Engine overheating

How do I do a leak down test?

Also the car runs beautifully there is no water in the oil?

Also, how do you bleed air out with it no running?

I don’t have a air system in my garage so I purchased one of those kits with the blue fluid and ran that test on my radiator and the fluid remained blue indicating no gasket leak. I replaced also the water pump, and then entire gauge assembly in the dash which included the temp gauge! I don’t understand a few weeks ago when I installed the new computer everything worked properly! We put the computer in and drove around and came back to garage open hood and the fans kicked on properly! Then the next day I drove to town came back to garage then the fans would not come on! I have a bad feeling something caused the computer not to work the next day after computer work everything properly the day before. Guess I might be purchasing an expensive scanning computer next and see if it will tell me if computers got shorted out? Any ideas I have replaced everything!

Roy, the car purrs like a kitten! Some of my mechanics friends said the car would run rough if it was head gasket. Also, if you have a blown head gasket the fans would still come on but the car would overheat regardless! The diagrams you sent me are useless since I have 3 wires on my ECT sensor, a solid green that tests 12 vts when on and the yellow that’s 4.99 vts and a orange/black stripe that I assume is a ground but I’m not sure. Can you find a wiring diagram of the 3 wire ECT sensor and send it?

I understand, but if the engine is hot because of a blown head gasket the fans should come on! The mechanical problem of the gasket being bad should not effect the electrical temp system! Also, it does not seem like this engine is really overheating when it is registering very hot like 250 or so. If it is a head gasket and the car is truly hot the fans should come on.

Do I allow the car to warm up or do I perform this test cold or does it matter? I am here in garage ready to start the key on sensor unplugged test.

Okay, I unplugged the CTS and turn key on and they did not come on. But I started the car and they came on in a few seconds after I started it! So what’s the verdict?

If the intake gaskets are bad then why did the new computer I installed work the system properly the first time I drove after changing computers then the next day it went back to this problem! If this Is a head gasket or intake manifold gasket the problem would not have disappeared for a day then return?

You told me in our discussions that the position of the sensor is important what does that mean? Did I have to get the new sensor tight in the exact position as the old one was?

So you’re saying it is intake manifold gaskets or head gaskets?

Okay, I changed the radiator and CTS I bled the air and the fans would not come on? My wife found on the Internet that after that the only thing left was the computer so I changed the computer and everything worked properly. If it’s an air pocket at the sensor then why did it work right after I changed the computer. The air pocket would still have been there? I didn’t touch anything else just changed the computer the air pocket should have still been there.