Been a long time since I posted and I've been going through old threads to find my problem.

My 05 z has a powerlab turbo kit and it has 37k on it. The problem is the overflow tank overflows when it gets up to temp. No overheating, no oil in coolant, no coolant in oil, no white or sweet smell in exhaust. When car cools what is in the tank gets sucked back in. The best I have found on here is new radiator cap with higher pressure instead of 13 psi. Ordered new cap with 18 psi. Or worst case head gasket starting to go. When I had a head gaskets blow before very noticeable signs white smoke etc. If so I have garage project ahead.

Going to make sure the air is all out of the system. Don't know if air in system would give these symptoms. Lower radiator hose gets hot so thermostat seems fine. Radiator hoses are not hard as a rock as if full of pressure.

Any thoughts or recommendations?

 

It also does this if you over fill the overflow tank.

How much is in the tank when cold?

 

+1

Fill up the block and the radiator...burp it and leave the overflow empty...go from there...

 

Did this start recently after the kit was installed? Air pockets in these cars can be a pain in the ***.

When the car is fully warmed up and everything is flowing the hoses shouldn't be spongy.

 

No kit has been on for about 5 years. The overflow tank will overflow then when it cools all coolant is sucked back in radiator. Tank is empty. I have been adding some to reservoir enough to reach lowest mark. I'm going to try to see if any air is in system tried the valve on the heater hose but same situation. Guess I will run car up on ramps and try the radiator to burp it and wait for new radiator cap. I can squeeze the hoses they aren't spongy just not rock hard like I thought if system is getting over pressurized.

Thanks for ideas and suggestions.

 

^^^A new cap and raising the front to burp it good, Is a great start. Let us know how it goes.

 

Don't like when people don't tell outcome.

Raised front end and did my best to get air out of system yesterday and new 18psi radiator cap came. Also changed oil to make sure it looked okay. Wife drove it to work today about 60 miles total and everything looks good. Coolant raised about 10mm in resevoir and that was it.

So all looks good for now. Thanks for the help!