Noise after TB job.

themightyquinn

Well-known member
Joined
Mar 7, 2005
TDI
1999 New Beetle Black
My mom had some surgery the other day that makes her unable to operate the clutch pedal, so I decided to use the time to give her a b'day/xmas present of a t-belt job. She has no idea when it was last done, the last time I know it was done was ~80K miles at the dealer--the car now has 212K. She thinks she had it done when she was in Texas (~130-160k), but no receipt.

So, I ripped it apart, ended up being a PITA. Someone had already stripped out some of the VC bolts, and 2 of the balancer bolts. Looked like the original WP, and with the camshaft locked down the TDC mark on the flywheel wasn't even visible. Belt looked OK, but there was a little cracking when I flexed it, and it was a D.

I corrected the timing mismatch (2x close but no cigar first go round:(), replaced the 3 rollers, bolts, etc. All in all typical deluxe TB job.

Fired it up, and it started well (she's been complaining of hard starting--well no wonder :rolleyes: with the valve timing so far off). There's a noise coming from the TB area now. I'm pretty sure it's new, or at least much louder.

It's kind of a whirring, but there's a clicking to it as well. It does kind of sound like the cards in bicycle spokes. I can't really isolate the location. Sometimes I'm convinced it's the tensioner (it's normal for it to be constantly adjusting as the car runs, right?), sometimes I think it's the upper roller, and sometimes I think it's the IP. The new belt does seem to be tracking closer to the block than the last one did (1/8" of clean pulley is exposed up top).

Has anyone had a bad idler or tensioner out of the box? Could I have damaged the IP somehow that it's making the sound now? Are there MP3s of bad IPs? Any suggestions? I tried a makeshift stethoscope, but didn't come any closer to figuring it out. The tensioner can't be replaced without removing the mount, right? The tensioner can be replaced without going beyond that, right? The upper roller can be replaced without removing the belt as well, right? I guess at this point I'm going to order a new tensioner and idler, replace them and go from there.

Thanks.
 

hevster1

Vendor
Joined
Nov 14, 2005
Location
Columbia NJ
TDI
98 NB
I am assuming this is an ALH? The tensioner on an ALH does NOT self adjust. You set the tension then it should remain the same. I have never had a bad tensioner/idler out of the box BUT that doesn't mean it cannot happen. Recheck your work to make sure. If you catch the mistake now it is an inconvenience. If you wait and it lets go it is big bucks.
 

gforce1108

Top Post Dawg
Joined
Aug 2, 2006
Location
Newburgh, NY
TDI
04 Jetta GLS BEW, 14 Audi A7 V6 TDI
Someone else had posted a similar sound when they had the belt around the wrong side of one of the rollers. The toothed side was rolling instead of the smooth side.
 

paramedick

TDIClub Enthusiast, Vendor
Joined
Jul 29, 2001
Location
Versailles, Kentucky
TDI
2015 Audi Q5 TDI
Sure sounds like the timing belt is on the wrong side of the small lower roller. It will make the sound you describe as the teeth of the belt goes over the roller.

Good news, fairly easy to fix. Line everythng back up and lock. Release tension fully on tensioner. Pop the cam sprocket. Pull the harmonic balancer and the lower TB covers. You can get to it to remove the bolt and put the TB on the correct side. If the belt is undamaged, follow the timing belt .pdf to put everything back together correctly.
 

themightyquinn

Well-known member
Joined
Mar 7, 2005
TDI
1999 New Beetle Black
#$%@. I've never made a mistake like that before, but that's probably what it is.

I've got a couple of nights this week where I can sneak some personal garage time, so hopefully I can rip it out.

I didn't think it was possible to pull the lower covers without pulling the mount, but admittedly I've never really tried.


Thanks for the suggestion, that makes sense with the way the tensioner looks like it's "ticking".


paramedick said:
Sure sounds like the timing belt is on the wrong side of the small lower roller. It will make the sound you describe as the teeth of the belt goes over the roller.

Good news, fairly easy to fix. Line everythng back up and lock. Release tension fully on tensioner. Pop the cam sprocket. Pull the harmonic balancer and the lower TB covers. You can get to it to remove the bolt and put the TB on the correct side. If the belt is undamaged, follow the timing belt .pdf to put everything back together correctly.
 

themightyquinn

Well-known member
Joined
Mar 7, 2005
TDI
1999 New Beetle Black
Tore it all apart tonight. Belt was installed correctly. Started the engine with all the covers off. No noise. Started at every stage of reassembly--no noise.

I still haven't put the serp belt on, but everything else is back together and there's still no noise. We'll see if it's something in the accessory drive, but that would piss me off.
 

PDJetta

Top Post Dawg
Joined
Nov 6, 2003
Location
Northern Virginia
TDI
'04 Jetta GLS TDI Pumpe Duce Platinum Grey w/ Leather
gforce1108 said:
Someone else had posted a similar sound when they had the belt around the wrong side of one of the rollers. The toothed side was rolling instead of the smooth side.
I did that on my mom's TDI too, when I replaced her timing belt. Its real easy to do (top roller, I think), but found it on the first strart-up. You have to correct the routing and reset the timing.

Another real easy mistake to make is to turn the tensioner backwards, against the belt. Follow the instructions to the letter and re-check your work!

--Nate
 

paramedick

TDIClub Enthusiast, Vendor
Joined
Jul 29, 2001
Location
Versailles, Kentucky
TDI
2015 Audi Q5 TDI
One other possiblility I've seen once.

On the top metal cover, there are a series of tabs to allow it to mate with the engine. If the teeth are not put in absolutely the correct place, you can get an ugly noise.
 

Boost_virgin

Veteran Member
Joined
Nov 2, 2006
Location
Sullivan MO
TDI
2000 Jetta
I had a whriling sound a few weeks ago right before my serp. belt idler failed. Really strange sound. Since you have not found the sound with the serp. belt on then maybe it's related to that.
 
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