warrenb213

K guys, I am really lost at the moment. I've had this wierd overheating problem through the last two years and I'm really beginning to lose my mind over it.

Through the winter, the car doesn't have much of an issue at all. Through the entire winter season there is one time that I recall having to refill my radiator.

But, last summer and now the beginning of this summer the problem is wreaking havoc.

So to explain the problem:
The overflow tank fills up to the lid and begins to spew. As it raises bubbles enter the overflow tank. The engine doesn't suck back in any of the coolant once it's in the overflow. It bubbles so much that the coolant system gets to the point of being almost bone dry and begins to overheat. Once the radiator fan kicks in the bubbling stops. Then the fan goes off, bubbling comes back.

I let the car sit at idle for over 2 hours and no bubbles will appear and it doesn't raise the level of the overflow tank. But, upon driving for a bit the bubbles come back and the overflow tank level rises again.

The first thing I notice is my automatic transmission as it shifts. Upon me refilling the radiator, my tranny shifts perfect. But, then I notice the shifts getting very laggish. That is when I know for sure that the overflow tank level is rising and the bubbles are back. It's a correlation I have gotten used to and at that time, I let the car cool a bit, pop the rad cap, and refill.

During the winter this happened to me only once, in exception of that one time during the winter my shifts were fine and the coolant level stayed good. In fact, as the days here have gotten hot again, the tranny starts shifting funky, I catch it before it spew's from the overflow, refill the radiator with whats in the bottle and end up with the coolant level in the bottle I began with. So the rules out the entire burning off someplace or leaking someplace?

I have done a couple things to try and resolve the problem:
1. Changed the thermostat
2. Changed the rad cap

I have also had a full flush of my coolant system done as well.

There is no white smoke out my tail pipe ever, there is no milkshake in my oil, there is no oil in my coolant. So I think that rules out the head gasket? I mean ----, over two years I'd of thought a head gasket would have gotten worse?

The water pump works, and was changed less than 40k miles ago.

Anyone have any idea of what this could be? Also, another thing to add is that my fan DOES kick it, but to my remembrance when the engine was extremely hot the fan would engage even with the car completely turned off? Are the fan's on D16y7 radiators 1 speed, 2 speed, 3 speed? I'm curious if maybe the fan has these different levels and somewhere along my ownership of the car the switch went faulty?

gen4acclude

hydrocarbon test ftw

warrenb213

i dunno if it means anything, i passed emissions at the end of April? lol

losesomethinbra

If the engine oil has water in it and vice versa, you're right, thats a sure sign of headgasket failure... But it doesnt always happen that way. It could be hot air from the combustion chamber at a hair line leak headed straight into the coolant causing it to boil nearly instantly and that pressurizes your coolant past the freakin 12lb or whatever radiator cap you have and into the overflow. If its a small enough leak it might only do it under load. Forget the transmission just fix the overheating and worry about that later.. Also if you are moving, forget the fan, it doesnt need to be on anyways so that cant be it... So do a compression test or leakdown! GL mang