2G - Timing Belt: Slight Wobble/Noise

So I was planning to go to TMP this Saturday for opening day (rain or shine).

I got the alternator issues resolved routine fluid maintenance and I went for a quick drive around the block and let it idle for a good amount of time without any hiccups.

I start the car the very next day and this. The video might only highlight the noise, but there is a visible wobble going on.


A little bit of background:

When I was replacing the alternator last week I noticed the timing belt had been setting roughly 1/4" off the gears (towards the outside - engine mount). Going back in my memory, it has moved slightly more since Magnus re-surfaced the block last summer & new head gasket (long story short - head lifted @ 26PSI)

and it was slightly loose - typical since it's been only fired up few times over the course of 9 months. I thought no big deal, once the engine gets spinning it will re tension and all is well.

I'm planning to drop the TB tomorrow/Saturday but I just want some thoughts on what it could be so I can expedite the part order by then.

I'm thinking harmonic pulley/tensioner...?

Bashar, its the tensioner pulley arm. It wears out on its pivot and causes the belt not to be centered, or will cause it to move back and forth on the cam gears.

Two things keep the belt in line. Oil pump sprocket and tensioner pulley.

If the arm that the tensioner pulley is bolted to gets some horizontal play at its pivot, will lead to the timing belt not being centered.

A loose crankshaft sprocket bolt will cause this as well.

I thought Ziggy carried the Tensioner pulley bracket, but I can only find it for N/T on the website...looping.

Typically the bolt holding it wears out or the actual arm?

I'll see if I can grab the special tools to make my life easier and double check the crankshaft sprocket.

I think two things happen to the arm itself:
- the pivot hole goes out of round (it's that big hole at the very left in your picture)
- the surface that the hydraulic tensioner piston touches gets dented/warped

The above two points are correct. I've found that the bushing in the pivot hole wears out over time. I've fixed a few DSM's with the same symptom already. When the tensioner arm is bolted up it should only move vertically. When you take the timing belt off, wiggle the arm side to side. Any play here will cause the arm and tensioner pulley to angle outwards towards the timing belt cover when the engine is running.

Since the engine rotates clockwise the belt spins around the tensioner pulley before getting to the cam gears. Any belt alignment issue at the cam gears should point towards the tensioner pulley not being in line.

The hydraulic tensioner also wears the little dimple in the tensioner arm, which will throw your measuring process off when tensioning the belt. A little wear is ok, but if it starts getting in deep I would replace it.

We rebuild our engines, change all timing belt components, but still reuse that tensioner arm over and over again. They are starting to wear down with all the km's they've been put through, so its a good thing to replace anyways.

Of course, don't just order the tensioner arm. Best is to take off your timing belt and confirm what exactly is wrong. Could possibly be something else too.

The crank pulley had a couple of nice "chips" in it at the very outer ring. I don't feel comfortable re-using this piece.

From what I read, it's best to stay OEM when replacing pulleys & belts. But if I have to replace it at lest 1 more time, that would pay for an aftermarket pulley.

any thoughts?

The proper aftermarket pulley is very expensive from what I remember...there are cheap ones but they do not have the rubber insert and are not recommended. I would stick with OEM for that item for sure!

^^^
"Fluidampr" is the proper one.

couple of pictures:








maybe I`ll give the Fluidampr a try.

any tricks to get the alternator & water-pump pulleys out...I cant get it to clear the side of the engine bay (under the mount) i tried lowering & raising the engine few inches but no luck.

Put a jack with a block on it under the basepan, then remove the upper driver's side engine mount, and lower the motor down until you have enough room to take the crank pulley out from the bottom

edit: maybe I screwed that up, why are you taking those other pulleys off?

that's what I'm doing (under the oil pan)

they are in the way of the timing cover. How much room do you have moving the engine up&down before putting to much stress at the other mounts trans&axles?

Hmmm, it's been awhile since I've done this, but you shouldn't need to disconnect any other mounts to get the timing cover off.

It should give you about 3-4 inches of room before you are putting a lot of stress on the rear transmission mount.

Anyone else care to chime in, I haven't had to do this in about 3 years!

I did a timing job on my old 95 tsi awd a couple of winters back, and all I had removed was the driver side mount.. the water pump pulley was a bit of a b!tch to get out, but it wiggled free. Had the motor sitting on a jack on a piece of wood, slightly lowered also.

Stick the jack under the front steel part of the transfer case instead of supporting the engine on the pan. Once the mount is removed the engine will tilt over. You don't need to touch the other mounts, nor will you stress them with the jack removed.

Thanks Reza, that did the trick.

so it turns out one of the engine mount bolts that holds it to the block was missing. The bolt towards the firewall & idle pulley.

does anyone have dimensions for this bolt

talk about lucky...the timing cover kept everything in line just enough or it could of been a disaster

Can someone give me an inside look at what is happening here

Number "1" is what I'm missing, and it seems that not only is the bolt & washer are gone, but also the stud that holds them.

I went down to the Mitsu dealership and I believe the:

stud's part number is MD174184 (Can someone confirm)
Nut & washer are MD129421& MF241251

is this stud part of the block?

(1) should be a stud in the block
The other two are bolts.

I've never seen a loose stud like that, but I guess it could happen, or maybe it was never there to begin with (when the motor was built) and the other two bolts worked themselves loose.

It either wasnt there to begin with or most likely snapped offs which would explain the noise.
I'm thinking everything comes off and I'll re-drill for a new one

Same thing happened to me.. except they all came loose.
I must have had that timing side pulled 8 times looking for an oil leak, and a whoooing noise, and never noticed the loose bolts... I must have been blind.

I nearly avoided disaster aswell. and I lock-tighted the SH!t out of those fasteners.