Bad head gasket after overheat?

[bradfr]

I followed instructions on bleeding the system from this site about 3 times. I filled the system, took cap off, ran engine for about five mins and topped it off then put the cap back on. I also pulsed the hoses on the cooler to help burp the system.

There is no coolant getting into the oil system but there is oil getting into the coolant system. The only thing I noticed when tearing the head off is that there is an oil cooler as well. I didnt realize this initially. I guess that could be hurt as well.

The very first thing I thought of was maybe the weld went all the way through the cooler and created an obstruction. My friend is a precision welder and says he made sure he built the weld out and made sure it didn't go in. When the sled was running for 35 - 40 mins in garage I took a laser heat sensor and both sides of the weld were similar temperature. I am not sure if there is another way to really test it. My thought was if the head gasket change doesn't resolve my problem I will simply replace the entire heat exchanger next.

 

[nauti1]

A good machine shop could pressure test the head to see if it has any cracks while you have it off. I don't think your head gasket was bad with the comp. you have and also you would see a good bit of carbon wash on the cyl. that was leaking. from what you're saying, I would make sure that oil cooler was good or just replace it before you button it all up, cheap insurance now that you into this far.

 

[shadow44]

Hate to bring up a semi obvious thing at this point but did you make sure that all the air was bled out of the cooling system? You could have had air pockets in the system causeing overheating. If you where loosing coolant through combustion you would be able to smelll and see it coming out the exhaust in the form of steam. If you are getting that type of compression it doesnt sound like there is a leak in that area. The oily film is a little concerning though. Have you looked at the oil to see if there is any water getting into it? The cracked water jacket is an interesting one. Hey canoehead how did your friend determine he had a crack there?
I just thought of something else Did you make sure after they welded the cooler that there was not a huge restriction in the area of the weld.
Just throwing out some ideas for you. hope you find and are able to fix things up good luck.

As the Nytro has a self bleeding system this should not occur...the system bleeds as you ride.

 

[bradfr]

Engine side picture

Not sure if anything looks terribly bad based on looking at the pistons on the engine side pic. A friend of mine's father who builds old cars said the build up on those pistons do not look right.

 

[canoehead]

They do look at bit coked up!

 

[nauti1]

If the head gasket was bad, you would see carbon burn from the edge of the cylinder(fire ring) bleeding outward toward another cylinder or a water jacket. The tops of the pistons look ok as does the combustion cambers on the head. If it was burning coolant, the piston tops and combustion camber would be clean, like it was steam cleaned, not carboned up like your pictures show. The test I would have performed would be to pressurize the cooling system with a hand pump pressure tester with the spark plugs removed and look down into each cylinder with a light and see or smell if there is coolant leaking into the clyinders. Sometimes if the head gasket goes, it will pump air into the cooling system and it puke out of the resivor. If you are getting oil in your coolant, I would focus on the oil cooler, you have more oil pressure than coolant pressure.