overheating saga

[cousindave]

Ok, this is a continuing thread to" im ready to kill myself". I removed the brand new thermostat and ran the motor without it. Now I can run the engine with the radiator cap off and there is no pressurizing also both hose are same temp. Idling the engine results in the temp gauge reading just south of " N". I then rev the motor and the gauge rads in the red. I put a thermometer in the filler neck and temp is reading 135°F. Also when I rev the engine I can see the water circulating then I let off on the gas and the water rises and spills out of the radiator. I also notices some air bubbles like a very light froth that collects on the diameter of the filler neck. Could this be the head gasket?

[cousindave]

Almost forgot, no water in oil, no smoke out of the tailpipe and compression on 12&3 is 110. # 4 is ar 115. Than ks

[martindktm]

Have you tried without the thermostat and with the cap on to pressurize the system?

[cousindave]

Yes, and still overheats!

[I Leak Oil]

Run it with the cap on, let it build pressure. Shut it off and quickly remove the plugs. Listen to each cylinder for any hissing. Do a leakdown test. Cap on cap off.

[cousindave]

Ok, with a multimeter, I checked the wire that connects to temp sender. It reads 12.24/12.25 while engine is running and while gauge is near red. Should this read 10v? Or is 12.24 ok?

[cousindave]

I leakoil: I'm going to do that right now thanks!

[martindktm]

but 135F is not that high...It`s maybe only the gauge that is wrong..?

[cousindave]

That's what I think too. My only concern with the gauge is that the fuel gage is reading correctly and both gauges utilize the same regulator.
So if one gauge is false I am assuming both should read false. Am I correct?

[singingcamel]

Ok, this is a continuing thread to" im ready to kill myself". I removed the brand new thermostat and ran the motor without it. Now I can run the engine with the radiator cap off and there is no pressurizing also both hose are same temp. Idling the engine results in the temp gauge reading just south of " N". I then rev the motor and the gauge rads in the red. I put a thermometer in the filler neck and temp is reading 135°F. Also when I rev the engine I can see the water circulating then I let off on the gas and the water rises and spills out of the radiator. I also notices some air bubbles like a very light froth that collects on the diameter of the filler neck. Could this be the head gasket?
Whats the condition of your radiator?

[martindktm]

No because they have different sending unit. And they are different gauge too. They only share the same voltage regulator.

[cousindave]

Singingcamel: I just flushed system on friday and radiator looks clean. Also flush engine block and heater core. Also radiator is flowing nicely.

[martindktm]

It may be just the gauge. I had an Audi 5000S that had the same trouble many many years ago. Just a fauty gauge. If you were going up to 180-190F I would look elsewhere but at 135...

[albersj51]

I agree, the culprit may be your gauge. 135F is 57C so your stat shouldnt even be open. An 82C stat should open around 180F.

[cousindave]

Thanks everyone! Now, how do I go about testing the gauge?

[martindktm]

Juste change it, including the sending unit.