So my friend and I did the TB on his 2003 EVO about 20k miles ago and every thing has been ok until yesterday. He called me to tell me that he was having idling issues and could not track down the problem. He and I talked about the usual stuff that it could be and he checked everything with no success on fixing the problem. Later that day he got a CEL and pulled the code which was for "Cam position sensor". I said we better check the timing. Put the crank at TDC and sure enough the exhaust cam gear was off by two teeth and the belt had too much slack in it, we had found the problem. So we start to take the lower cover off and them remove the belt tension pulley and hydraulic tensioner. After inspecting the hyraulic tensioner it was ok and to the eye the tensioner pulley was ok but upon further inspection when spinning the pulley it had a slight vibration in its rotation and if shaken sounded like it had worn bearings. This is the original tensioner pulley with a car that has about 80k miles on it. So I guess the vibration from the bad bearings turning in the pulley caused the essentric part of the pulley to turn on the bolt and let out tension on the belt. I guess that sounds right because it is the only thing I think that could of gone wrong to cause the belt to jump and skip two teeth on the exhaust cam gear. Anyone else care to chime in on anything else we should look for?

So far I am going to chalk this up to a lesson learned that at 60k miles TB belt change go ahead and replace the tensioner and pulleys. Luckly my friend got lucky and no damage was done.

 

that sounds right. vibrations slowly loosened the tensioner pulley. I think that thing only get tightened to like 31in/lbs (for belt tension not the bolt) off the top of my head. It was a small number and difficult to do with a regular torque wrench as there wasnt enough room to fit the socket onto the bolt to tighten into position.

I would definately (and I did) replace all pulleys and tensioner.

 

make sure you know how to properly set the offset pulley and tensioner.

 

Yea I went back and read through alot of threads about people questioning to replace them or not. Wanted to make this new thread to get peoples input and also be a warning that you should for sure replace them.

 

I'm fairly certain that you can get the "timing belt kit" from several vendors on here which includes the pulley as well as the timing belt and balance shaft belt. The FSM recommends replacing it at 60k with both belts. Of course if you have removed your balance shafts you will have more vibration and may need to change it more frequently. (mine is coming up shortly! LOL) Check with Chris@nolimitmotors for a good deal on the setup, I have gotten a large quantity of my parts from him and always had super fast shipping and great service.

Glad to hear no damage was done!

Josh

 

My buddy picked up the new tensioner pulley this morning and we confirmed that the old one was bad. Installed the new one and all is good. Word to the wise, change those tensioner at 60k!!!!

 

That is timely information. I just noticed an increase in the volume of the whine that normally comes from that area, and suspected an issue with the tensioner and/or pulley. A change in the volume/type of noise often indicates a looming issue. Seeing this adds to my suspicions.

My head, pistons, and valvetrain are worth far more than tensioner and pulley, so the car is grounded until we change them.

 

good to know ! if that code ever comes up

 

I wouldn't recommend waiting for a code. When that happens, things are already seriously amiss. I'd change them whenever changing the belt.

 

You used to be able to buy the Mitsubishi tool for setting the tensioner pulley timing off of ebay. Thats where I got mine years ago. It has two prongs to fit into the tensioner pulley and is made for 1/4" drive ratchet so you can measure the torque to set the belt tension.

 

Yea that would be a tell tale sign. His tensioner pulley did not roll right, had a vibration to it when spinning and when shook it you could hear the bearings rattling inside of it. His new tensioner pulley was solid, smooth and made no noises when shook. I imagine with how it spun in my hand that when on the car it had to of made some noises that could of been a warning.

 

This is my first posting, so sorry in advance if i post this in the wrong location....but do any of you detailed procedures for replacing timing belt and tensioner pully?...thanks

 

so for this change i would need a timing belt, water pump the tensioner and how many pullies?

 

I hope tensioner is no the only thing you and your buddy replaced. At this point, I would say do the whole timing belt or at least remove it and re-install it since timing belt is skipped by two tooth. My thought

 

There are two timing belts and three pulleys.