Blew coolant, overheated, white smoke, but good compression

[eburrows]

Hey All, the other day I was driving up a hill when I thought I heard some odd noises, but wasn't sure, then noticed the temperature idiot light. I pulled over, let it cool down a bit, then filled up with water, and started it up. It ran fine, but after about a minute, coolant and gas shot out of the coolant tank, and white smoke was coming out of the exhaust (warm, so. cal. day). I had it towed home and just pulled the plugs and checked compression: all about 150psi. Prior to this it was not consuming oil or coolant.

I assumed a head gasket failure, but maybe not? Any ideas what I should trouble-shoot next?

 

[DarylJ]

Coolant doesn't get into exhaust nor does the cooling system get pressurized with exhaust gases to make it shoot out any other way then a cracked head, cracked block or a bad head gasket.

I wouldn't bother troubleshooting any further, just pulling heads and carefully inspecting while hoping it's just the head gasket(s). The cylinder(s) where it's leaking will be steam cleaned and the rest will not. Look very very carefully around those areas.

 

[terryjm1]

You will want to get the heads resurfaced anyway. So, when you take them in for that have them checked for cracks. Cracks can be hard to see. I worked in an automotive machine shop many years ago. One of my jobs was checking heads for cracks. Aluminum heads were die checked. I often was quite surprised where cracks showed up.

More than likely you have a blown head gasket and as explained above the clean cylinder should help you locate the spot where the gasket gave up.

Also look very closely at the cylinder liners for any possible movement.

 

[eburrows]

I put it all back together, filled up the coolant with water, idled for a while fine, then drove around a bit. Drives fine, but starts rough and lost about a quarter inch of coolant from the reservoir in 20 mins of driving, including a little uphill.

Thanks for the feedback Dary and Terry. Looks like a full tear-down is in my future (again...).

 

[DarylJ]

Thanks for the feedback Dary and Terry. Looks like a full tear-down is in my future (again...).

We're all somewhere in between head gasket jobs