Loose timing belt

[Tobi]

Hey everybody.
330 miles on the rebuild and I have been checking on the belt everyday. Today I found it so loose that I can move it back and force on the cam pulleys with my left pinky. I turned the motor over on the starter and it did not change.
Checked on the nut and bolts of the tensioner and everything is tight. The pulleys don't seem to be loose ether.
I did not start to work on it yet because I need to go to work first.
Kind of scary that I was driving around with that last night and I am afraid that when I tighten it that it would become loose again.
Any ideas of what could have caused that are appreciated.

[BEEK]

Honestly, nothing should change, the tensioner is a set it once and tighten it down style, once tensioned the spring is not active. If the belt is loose only 2 things probably happened. 1. The belt stretched, not likely but possible, 2. The tensioner hardware was not tight and it moved. These scenarios exist only if everything else is correct, no loose cam pulleys etc

[majicwrench]

Depending on just where you check a T belt is can seem pretty loose even when properly tensioned. This is not like an alternator belt that should be tight. Can you really move it around easily on BOTH cam pulleys??
Keith

[Tobi]

Thanks guys, I looked at the bearing again and it was definitely in the loose position even though the nut and the bolt where as tight as it could be. I put the tension back on, took it for a ride and everything is fine.
I don't get it.

Ha, I know it has been discussed before but the problem only came to my attention because I don't have the belt cover on it.
With the cover on it my nice new domed pistons would have kissed my valves goodbye soon.

[majicwrench]

If properly assembled would never come loose. SO yes, if you are not going to assemble it properly, and wish to then check the timing belt constantly, leaving covers off is a good thing.
Keith

[BEEK]

make sure you tighten both bolts on the tensioner, the 17mm nut in the middle and the 13mm headed bolt as the pivot, both should be tight

[Tobi]

The M17 nut only gets 33 FT.LB.
How much torque do you put on the M8 bolt?

[BEEK]

12ft lbs, just guessing, ill check my shop manuel tomorrow.

[Tobi]

I did not use a torque wrench the second time, just checked on it and I got almost 50Ft.Lb on the nut. I am sure the first time was about the same and the nut was still tight when I found the loose belt