Timing Belt Tension?

[philjw90SHO]

I have a 1992 MTX with about 108k miles. I did a full 60k about a month ago and everything was running great until today. It still runs and idles fine but there is a new noise. I think it might be coming from the timing belt because the water pump is new.

I did slightly bump a curb right before it started making the noise but what could that do to make a noise on the other side of the car.

My question is, would manually tightening the spring be a bad thing. The spring wasn't putting enough tension on the belt so I pushed the tensioner against the belt and tightened the bolt.
The belt is new. Thanks ahead for any responses.

 

[RI-SHO]

Is it like a grinding/groaning noise at certain RPM?

If you can I wouldnt suggest driving it at all till you can retension the belt again, you dont want that belt coming loose at all. If you can reach from up top try to push/pull on the belt itself and see if there is any slack at all.

With a new belt there should be a very small amount of movement because it isnt fully broken in, into about 10,000miles.

 

[projectSHO89]

You cannot touch the timing belt without removing the timing belt cover. There as should be the least amount of play in a new belt. It will stretch as it wears.

However, you can adjust the tension on the timing belt through the small, square access port in the timing belt cover.

Pop the cover out, loosen the bolt that secures the tensioner, allow the tennsioner to push against the belt by its spring tenstion, then retighten the bolt and reinstall the cover.

If the noise can be produced while the car is not moving, get a mechanic's stehoscope and carefully do your detective work. Psychic troubleshooting is about as reliable as Miss Cleo was.

Steve

 

[sdpatt]

The crankshaft must be positioned at the 60 degrees before top dead center (BTDC) position before the timing belt tension can be correctly set. That is the only purpose of the first, yellow mark on the crankshaft damper.

To reset the tension, rotate the crankshaft in the normal clockwise direction with a wrench on the crank bolt, or your hands on the damper, until the yellow mark on the damper is aligned with the "0" mark on the lower timing belt cover. You can then pop the little rectangular door off of the lower belt cover (flat tip screwdriver under the aft (rearward) end of the door), loosen the 14mm nut on the tensioner a half turn and then retorque the nut to 27-35 lb-ft (IIRC).

This is the correct method to set the initial tension of the timing belt on the 3.0L SHO engine and can be redone every 10,000 miles or so to maintain the correct tension on the belt much like the 3.2L's gas piston tensioner. What this procedure doesn't compensate for is the loss of camshaft timing accuracy due to the streching of the belt. That is why replacing the $34.77 belt every 60,000 miles is still a good idea to maintain the SHO's performance at its best.

Search keys: timing belt tension 60 degrees BTDC

<small>[ February 06, 2003, 02:35 PM: Message edited by: sdpatt ]</small>