I was doing the 30k mile maintenance last weekend. Everything went fine except the radiator flush. Well, at the time it seemed to go fine, but now I notice my heat is not nearly as hot as before. Can anyone explain this? I opened the heater air release valve as stated in the shop manual when filling it. I've driven the car and then checked the fluid level 6 or 7 times now. It moved down ever so slightly, <1/2 cup, a few times. Any idea what could cause this?

 

There is an air bubble in one of the hoses going to the heater core. Same thing happened to me when I removed the upper water pipe to install my headers. There is an air bleeder hole on the heater hose back by the battery, have you tried opening that to let air escape?

Andrew

 

Yep, its an air bubble. Here's the solution I found that works very well. On the firewall, towards the passenger side of the engine, you will see a heater hose with a plastic fitting in it. This is the air bleed. Once your car is COMPLETELY cool, remove the plug with a large phillips head screwdriver. Place a rag under the hose to catch any drips. Using a very small funnel, slowly pour in some 50/50 coolant until it won't take any more.

After you close up the air bleed, drive the car as normal. You may have to repeat this cycle a few times. When I replaced my radiator, I had to do this step 4 times before I got good heat. Each time, the car would take a few more ounces of coolant in the back. Once the air is all out, your heater will be just fine.

 

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