Top of timing belt marks?

[98mitsubishigst]

I have two pictures attached..

I started getting a weird belt like tapping noise one day, and you can only hear it from drivers side, and wear the belts are.. its not a rod knocking or anything, but i can't seem to come up with the answers of what it is..

But anyway's its really bothering me. So i pulled the upper timing belt cover, and saw these weird markings on timing belt..

Are these normal?? No frays on edges or anything..

 

[rlacasse1]

Are you talking about the dark lines across the belt? If so, yes, but I've not seen them that distint before. They're usually a little lighter.

Or are you talking about how it looks like really light scratches running the length of the belt? If so, no. That's not usual. But my eyes may be playing tricks on me, I may be seeing something that's not there.

 

[bryanwheat]

How old is that belt?

 

[chaclark83]

The timing belt tensioner works kind of like a spring loaded strut. If the seal blows inside it it will let the arm on the tensioner pully slap the tensioner. I would check it first.

 

[RayBan GST]

can you take one more picture from the side ? showing the marking ? also how old is that belt ?

 

[98mitsubishigst]

Less than 30k miles.

The dark marks look really distinct to me for some reason, and same with the white lines up the belt.. it seems odd to me..

 

[bryanwheat]

The belt looks kind of old to me. I would replace it if mine looked like that.

 

[rlacasse1]

That is odd. I've seen higher mileaged belts that weren't that bad. I would do some checking if I were you. If it was my car I would be a little suspicious.

Did you do the last timing job?

 

[JusMX141]

It's just some marking from the backside of the cogs. Everywhere there's a cog on the belt, there's a dark mark. The Gates belt from my FWD looked identical to this when I tore the engine down a long time ago. As long as the cogs themselves are still soft and not trying to rip off the belt, it's probably fine.

If you suspect the tensioner of being bad, you may want to pull the lower cover and have a look. I've seen tensioners break before right at the hole for the grenade pin, causing a sound very similar to what you're describing.

If one of your pulleys locked up for whatever reason, the entire backside of the belt would look "polished", like this:

 

[DSM1G90]

Dang, that tensioner pulley definitely took a dump down south. What cause that one to fail .. age?

True, I usually don't pay attention to the top of the belt as I do with the teeth themselves: if they stay pliable where you can pinch the teeth between the fingernails and still push in rubber, and at the base of the tooth on each side isn't showing wear and torn, it's just normal wear on the belt.

Once the teeth get's harden up and showing fabric tear at the base of the tooth is when you'd better pull it pronto.

 

[JusMX141]

Dang, that tensioner pulley definitely took a dump down south. What cause that one to fail .. age?

Probably. The belt and pulleys were on Christi's non-turbo, and I'm 99% sure those were all parts we recycled from my buddy Jeff's '95 TSi back when he owned the car that she now drives. He just wanted to get the thing running as cheap as possible, and he had the old OEM stuff laying around so it went on. My best guess dates that stuff to around 170,000 miles unless it was changed prior to Jeff owning his 2G.

The funny part is, and I'm sure you can't tell from that photo, but the belt itself is about half missing width-wise....and it was also half walked-off the cam gears when I removed the cover. The width of the belt that was actually driving the cam gears was less than the width of a balance shaft belt...and we figure she drove a few hundred miles with it like that from the time she first told me it was making an unusual noise that I wrote off as a bad water pump.

 

[rlacasse1]

Wow, and that thing didn't get out of time? That's amazing.

 

[xxNocturnalxx]

The belt almost looks too thin, like being worn down by a siezing or lose pulley.

 

[1983gsp]

The timing belt tensioner works kind of like a spring loaded strut. If the seal blows inside it it will let the arm on the tensioner pully slap the tensioner. I would check it first.

^--- this

 

[1Badvan]

I agree with you, looks like the belt walked and sheared off over time. I just got done doing a factory timing belt change and there is 1/8" or less on each side of the belt where the cog shows.

 

[JwpRider]

Originally Posted by JusMX141

"The funny part is, and I'm sure you can't tell from that photo, but the belt itself is about half missing width-wise...."

Damn, than is the picture of the month! Did you ever 'find' the rest of the belt? Was it 'shaved off' over time, or just split in half and disappeared. Did you see any evidence of shavings or spots where it rubbed? At first look, it seems like it is just the wrong belt...

 

[98mitsubishigst]

hahah i hate to ruin this topic over justin's timing belt that isn't on the car anymore, so there is no problem with his car at the moment, but id kinda like more response to what you think is on my timing belt and if its normal? hahah

 

[JwpRider]

Sorry to get off topic..
I would get a poor mans stethoscope (piece of garden hose or slighty smaller) and see if you can locate the 'ticking sound'. Would be best without the timing belt cover, but we all know that is a pain to get off/on. Maybe you can locate the noise. If the noise stops with the cover off, then you are onto something!

If the belt is dry (no oil etc), plyable, not frayed and appears OK, I would just keep an eye on it to see if the appearence changes over a week or so. If it does, may give you a hint...

I would bet that most members don't have a belt with 30K miles on it...so trying to compare may prove inconclusive. This may be what a 30K belt looks like.

 

[xxNocturnalxx]

That is not what a belt looks like at 30k unless it is some seriously cheap crap or has a 100k+ on it. It is being wore down prematurely.

 

[MHuddy1213]

my belt has 35k on it and it looks nothing like that my looks in really good shape in comparrison something is probably prematurely wearing it away like nocturnal said but thats just being compared to my belt and i have the oem belt on

 

[miguelmcv]

My timing belt was exactly like the (OP) looks like, and I never new what was it, It had 1 thousand miles on it and it was always leaning to the front of the gears, It never stays on the middle of the gears, It had all new timing components (Tensioner, Idle pulley etc), But it never had a noise coming from it.
I never figure it out, which I took the engine out for a rebuild.

I will go with what justin stated.

 

[xxNocturnalxx]

^ The issue here is not where the timing belt rides, It's how thin the belt is.

 

[rlacasse1]

Well my suggestion would be to pull the timing belt cover off and start the car. Then sit there and watch the belt for a minute to see if you can figure out what is causing the issue. that would probably be your easiest way of figure out exactly what is wrong with it.

^ The issue here is not where the timing belt rides, It's how thin the belt is.

If you are referencing the belt pictures that Justin (JusMX141) posted, then you are looking at the wrong pics. That is not the belt in question.

It's the one in the very first post that the OP is having an issue with. There is no thinness issue with it. (btw, that's what she said)

 

[miguelmcv]

^ The issue here is not where the timing belt rides, It's how thin the belt is.

NO, Is not how thin the belt is, is about the look of the timing belt (TOP),
You might be talking about Justin's Post, which is not the problem of the OP.

The OP is asking about the sound and about the timing marks on top of the belt.

That was what I was referring to.

 

[rlacasse1]

Ok, just making sure. Cause you mentioned how thin the belt was, so I figured maybe you were looking at the later pics as well. All is well.