What would cause a camshaft pulley (#12 in the pic below) to come loose TWICE, even after being properly torqued to 27 lb. ft? Car is a 96 Civic Ex with a D16Y8, timing belt is new and was working fine for a year before this took place.

Driving on the freeway, engine shuts off randomly, get the car towed home, pull the VC and the upper timing belt cover and I see the pulley bolt (#20 in the pic below) like halfway out and the little nub on the inside of the pulley is snapped off.

Inspected camshaft and rockers, installed a new pulley to 33 lb.ft. just to be safe and re-tightened the timing belt, checked compression and got 180 across the board, car drives fine for ten miles and then the pulley snaps again, same exact problem!!!

WHAT'S GOING ON :taz:



HOW IT LOOKED AFTER THE SECOND TIME



THIS PIC SHOWS THE NUB THAT KEEPS SNAPPING OFF

 

i'm going to say you half stripped/cross threaded the threads inside the cam...inspect and post a pic only thing that would make sense.

 

most likely you cross threaded the inside thread. get a tap and die and re thread the hole with the same size and see if it helps.

 

The journal shown below in the middle has a small ridge sticking up and I found some tiny metal shavings in this area so I'm pretty sure this is the problem. (If you look closely you can see how it looks rounded near the exhaust valve spring.) Also the camshaft has a hairline crack that goes all the way down the threads, but I'm not sure if that was there before or if it happened when the camshaft jammed this last time. What do I do about this? New camshaft and pulley for sure, can I get the journals redone or something or do I have to replace the whole head?



Also there are these weird cracked areas next to the valve springs that don't make sense to me because the valves don't move that way haha.

 

ewww... that sucks =o/ you can have the journal's line hone and polished it if they are not scared bad. take the head to a reputable machine shop ...

 

It looks like the valve springs are flat on one side? Or is it the pic? Is your lash adjusted correctly or is it binding causing the valve springs to push out and contact the head? Damn that sucks on the head, and here I thought Honda had bearings for the cam, not the head itself!!!!

 

The lash is correct cause I readjusted it, the picture is just tweaked for some reason. And yeah it's super annoying that one small part of the head being damaged requires replacement of the WHOLE DAMN PART

 

i would just find another head. they're cheap anyway.

 

That cam pulley looks like the keyway is damaged. Also, the head scarring requires replacement. But to be frank, you could still run it like that if you got a new cam and cam gear.

 

Should I do a piston ring job and hone just because everything is taken apart or see if I get good compression numbers first?

 

depends. if it's burning oil, stuck control rings won't show up on any test.

 

Do it and the rod bearings while in that deep. It's worth it. If the head is scarred like that, it would be due to lack of oil. If you had lack of oil, I'd guess it's either burning or dripping. If it were leaking, you would see it on the driveway.