what would cause the timing belt to jump?

[bnpimpn]

if i had an decently new timing belt on my car....what would cause it to jump? would driving it exesively hard be a reason? just starting it up on a cold morning cause it to jump?

(my timing belt never broke, it just jumped enough to bend valves, while under my mechanics supervision)

 

[Pure92TSi]

Auto tensioner could have given out. If it did it would allow the belt to become loose enough to jump timing. Or if it was not set properly in the first place it could have done this. I know there are more reasons but for some reason I can't think of them right now, I'm a little tired sorry.

 

[bnpimpn]

so u dont think that if someone were to drive the car really hard, that it would cause it to jump?....if the tensioner wasnt set propperly wouldnt it do it right after they replaced the belt....not a year and a half or so?

 

[bnpimpn]

so u don't think that if someone were to drive the car really hard, that it would cause it to jump?....if the tensioner wasn't set properly wouldn't it do it right after they replaced the belt....not a year and a half or so? or could the jump be a combination of an incorrect tension&extremely hard driving?

 

[Old Mitsu Tech]

If the belt jumped and did not break, after it was freshly installed I would almost guarantee a step was omitted from installation. Like was said above, either the auto tensioner was not replaced, or it was not set properly. Almost all of these posts I see that turn out this way can be attributed to these two things.

When you are done repairing and are installing the belt, post and we will go over your questions so this perhaps won't happen again.

Good Luck

 

[mobythevan]

if the tensioner wasnt set propperly wouldnt it do it right after they replaced the belt....not a year and a half or so

mine jumped after 10k miles because previous owner didn't replace the auto tensioner and it went bad and let the belt go loose. You can push the rod on the bad auto tensioner in by hand now.