Jumped Timing

What would cause this? Given that the motor does not get revved high and the timing belt tensioner good.

Thanks

 

[Jesh]

Do you still have your balance shafts?

 

Yes. The motor also has a loud tick in the head, even after installing 3G lifters.

 

[dustyduff]

The loud "tick" coming from the head is probably due to not properly bleeding the lifters before installing them.

 

[Wizardawd]

Skipped timing I have seen from the following:

(1) A/C belt came off and into the timing cover while running. Usually when the crank pulley is separating.
(2) BS belt broke and got into the main timing belt.
(3) Back BS bearing seizing, which in turn causes the oil pump sprocket to turn hard and occasionally skip. Eventually it locks and shreds TB. Just happened on the mighty max.
(4) Timing belt adjuster is bad. The tensioner is actually the pulley, since that is what you actually set the tension with. The hydraulic adjuster maintains tension during varying load conditions. This is the most common as most people don't know they are bad. If you can collapse it with your thumb, its bad.

Wiz

 

I replaced all the belts two months ago including the BS and timing belt. The tension of the timing belt is very good not sloppy at all. I am wondering about the balance shaft though.

However, #3 did not happen because my belt is fine and taught.

 

[belize1334]

Quoting Wizardawd:
(1) A/C belt came off and into the timing cover while running. Usually when the crank pulley is separating.



Happened to me right after I bought my car...

 

[LordAthey]

Actually my buddy his car just jumped timing one day when he was warming it up. The guy who took apart his motor said there was no reason this should have happened. I have also heard of a few cases where it jumps times, but its kind of rare.

 

[DynastyLCD]

im surprised nobody listed this, how about improper adjustment on the eccentric pulley, or possibly it coming loose? its possible that could have come free and the hydraulic tensioner picked up the slack. just a thought.

 

[Wizardawd]

Usually if the pulley comes loose it would make a lot of noise. That is a good point though because I had arguments with Kia/Hyundai about that when they removed the eccentric pulley and relied on the adjuster to maintain tension. And of course it was followed by lots of noise complaints (belt too loose) and premature belt failures because of jumped timing.

Wiz

 

[mitsuturbo]

I have seen cars with both balance shafts lose a nearly new balance shaft belt. One of which had a clean snap, right between two teeth on the belt!

While i can only speculate as to why it broke, I would guess it was from improper tension, or it was a poor quality piece to start with.

Balance shafts just cause PROBLEMS. I have always hated them.

 

[Jesh]

Like Wizardawd said... did you check your hydraulic tensioner and make sure you can't compress it by hand? I know you said you already checked it, but we just need to know for sure before we move on. I had this same problem about 6 months ago and there was a really loud ticking sound caused by the hydraulic tensioner bouncing on the tensioner arm, it actually wore half way through it. but by all appearances it seemed fine. but i could compress with one hand.