GUESS WHERE THE COMPRESSION WENT - VERDICT
It looks like the 2nd cylinder intake seat loosened up and broke (or visa versa) and fell into the bore and bounced around until it went into the exhaust. I note that some of it ended up in 3rd cylinder based upon the extensive peck marks over there. I think I see peck marks in the other cylinders too .
Apparently, this is a non-interference head as I assume the seat was holding the valve open when this started because I don't see any marks in on the #2 piston valve relief.
My guidance is to use a grinder to smooth the 2 and 3 piston tops out of principal. It may prevent knocking and or cracks forming. Then go ahead and bolt a used head on and see how many miles you can get out of it. NOTE - Make sure you pull the intake and shake, blow it out and inspect it as pieces may be still in the intake.
PS - Cams are cheap https://www.google.com/shopping/product/2452533445666338801?q=2az-fe+performance+camshafts&prds=eto:8223830920646767447_0;8432833620143985699_0;15686854216464714943_0&sa=X&ved=0ahUKEwiir-7fyZbtAhWFZM0KHdl8BukQ9pwGCAU but you would need new springs and retainers which means going to a shop and then they will want to grind the valves and seats which is probably more than is justified on a 200,000 mile vehicle.
#2 Piston on left
#2 on left. sunken intake on the right side.
ClassicDatsunDebate last edited by
@racinbob I’d be concerned with hot spots causing knock. Seeing as a used engine is ~$2k, it’s a tough decision.
I agree with the preignition concern in that my suggestion is to clean it up as you can without pulling the pistons. I had not as bad piston peck marks on my Type R race engine due to a broken valve guide that went through several cylinders when a spring retainer broke. I smoothed the rough parts off the head and piston have had no problems over the last 5 racing seasons.
For him this is a street motor. I'd say sand/polish the piston tops as best you can and slap a head on it and see how it lasts. Anthony is very frugal and this is a 200,000 mile car with lots of wear. I think the best strategy is to spend as little on it as he can as if the transmission or something major fails he's probably going to buy another Camry for dirt cheap and move his performance parts and cow catcher over.
dieseldub last edited by
Big time oof.
On a diesel, I wouldn't worry too much about some pock marks on the top of a piston, so long as the rings and bores were still OK.
But it's a little different with gas engines...
Not sure I've seen a valve head get hammered further up into the port. That's wild!
VincentMalamute last edited by
I appreciate the autopsy. Is it strange the intake seat fell out? My only experience with seats falling out is the exhaust valve seat on a Briggs flat head motor. It overheated due to grass clippings not being cleaned out of the cooling fins.
In the top photo, what are you using to block off the cooling passages?
That is an excellent question. It's not my car so I don't know the history. All I can think is that the head gasket has passages that the block does not. However that hardly seems likely if it came from the factory that way.... I will ask him.
@dieseldub I am from the school of cars are tougher than you think. My advice to him is slap a head on it and scrap the car if something else more expensive breaks.......
@vincentmalamute Also, I don't know if it is common for seats to fall out. It is certainly possible. As far as I know, they chill the seat and heat the head and let everything shrink/expand together....Hammer it enough times with a valve and I suppose they all loosen up after time.
Fortunately, most don't fall out in the life of the engine. Although, usually when the fall out, that defines the life of the engine.....
VincentMalamute last edited by
yah, I tried putting my seat back in with some kind of extremely high temp glue and then peening the head around the seat. Didn't work.
pip bip last edited by
@racinbob leave it as is slap some new gaskets and used head on it. see how long it goes for