressure and be very hot, while the lower hose is i open the bleeder valve to relieve pressure and the heat will start working in the cab for a good amount of time until i come to a stop and idle...sometimes it will start to go over operating i will pull over and relive pressure, then it goes back to operating temp and is ok..but it seems like i am at a never ending battle with air in my now heres the weird thing to me..while the coolant coming out of the bleeder screw is hot..the expansion tank coolant is still ice cold and has barley any pressure at times, i really don't want it to overheat and blow the head gasket again, someone please tell me what is going on!

Thanks for your time!!

TheFinanceGuy 11-18-2012 03:49 PM

Bleed it again... Raise the front of the car up. Sounds like an air pocket not allowing the coolant to flow.
Or a blocked passage way.

BustedE36 11-19-2012 10:21 AM

Okay ive bled it before but ill do it again just to be sure,

when you say blocked passage, what could be blocking it?

Another question on a side note..when my car overheated and blew the headgasket, could the thermostat housing ( Aluminum ) be warped and keep the thermostat from opening?

Thanks for the speedy reply, this is my DD and i need all the advice possible!

veteran011 11-20-2012 12:29 PM

did you not replace the thermostat and housing when you did the water pump?

BustedE36 11-20-2012 02:19 PM

i replaced thermostat yes, but not housing, thats kinda what i was asking..would that be keeping the thermo closed and not letting fluid flow freely?

veteran011 11-21-2012 06:47 AM

i dont think thats very likely but its a possibility. think the only way to test it is to pull the thermostat and put it in a pot of water and heat it up until you see it pop open. then measure the temp of the water. depending on teh thermostat it could be 88degC or 93degC.

dc_wright 11-21-2012 07:45 AM


Originally Posted by BustedE36 (Post 7205606)
i replaced thermostat yes, but not housing, thats kinda what i was asking..would that be keeping the thermo closed and not letting fluid flow freely?

I'm struggling to see any way the TStat housing could be warped enough to interfere with the Tstat and not be immediately visible as well as leaking coolant. This may seem like a silly question but I have to ask, could you have installed the Tstat backwards? It's been done before.....

BustedE36 11-21-2012 09:56 AM

Thanks for the info, and not backwards , I've been bleeding the air out alot and it has not over heated, but blows cold air when I come to a stop,

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dc_wright 11-21-2012 10:49 AM

Don't know what bleeding procedure you're using but this one has always worked for me. You have to add the coolant VERY slowly and let it keep overflowing until there are no bubbles, not even tiny ones coming out of the bleed screw hole. As the DIY states do not do this with the engine running. Also make certain all your heat controls are set to the highest setting, both the temp control and the cool/heat control.

arkie49 11-21-2012 03:20 PM

just some thoughts,very rare but i have some pumps with defective impeller,double check belt routing,back to basics did u put correct side of head gasket up marked top,some shops have special machine to eliminate air pockets,i would try to find one to do this procedure first if ur still having trouble,put a post up if u solve problem,good luck

BustedE36 11-25-2012 03:02 PM

Okay so it takes two people to bleed my system properly, so I empyted the system, drained the block. Then filled up the resivor while person #2 started the car and held the throttle at 2k-2.5k RPM. with heat and fan on full blast. As I continued to fill the resivor allot of bubbles came through the bleeder screw, took over an extra gallon of 50/50 mix to fully bleed it. . All in all make sure you have 2 gal antifreeze and 2 gal distilled in my case it took 3 gal of both, " air sucking wh*re imo" until the fluid from the bleeder screw was clear from bubbles. Now I get heat when I idle as well as driving.. works perf :D. Oh and front end was jacked up about a foot.

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hornhospital 11-25-2012 03:06 PM

There ya go! :thumbup: It's simple when you follow directions.

dc_wright 11-25-2012 03:45 PM


Originally Posted by BustedE36 (Post 7213576)
person #2 started the car and held the throttle at 2k-2.5k RPM.

This is why you needed so much extra coolant. When you run the engine while you are bleeding, the water pump aerates the coolant when the system is partially filled and then it takes a lot more coolant to bleed out the mixed in air.
Everyone thinks you have to run the engine to open the thermostat to get the system bled but the thermostats come with either a small bleed hole or a dimple in the valve to allow air to bleed by. This is why the thermostat has an orientation arrow so that you install it with the bleed vent at the top. That's why you have to add the coolant very, very, very slowly.

BustedE36 11-25-2012 06:38 PM

Every time I've done it with the car off air stays in the system.. as it seems unnecessary.. its the only method that worked for me.

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