Coolant out exhaust???

[MitchP]

I have an 87 GL Wagon with 4x4, auto, and carbed. It currently is just a few miles shy of 160K. The car was loosing coolant and I spent the summer trying to track it down, until the water pump bearing failed. During that time, it did get overheated a couple times from low coolant.

With the new pump, everything was good again for a few days, then it started blowing steam out the tail pipe with a strong anti-freeze odor. The warmer the motor gets, the more it blows.

I did compression checks and everything was reading normal. I was assuming head gasket. I now have the motor on an engine stand in my garage, and completely disassembled.

I can see no problem with the gaskets or the block. There does "appear" to be a small crack in the heads between the valves, but it is common to all four cylinders and I'm unsure if this is normal or what?

What am I missing??? If not the head gaskets, where else could be suspect?

[Skip]

Mitch, you are correct about the small between the valves crack - normal and does not cause worry (unless a valve seat is in jepordy)

 

Where you want to look for the real problem is inside the exhaust port on the head, you will see a buldge, this is where the H20 jacket gets closest to the port.

Look for a small steam cleaned line, this is the crack.

 

The other place coolant can get into the comb chamb is via the intake manifold gaskets, how did they look?

[MitchP]

Well, I'm at a loss. I checked the heads inside the exhaust ports and everything looks OK. The intake gaskets look as though they were doing there job still. Anything else to look at?

[Ozsubie]

You may want to have a second look at the crack in between the valves. As Skip mentions, it doesn't usually cause problems, however sometimes these cracks can extend down deep into the head and may cause problems. I've just had the heads off my EA82T and a very innocent looking hairline crack between the valves actually extended nearly down to the valve guide. You could only see how far it actually went after the head shop cleaned up the head and put some sort of die in the crack to highlight how far it extended.

[rallyruss]

I have torn down motors that blew coolant out the exhaust only to be frustrated with lack of sollid evidince as to the source of the leak.

 

all previous comment are really good espically the intake gaskets. how clean are the pistons and valves? can you narow it down to one cyl.?

 

head gaskets can leak thru the middle of the gasket to the cyl. its really hard to see but it hapens.

 

have the heads pressure tested. if all is good put it back together and pressure test the cooling system for an extended time period. this can be done out of the car too if you want to make sure before droping it back in. requires a bit of creativity.

cheers:drunk:

[MitchP]

I guess this is just going to take more work than I thought. I spent a lot of time looking at the heads and cylinders. Everything looks normal. This is getting really frustrating, as I was hoping for a quick and easy repair. Mabey it's time to just look for a new motor or part the car out. Thanks for all the good info and I will check everything out again.