Fresno.
Keep it up. Its nice to see someone else attempting this same task at the same time.
So if I am seeing and reading correctly, your chain guide/tensioner failed and your chain was riding on metal?
Interesting fail....My car has just over 100K on the clock and the pads look like new....
Now the valve spring and lifter for #5 intake...thats a different story.
Fresno.
Keep it up. Its nice to see someone else attempting this same task at the same time.
So if I am seeing and reading correctly, your chain guide/tensioner failed and your chain was riding on metal?
Interesting fail....My car has just over 100K on the clock and the pads look like new....
Now the valve spring and lifter for #5 intake...thats a different story.
Hey, I`ll upload new pics soon. Fresno is not so far away from here, we should meet up once both cars run again
As for the engine, indeed, the primary reason for the engine failure was the excessive wear and subsequent detachment of the chain guard. I think the chain picked up a piece of the guard on the opposite side and somehow made the timing to jump. Otherwise I can`t explain why the timing was messed up and the valves touched the pistons. Failing of these guards is frequent in these engines, yours may have been replaced earlier, or the 3-chain engines have a different design? BTW, my car has 100K miles in it and I don`t think it has been taken apart.
I was gonna stop with the teardown at this point, since i found the culprit for the engine failure and I thought after rebuilding the heads and the timing everything can go back on and the engine is ready to go. Yet, I thought it would be a mistake to reassemble the motor without knowing what the piston rings and rod bearings look like, especially because the valves were touching the pistons. So I decided to go more deeply into the engine if I got this far. First, I removed the IMS cover:
This is still the original dual-row bearing, the original grease has long been replaced to engine oil that`s flowing out from the IMS cavity. The bearing looks in great condition though.
Splitting the cases after removing a bucket of nuts and bolts:
Apart:
I think it was a good idea to remove the pistons: the rings are stuck into their grooves with gunk. Oil change wasn`t a too frequent practice here. I don`t think those rings were sealing too well..
This chain guide is badly worn too. Seems a bit undersized for this job. Note that the four other rails for the timing chains were in perfect condition.
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