Nissan Repair: Overheating problem, head gasket, compression test

Question
QUESTION: when we received the car, there was no thermostat, still the same problem....i have idea it is the head gasket.  we will have to open and redo.. thanks for your advise...

ANSWER: HI Michelle -

Actually I was going to say if there is no thermostat, that might be the reason it overheats. The thermostat not only controls the temp at which it opens to allow the water to cool, but also restricts the flow a bit so the water can remain in the radiator longer to cool more efficiently. By removing the thermostat, the water flows too quickly through the radiator, not getting a chance to cool, and picks up even more heat when going through the engine while in the loop, thus raising the temp slowly, especially in stop and go traffic.

As far as the head gasket, unless you have bad compression, it is probably not the problem. Try taking a compression test before condemning the gasket.

Just trying to save you (a lot of) extra work and some $$$.

Hope this helps
Aloha
calvin

---------- FOLLOW-UP ----------

QUESTION: Compression test it shell be. Now, say it is not the gasket and the compression test is fine. What else can the problem be? lets recap: replaced the thermostat, water pump. Flushed engine and radiator. Checked oil for water(neg), water level does not drop...any more ideas? I will let you know about the compression test..tx

Answer
Hi Michelle -

I would double check that radiator, especially the bottom part of the core to see if there is restriction. I worked on a car before that had very clear water when you look into the radiator, but when you remove the petcock on the bottom to drain, nothing would come out because it was clogged with rust and debris. Even if you use pressure assisted flushing, it may still not unclog.

Might want to check that.

Thanks
calvin