Finally got around to finishing pulling the head on my 1990 trooper. Thanks to all those who helped me out, I couldn't have done it without the forum!
A little background first: I pulled the head because I knew I had head/head gaskets problems. First indication was stumbling at idle, accompanied by white smoke out the exhaust. No overheating involved, these symtoms first appeared after a cold start! Not realizing what the problem was at first, I shut the engine down for a few hours before trying to restart. When I tried to restart the engine would not turn over at all...it had hydrolocked!! At this point everything came together and I realized what was going on. I was worried I had really screwed up the engine at this point, but I pulled the plugs out and cranked the engine over to blow out the coolant. After putting the plugs in it started right up and idled fine, with no apparent problems. I revved up to 2500 for a few seconds and everything seemed fine, no vibrations or strange noises. So hopefully the hrdrolock didn't damage anything?<img src="/forums/images/graemlins/confused.gif" alt="" /> By the way, the engine has 156,000 on it and has never had the head off. So after pulling the head, here are some pics of what I saw:
PIC 1 PIC 2 PIC 3 PIC 4 PIC 5 The head gasket is in place in the first pic, and the broken part you see sticking up over the piston is part of the gasket. It should be more clear in the next pic. The remaing 3 pics are all of piston #4 itself. So, the head gasket obviously failed, but exactly why I don't know. By the way, all these pics are of cylinder #4, since that is where all the problems are...the other cylinders look fine.
What I am really concerned with are the 2 little chunks that the head gasket apparently bit out of the piston somehow. Hopefully they are fairly clear on the images. They are right underneath where the head gasket failed, and based on their shape look as if they were caused by the broken head gasket impacting the piston crown? Looking at the cylinder wall in #4 piston there is no apprent scoring, no sign that loose metal caused any damage to the wall. Rotating the engine over by hand everything turns smoothly, no strange noises. I looked at the head itself and couln't see any cracks, but intend to magniflux it to make sure. The undersides of the valves look fine.
So my question is what is the implication of the piston damage? Is it severe enough that I need to replace the piston? <img src="/forums/images/graemlins/confused.gif" alt="" /> Or is it mild enough that I can just throw on a new head gasket and continue to drive without worry? What should I do? I know no one can say for sure, just looking for some advice since I have no clue. As always, thanks for any help!! <img src="/forums/images/graemlins/cheers.gif" alt="" />
EDIT by Mod: If you would like to resize those pictures, you can put them back into this thread. But they are just a bit big as they are.
