Fresh Rebuild overheating

[okm12346]

So it was fine during the cooler months, but now every time its above 80 degrees it starts overheating. I add coolant and it pushes it out little by little thru the overflow tank hose. The coolant overflow is full, but it doesnt get sucked in when the system needs it.

Dont have OEM thermostat, but its still the 190 degrees one. The water pump is GMB brand and it has less that 5k miles. Fans dont kick in all the time since it gets low on coolant

I did a little searching and i found that timing being retarded might have something to do with this problem

Any advice is appreciated

 

[92AWDHX40]

Overheating do a compression test i would start there regardless of how fresh the build is.

 

[cwriley]

definately do a compression test, possible head gasket.

 

[frosh29]

A little more info would be nice. Let me ask you this... are you boosting the car when you notice that the coolant is missing? Does it still happen when you baby the car?

I had a dsm that was pushing coolant into the overflow only while boosting. It was also burning coolant in the cylinder chamber, caused by a bad (stock) headgasket. I have gone metal and will never go back.

-Scott

 

[Xit40]

How's the overall health of your cooling system? I know you said you had a new water pump and thermostat, but how does your radiator and radiator cap look? Is it still the stock one from the early/mid 90's? Missing/bent fins? Is there any funny crud in your coolant? Does air flow freely thru the fins on your radiator or are there 5 million other things in front of it (intercooler, oil coolor, etc.)? The more information you can supply us with the easier it'll be to solve the problem

 

[kahl23]

I had a similar issue with my old head and an OEM metal head gasket. It would push coolant no matter what under boost, turned out the head was warped. A quick and dirty way to test this is by emptying the overflow tank and then going for a ride without getting into boost, then checking the amount of coolant, if any you pushed. Empty the tank and then go on the same route, but this time get into boost. If you have more coolant the second time, or coolant the second time and not the first, you're pushing coolant under boost.

 

[canada4g63]

I would start off with a compression test.

 

[blackGSX2g]

Typical signs of a blown headgasket. Pick up a 'block tester' from an auto parts store and follow the directions in the kit. It tests your cooling system for the presence of hydro carbons from the exhaust. I've gone through my fair share of headgaskets and all have had perfect compression with no visable smoke out of the exhaust. The block tester revealed the problem every time.

 

[greekgodchaos]

In addition to all previous posts, you might want to look into hard wiring your fans either to a switch or your 12v ACC wire to make sure your fans are doing their job all the time.