Head gasket blown?

[69red]

I'm guessing that my head gasket is leaking:

radiator pressures up in 1 to 2 minutes with motor cold
coolant is foamy when hot
But oil is clear and clean

Is there anything else it could be that I should check before I start pulling it apart??:?

 

[Skiddy]

Pull the radiator cap off when it's running and see if it makes bubbles.

 

[Broncobowsher]

Do a leak down test with the rad cap removed. When you see water start to rise or bubble, then you know what holes(s) are leaking.

 

[69red]

Thanks for getting back guys.

I haven't seen bubbles exactly, but after running it for a while and getting it up to temp(190+), let it cool down then take off the cap there is foam on top of the coolant.

when I start it cold the level does rise after a while, then starts to spill so I put the cap on. About a minute after putting the cap on, the upper rad hose is cold, but pressured-up hard. at this point the block is still cool to the touch.

when you say "holes" do you mean cylinders? more on the leak-down test please.

thanks.

 

[A&Mbronco]

compression test

 

[Broncobowsher]

Hole is a cylinder. Sorry the slang slipped out.

Leak down test. Using a compressor, apply air pressure to the cylinder with the valves closed (TDC firing stroke). This is usually a tool for determining the engines condition by checking rings and valves. But it also works in checking head gaskets.

From the description the leak is minor. A compression test won't show anything as the cylinders only recieve a quick puff of pressure as they come up on compression. In this case a leak down test is much better as you can leave pressure on the cylinder and gasket for as long as the compressor can keep up.

 

[69red]

Great,
I'll try that this weekend.

is there anything else it could be? I can't think of any other process in the motor that would pressure up the cooling system when it is cold, so it has to be a bad gasket; a cracked head/block would be leaking water into the oil.

 

[wildbill]

You can go to a good rad. shop and get a test strip and it will tell if you have a leak into the water (head gaskit) its a easy ck. and fun to fix good luck. Bill