Noise from timing belt area.. tensioner loose??? Help needed

painemann · **Joined:** Sat Dec 20, 2008 7:02 pm **Posts:** 607

Well i took off the timing belt cover with intention of finding the howling noise from the area and it seems as if the tensioner in a little loose. Obviously the belt will stretch over time but is it normal to loose this much tension? I don't have the pin tool but I'm sure I can come up with something to get it back to tension. What would you recommend, just re set the tensioner and hope for the best or replace it. I want to say the whole timing belt and accessories has around 45,000 on it.

I would like to get it back together this weekend so any advice would be awesome!

Oh and Have a good 4th!!!! :rockon:

Hexus · **Posted:** Thu Jul 04, 2013 6:21 pm

That's not very much tension loss at all, I would expect at least that much when putting on a new tensioner and turning the belt a few times to ensure timing was right.

Tensioner looks good for the mileage on it.

That's not to say the bearings are still good in it, that's another inspection, but tension is not your issue here.

thermorex · **Posted:** Thu Jul 04, 2013 9:43 pm

Isn't the tensioner supposed to stretch to the right (and not left like it is)? I'm thinking when the belt gets loose (or more exactly rubber wears a little) tensioner will try to compensate and move to the right to tie the belt. I may be wrong, but this is what I remember.

Anyways, I dont think is a problem either way.

Happy 4th to you too guys!

CRDsyeruncle · **Joined:** Fri May 10, 2013 10:03 pm **Posts:** 71

When You first put on the belt, even though you tension it, when you turn it over, it "seats". You gotta re-tension it proper. That is definitely loose/soft.

factory53 · **Posted:** Fri Jul 05, 2013 1:01 am

My Jeep just started making a loud squeaking noise too from one of the pulley's at the front of the engine. Not sure which one it is but it's loud and very annoying.

With regards to the timing belt. Is this a hard thing to replace? Just wondering if I should just get a mechanic to do it for me or is this something I can do on my own?

Cheers,

papaindigo · **Posted:** Fri Jul 05, 2013 9:37 am

thermorex - you have it sort of backwards, easy to do and I've done it, since this is a mechanical not spring loaded tensioner. The serp belt tensioner is spring loaded hence as the serp belt stretches the tensioner pivots in the direction forced by the spring to keep steady tension on the belt. This a critical design feature as the serp belt drives several "clutched" things and must flex some all the time to keep a steady tension on the belt which is why the serp belt tensioner bounces when the alternator clutch pulley goes bad and upsets the amount of belt flex. The TB does not drive clutched things and just runs. In that case the tensioner functions based on an internal eccentric with an external marking spring but no internal spring to add tension as the belt stretches. As the TB stretches the tensioner more or less relaxes (probably not the proper term) vs the marking spring which is why it appears to shift left. This is exactly the direction that it shifts when you rotate the engine to seat a new TB and have to readjust the tensioner. In theory and largely in practice the Kevlar TB reinforcement keeps the belt from stretching too much.

In this case the tensioner is barely off the mark and not really in need of adjustment unless loosened to replace whatever bearing is bad.

painemann - assuming the cooling system is hooked up I'd crank it up and see if you can figure out what bearing is howling. Once identified replace it and retension. See the GDE forum timing belt document for how to use a couple of allen keys to adjust the tensioner.

factory53 - your noise is likely a bad alternator clutch, at idle look down serp belt to the tensioner, if it's bouncing a lot (not just twitching) you need to replace that clutch or see if you can get a rebuilt alternator (I'm not familiar with options in Canada) or it could be bad idler pulley bearings. NOTE several have reported noised from like the AC clutch that were actually caused by a bad alternator bearing. The TB replacement with proper tools or proper substitutes is something someone with decent mechanical skills can do. Check Sam's NOOB guide for how to and videos (FYI removal of all that front end stuff is wonderful for access but not absolutely required to do the job)

thermorex · **Posted:** Sat Jul 06, 2013 1:09 am

Papa, what you said is entirely true, I'm not saying anything against, what I meant is that once tb seats and tb tensioner is re-aligned, as tb wears (after tens of thousands miles), the tensioner mark moves to the right not left since by wear, tb becomes "larger in diameter" or thinner, and the tb tensioner spring tends to cut the slack resulting from wear. In other words, my logic (and again I may be wrong) tells me that after many miles and some wear on the tb, tensioner mark should be moving towards right, from the initial mark from when it was left when timing belt had been replaced.

geordi · **Posted:** Sat Jul 06, 2013 3:25 am

You'd think that would be the case, but it isn't. The spring is pre-loaded when you tension it, and as the center with the arm is allowed to adjust as the belt thins out, it gradually draws itself toward the left, to appear as you show in your picture. The arm is not fixed to the center shaft IIRC, there is another relationship happening in there.

Logic doesn't really have a place in the design of this motor anyway. Your tensioner could use a bit more pre-load if this was a new belt. As it is an old belt, that image is totally fine and what I'd expect to see if I was opening up the timing cover for a job.

DOC4444 · **Posted:** Sat Jul 06, 2013 5:44 am

Once he finds and corrects the offending bearing, is there any reason, with a half worn belt, NOT to reset the pointer so it lines up with the slot?

DOC

Glend · **Posted:** Sat Jul 06, 2013 8:14 am

It could be one of the timing belt idler pulley bearings, they are suppose to be changed with the belt (according to VM HK).

Hexus · **Posted:** Sat Jul 06, 2013 8:39 am

I think I said all that stuff in the first response about the picture.

I begin to see why others have stopped responding in posts and have switched primarily to PM only responses.

...and that's about as nice as I can keep my commentary.

geordi · **Posted:** Sat Jul 06, 2013 12:09 pm

DOC4444 wrote:

Once he finds and corrects the offending bearing, is there any reason, with a half worn belt, NOT to reset the pointer so it lines up with the slot?

DOC

I do not agree with this idea. You are talking about re-tensioning a belt that has already had a significant amount of miles and potential stretch worn in to it. Whether the kevlar stretches or not (I do not believe kevlar stretches much, if at all) but now the belt has less material on it to protect the kevlar from the tensions from that tensioner. I would snug it up if anything, not pull it to full fresh tension... But with the belt from Amazon being only $75, and a full top end job being $500 or more.... Why are we even talking about this?

DOC4444 · **Posted:** Sat Jul 06, 2013 2:29 pm

Since he has it this far apart, are you suggesting the smart thing to do is to put a new belt in along with replacing whatever is making the noise?

DOC

geordi · **Posted:** Sat Jul 06, 2013 3:21 pm

Yes. This is not a question or an area to trip over dollars to save a few pennies.

Better safe in the knowledge that the belt is new and not stressed, and who cares when it was 'supposed' to be due? That is also why I don't subscribe to the 'change the water pump with the timing belt' schedule, because it is bullshipt. The water pump in my CRD lasted 133k miles, and was not bad when the engine failed. The water pump in my TDI was replaced by a dealer (previous / original owner) at 100k miles and at 200k miles... And it was weeping from at least 245k miles, probably earlier than that, when I bought it at 244k. So that pump lasted less than 50% of its lifespan, maybe the prior pump would have gone the distance twice?

Either way, at 268k miles, There I was hanging my motor by a shop crane to dig out a water pump that should have had another 40k miles to go. I changed all the rollers and the tensioner and the belt at the same time, because they were cheaper than risking re-stressing an already worn-in belt (and the rest came in the kit from idparts).

When I was tearing down my CRD motor trying to find the head problem I thought it had, did I replace the belt? No, not at that point, because I was still diagnosing the real problem. IF I had gotten it fixed, I would have left the used belt in there only for as long as it took a new one to arrive by UPS.

I spent $1000 on parts chasing a problem that was in the bottom end - Does $75 for a belt really matter in that case?

painemann · **Joined:** Sat Dec 20, 2008 7:02 pm **Posts:** 607

Well as already said I wish I had all the parts and tools while I was all the way down to the belt! I would have just replaced everything and started fresh.
I thought I found a slightly noisy idler pulley but I can still slightly hear the sound after re-assembly. I am going to let it be for a while as I took the tensioner off and it seemed fine. I am going to plan on doing the belt job again soon anyway.

Noise from timing belt area.. tensioner loose??? Help needed

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