vteckiller

iTrader: (3)

So my car was a v6 then i put a first gen sbc in it. It was freshly rebuilt and now it overheats. So far i have gotten a smaller water pump pulley, new 2" thick be cool radiator, new fan, new thermostat, and i put in a new water pump when i built it. I ran it and got all the bubbles out of the coolant. There isnt white smoke coming from my exhaust....could it be a blown head gasket without white smoke?? What else should i try?!

LS1Z28_98

It's not a bad temp sender is it? That begs the question....are you using the gauge on the cluster or an aftermarket gauge? If it's the gauge on the cluster....how did you integrate it through the PCM and all?

vteckiller

iTrader: (3)

its got a brand new mechanical autometer temp gauge. so thats not it....

SOMbitch

iTrader: (8)

Does the motor smell or feel hot? Get a temp gun and shoot the temp sender and see what you get... should be 5* of the guage.....

If you are losing coolant it is a HG...

vteckiller

iTrader: (3)

the engine definately hot. the radiator is extremly hot when i pop the hood and you can feel the heat. could it be a hg without white smoke?

SOMbitch

iTrader: (8)

Are you losing coolant???

thirdimpact

Did you put the intake on, or did whoever rebuilt it put it on?

vteckiller

iTrader: (3)

i havent lost enough coolant to notice anything. but i dont drive it that much because it overheats. and I put the intake on.

crainholio

iTrader: (2)

Rent a cooling system pressure tester from AutoZone, costs nothing when you return it.

It installs in place of your radiator cap, you pump it up to 16psi or whatever your cap pressure is, and then see how long it holds pressure.

It should hold for over an hour easily, but a bad head gasket or other failure will cause an immediate pressure dropoff as soon as you stop pumping it and you'll see that on the tester's gauge.

Let us know what you find.

crainholio

iTrader: (2)

Also, does it overheat while standing still idling, or while driving?

vteckiller

iTrader: (3)

Ok itll get to like 230 degrees and then ill stop and let it idle but the needle keeps climbing even at idle.. There is no autozone in my town will like a napa have that test also?

SOMbitch

iTrader: (8)

Yep do this and if it is losing pressure look for leaks. External should be obvious leaking and HG may leak but be internal....

crainholio

iTrader: (2)

If the local NAPA doesn't have it, they can usually get it.

thirdimpact

Its possible you put the intake gaskets on backwards, the older small blocks should have a restrictions in the rear coolant passages. If you flip them and the restrictions in the front passages you cant flow enough coolant because the thermostat is also a restriction. I have seen this on a few small blocks that had been either rebuilt or had a new intake put on. There could be tags on the gaskets that stick out between the intake and cylinder head if they are at the front they should be on correctly. If your gaskets didn't have these restrictions then it doesn't matter.