My 2000 5vz-fe chewed the timing belt. Went to line up the timing marks so I could put a new belt on and now the passenger cam only rotates halfway then stops. Engine has maybe 5k after rebuild last winter. Seems like valves in cylinder 1 aren't moving when I rotate the cams with valve cover pulled. Lobes won't move the valves. Any insight or ideas would be greatly appreciated before I spend 650 on a rebuilt head.

 

This should be a non interference engine, buuuuut if the valves floated a bit or something else crazy happened you could have a bent valve. Was it running when you took it apart? If so, likely the valves are fine.

It’s also possible you trapped compression in that cylinder. Try taking the spark plugs out and see if that allows the cams to turn better.

will the cam turn the wrong direction? To turn the cams you have to push against all the valve springs. There is a sweet spot that the cam will turn to where most of the springs are relieved and it’s tough to turn the cam. If you can back the cam up anti rotation and then rotate it forward normally do you hear any metal on metal clank when it stops?

 

I assume you replaced the t-belt when you did a rebuild last year, it should last longer than 5K!, T-belt brand, and what did you rebuild last year.

 

Sounds like the non-rotating cam shredded the belt.

I think that head is going to have to come off. Either the valves are stuck tight in the guides for some reason, or there's something bad happening inside the cylinder.

 

I'll try pulling the spark plug and see if that does the trick. pulled it a few weeks ago when timing jumped on me due to failed hydraulic timing tensioner. put new tensioner on reused belt as it still looked brand new. MISTAKE!!!!! ran fine a few times then went to change wires and coils as it was developing an intermittent miss fire. changed those and would fire. just rotated like it did when it jumped time two weeks prior. i pulled the timing cover to find the belt chewed removed it and went to rotate the cams to put the new belt on and the passenger side cam would only rotate back and forth a half rotation.

 

Yes new t belt but i neglected to change the tensioner. All new bottom end. used heads and overhead cams. the valves and lobes on the cams looked great and within spec.

 

Any update? Did pulling the plugs get the cam to rotate? Did you pull the head?

 

I've been meaning to get to it.. Will be pulling the head tomorrow if pulling the spark plug doesn't work. I will update tomorrow evening.

 

The valve buckets ended up being stuck and gunked. I used engine assembly lube when putting the top end together the first time. This time after pulling it all apart and cleaning I used motor oil. 1500 miles and running strong. Just sold it and bought a 98 4runner with the 5speed instead of auto. FINALLY.