Timing Belt Tensioner Failure - Installer Error

Benjamis

Veteran Member
Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
It slipped out and it bent and is a little twisted now. But surely a drop of oil wouldn't be enough to do that. The oil residue is from the valve cover leaking because the mechanic I will tell you about did not put it on properly, but I have since fixed it.

I paid dearly for a timing belt job 17,500 miles ago by an untrusted mechanic before I had any idea what I was doing, and was traveling around and sleeping in the back, had minimal tools, nowhere to work on it, etc. The shop I towed it to was the erroneously named Volksmasters in Hialeah, FL, who said they could work on TDIs, and that is a whole story altogether that I might post a thread about one day to vent. They threw parts at it without my authorization and required a payment of over $1200 just to diagnose a 'stretched timing belt hanging on by threads'. I knew I was getting screwed over and didn't know what to do about it. The tensioner was purchased from Hans Auto Parts, which I regrettably Ok'd. I have come to know better through this forum and have a place now and the tools to work on it. I had the Bentley all along and now have VCDS. I tooled away on this most of the winter after some broken flywheel bolts, and it was running like a dream, better than I ever knew it could run, with raw power to boot... but I only made it 700 miles for this to happen.

I had very occasional misfires that I started noticing last year actually, but they went away so I thought it was just from wiggling some old wires around or something. I have tygon fuel lines so know it's getting fuel. But then I started feeling the misfires again a couple weeks ago, and have been searching for vacuum leaks in my free time with minimal success. It otherwise ran very well with great power. Then the other day, I was revving up and in 3rd gear and it suddenly puttered and blew a ton of smoke on the person behind me. I took it very easy getting home and it did ok, and right before coasting to my driveway, I hit the gas, curious if the misfires and puttering were only while revving. It immediately cut out, and I coasted into the driveway. I cranked it for a couple seconds hoping to move it to the proper parking spot, but knew by the sound it wasn't going to start, and haven't cranked since.

First thing I did was pull the timing belt cover. The tensioner still springs but the tab is out and won't go back in. But why would it come out in the first place? The notch it goes in looks to be in good shape. The nut is torqued to 15-17 lb. Just a piece of crap? I don't drive hard, no mods, no redlining, just economical point A to B.

I pulled the valve cover and the cam and crank are still in proper mechanical alignment, no cracked lifters, and I can push the tab back to where the notch is and get temporary tension on the belt again, and hand cranked several revolutions and there is no indication of internal damage. Only the injection pump sprocket skipped a couple teeth. When it cut out, it was dead silence, no clank. I have clanked before, but not this time. Lucky me, maybe, if you want to call it that. I suppose I need to do a timing belt job and do it right.

Any insights on tab slippage?
 

Nuje

Top Post Dawg
Joined
Feb 11, 2005
Location
Island near Vancouver
TDI
2015 Sportwagen; Golf GLS 2002 (swap from 2L gas); 2016 A3 e-tron
Tab made out of the cheapest pot metal the foundry in China could get away with calling "metal".
Hans Auto Parts / Prothe / Rothenbacher / whatever you call him...I mean, seriously **** that guy.
 

Benjamis

Veteran Member
Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
Tab made out of the cheapest pot metal the foundry in China could get away with calling "metal".
Hans Auto Parts / Prothe / Rothenbacher / whatever you call him...I mean, seriously **** that guy.
Sounds about right. I didn't want to immediately jump to conclusions, but... yea.
 

Benjamis

Veteran Member
Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
"Understatement of 2021" award winner.

Disconnect the battery (so nobody tries to borrow your car to charge their dead battery), buy a new Litens tensioner, (probably a whole kit, assuming the belt and roller also came from Rottenheimer), and redo the job.
I've had a lot of bad luck with this car but also quite the opposite. I avoided a tow this time around and most likely catastrophic engine damage that might have pushed me to buy a new car and not have to spend my days working on this one. Ha. Labor of love, they say. Or... labor of complete idiocy. Haha.

Yea I know now to disconnect the battery but in my case just because there is some sort of small draw I have not pinpointed yet. The belt is Contitech and is in good shape and the roller was not replaced and might even be original. I'll replace all in this case.
 

Mongler98

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Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Imo I think it wasn't installed correctly.
The threads on that post that the 10mm nut that holds that down are very few. Every belt jibe I have ever done on these will have a few more threads showing past the end of the nut than what you have there.
Those tabs are not robust at all even for quality ones. I have had 2 bent on arrival and I'd just bend it strait. Never been an issue and one of those was on my car too.
I would not jump to concussion to say that it was defective yet.
Not until you pull it off and inspect the seat that arm is supposed to be in.
Measure the stick out of those threads and straiten the arm and put it back to confirm it was I stalled correctly.
Still
Another one bites the dust?
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
Once the nut is torqued the tab does absolutely nothing. If it was in that position after running the engine it was there when it was installed or the nut loosened up. Or maybe never torqued though I'm not sure it could end up there even if it were loose.

I agree with Mongler. I think it was installed there by someone who was inattentive or didn't know better.
 

Abacus

That helpful B4 guy
Joined
Nov 10, 2007
Location
Relocated from Maine to Dewey, AZ
TDI
Only the B4V left
It was installed backwards, and that is exactly what can happen when it's installed properly. The half moon should be on the top, this one is on the bottom. It was tensioned CCW like the gasser VW engines rather than CW the TDI needs. If the tensioner says "Litens" on it, then it's a good one. Odds are very good that if they bought it from Prothe/Rothenbacher/Hans Auto then it's absolute junk, but it wasn't the cause here. ANY shop that uses parts from that crook shouldn't be in business.

This is the proper tensioner orientation.





Check for the manufacture date on it, sometimes these "experts" like to reuse parts since they claim they're not needed for a TB replacement. The date code is embossed on the front but you'll need a mirror to see it. It'll look like this:



Turned around the proper way it reads "50/99", which is the 50th week of 1999.




I once worked on an older gentleman's TDI and it started hard. I told him the timing was out and that I could fix it for him. He said he just had another timing belt replaced by a "VW Only" garage. When I put the Vag-Com on it the timing didn't even show up on the graph. When looking things over, the tensioner was original to the car, which had 138,000 miles on it. The first was done by the dealership and the second by this expert garage. He bought another tensioner and roller and I installed them for free. He said the car never ran so good.


Here is another one that I caught before it did any damage.





Oh, and the back of your tensioner will probably look like this, which is what happens when they're tensioned backwards. The tensioner spring is only designed for one direction, so when tensioned backwards it's against the stop and not the spring. It then hammers itself to the failure point but before that it'll allow the engine to keep time.




And the oil doesn't matter, I've worked on some atrocious motors that were covered in oil and there was no issue to any component.




So what you have to do now is determine if there is any damage to the head from the tensioner letting go. I would pull the valve cover and rotate the engine BY HAND and feel for any signs of hitting. Then I would pull the cam, since the timing belt needs to come off anyway, and inspect the lifters for cracking. Since the diesel engine is an interference engine, if there was valve to piston contact you *should* see cracking on the lifters. If some is found, you need a new head or to have that one reworked (by someone reputable, like Franko6). If none is found, my recommendation is to pull the head and look for signs of hitting on the piston tops (you could use a very small borescope for this as well), but you may just install the timing belt and new components. If the engine wasn't that far out of time then you may have gotten it early with no damage. But, if there was damage and you didn't see it, then engine will last from 5,000 to 10,000 miles and then eat itself from a dropped valve. It's happened many times before. The valves on these are in line with the pistons, so they don't bend, they shrink. So the valves don't hang up like a gas engine when they are bent, but in time the fatigue from the deformation will cause it to snap, drop into the piston, and then you'll need a whole new engine rather than just a head.

Whatever you do, do not go back to that shop and you may want to pursue legal action depending on what you find.
 
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Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
yea i think it might be backwards. When i took my tensioner off just enough to remove the tentino but not the belt to swap a failed seal ... it looks like the tension part is rotated all the way down. is it possible to install them upside down or backwards? So your saying it was mentioned in the wrong direction going counterclockwise?
also no way its from any oil leaking... i had that problem and let me tell you, it ain't going to cause it to slip out..
looking back as this old picture you can see how when the tension is fully removed all the way that the moon is towards the firewall when it should be on top. when tensioned it MUST be on top. not the bottom. and i was wrong about how many threads show past, definitely that one is tight as tight gets so it was definitely tensioned WRONG. this is an install error. that OR something dropped into the belt and JAMMED it up and caused it to force the arm out of its home!
a full inspection will reveal the truth.



If you follow this guide... https://www.myturbodiesel.com/d2/1000q/a3b4/w-jetta-passat-tdi-timing-belt-replacement-install.htm

you will clearly notice how this was installed WRONG so... yea, installer error caused this 100%
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
You're very fortunate that the damage was only superficial, and that you get to throw away that Hans tensioner that isn't worth anything.

As others have said, mostly like it was tensioned backwards (CCW). It's the first thing I look for on inspections anymore because it seems to be so common to the uninitiated mechanic.

I'm also curious about the brand of tensioner the mechanic used. I'm a big advocate for Litens or repackaged versions of Litens tensioners (Conti or SKF or INA) or a German made alternate brand. While we know it came from Prothe (Hans et al) there are other brands now repackaging Chinese tensioners and with the laws regarding product origin now almost gone you can never be sure of where it comes from.

I doubt that the base material on that tensioner is pot metal, it looks to be stamped steel like most all other tensioners out there, but it's the quality of and thickness of the metal used that matters most with these, well and you have to tension it in the proper direction too!!

You'll probably never get any satisfaction out of the mechanic who did the work and fleeced you, but it was your good fortune that day to come away from this with a salvageable engine IMO.

Good luck and post up your story about the FL shop, everyone should know about the good and bad out there, and where to avoid!!!!

Steve
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
Tensioned forward or backward wouldn't matter with respect to the tab being where it is. How did the tab end up where it is?

Was the nut still tight? It wouldn't move otherwise. Since there are no apparent scratches on the dust shield it didn't

I think it was installed with the tab where it is, which is why it was bent since there's no hole for it, then tensioned. Maybe backward, maybe not but either way there probably isn't enough travel for it to get it tight enough and the belt finally slipped.
 

Benjamis

Veteran Member
Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
The tab left a scratch all the way from the alignment hole to where it is in the pictures. You can see the scratch in the pictures, and I made sure I took the pictures before messing around with anything. I think it was installed in the alignment notch properly.

The fact that the tab moved clockwise from the alignment notch suggests that it was tensioned CCW. If I push the tab back CCW towards the notch, it builds tension.

If I hand crank the engine, the tab wants to move CW and lose tension.

When I first went to hand crank, I heard some clanking and had some moments where I thought the head was toast, but then realized it was the tensioner jiggling and making noises. If the tensioner tab moves CW to it's location in the pictures, the belt can get a bit slack and I almost skipped a tooth on the injection pump while hand cranking, but found out I can push the tab back CCW to somewhat tension it, and hand crank another stroke before the tab moves CW and the belt loses tension again. The tab is too bent to pop back in to the alignment hole.

I would have been very surprised if that tab was holding the whole car together essentially. Surely like you said, it is just there for alignment and to counterhold for tensioning, and once the bolt is on, the torque holds it down. But clearly something is amiss, and I will have to pull it off and inspect it and report back, but this all happened on a very busy week and weekend so might not get to it for a bit. Luckily I have a backup vehicle.

I checked the torque on the nut and it is at about 17 lbs, so that wasn't the problem.
 

Benjamis

Veteran Member
Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
my recommendation is to pull the head and look for signs of hitting on the piston tops
What do you think the chances are of that happening if the cam and crank are still perfectly in time? Only the injection pump is off by 2 or maybe 3 teeth.

As I mentioned I have hand cranked several revolutions, and it's hard to tell with the tensioner making noise, but I feel no issues while cranking. I see no cracked lifters but like you say I should probably take the cam off to see them in their entirety.
 

Benjamis

Veteran Member
Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
Whatever you do, do not go back to that shop and you may want to pursue legal action depending on what you find.
No chance I would go back there, plus I'm about 1500 miles away now. Even before this happened, I have thought of legal action. I guess it wasn't a complete disaster, they got it running again, but they nearly destroyed it a few times already, I will post the story soon.

Any recommendations on how to pursue legal action?
 

Benjamis

Veteran Member
Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
I confess and take the blame for the Hans parts, not the erroneously named Volksmasters shop. They were charging an arm and a leg for parts, and I was helping them search for parts that day and found Hans while google searching and asked him if he ever ordered from Hans and he said he never heard of them, so we tried it out. He said the parts looked of acceptable quality when they arrived, maybe just not polished up like OEM. I was very low on funds and had my mobile bed taken away from me for a month and a half in a place where I didn't know anyone at all. I was broke after this, I nearly ditched the car a few times so I didn't have to pay for it. But... it's just too good of a car, which is why we're all here.
 

turbodieseldyke

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Joined
Jun 6, 2010
Location
Free Mustache Rides
TDI
98 jetta
I don't see the point of legal action 1500 miles away. What could you hope to recover, besides towing fees and the cost of a new tensioner?

I revise my previous advice. You should buy a new belt too, since this one slipped and let the IP get out of sync. That may have weakened some teeth, which could strip off before its scheduled replacement.
 

Benjamis

Veteran Member
Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
So here she is:


Looks like a drunk man aligned that one. The metal arm popping out or being pushed back in does not affect the alignment notches.


No other markings on the tensioner front or back except 6007RS


Bent arm wore away the shoulder half way.


Shoulder wear. No sign of belt wear from what I can see.



The bottom lip has slightly begun to burrow into the retainer. No other apparent damage.
 
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Benjamis

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Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k




So I'm going to venture to say that not only was this tensed CCW, but it was overtensioned as there is a little gouge on the left side of the notch. The overtensioning pre-bent the arm, leading to the eventual pop-out.

After they did the timing belt job, I got the call and they said it was 'seized up'. They ended up replacing the lifters. They said they were all gunked up (but didn't notice while doing the timing belt of course). So I would venture to say that they tensed it up way too tight and could not get it aligned properly since they were going backwards. I read on another thread somewhere that on overtensed belt can sieze up the lifters somehow. So when they replaced the lifters (if they did), they retensioned not as tense, so then they could turn the crank. That's my guess, and it wouldn't surprise me, because they also tensioned the accessory belt as tight as they possibly could which led to my water pump going out on the highway in the middle of nowhere 500 miles later.

I have .013" play in the intermediate shaft, side to side. Nearly zero up and down play. I pulled the shaft out and saw the bearing, it is still in tact but there is minor pitting and it is discolored and looks like it is on it's way out. Bummer I just had the tranny off 700 miles ago. Anyway, how much play is too much play on the intermediate shaft? I'm sure an overtensed belt didn't help it at all.
 

Benjamis

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Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
After I cleaned it up, I went ahead and put the tensioner back on. I was able to get it off without removing the belt, so I put it back on and tried tensioning it CW, and couldn't get the alignment notches to line up. When I de-tensioned then tried retensioning again, the notches were in a different position than before, and it was like it was 180 degrees off, so something is very wrong with it now, I'll have to take it apart one day. I just wanted to see and also practice for my first timing belt job. I'll be happy to get proper new parts and be done with all of that. Sorry guys, about ordering from Hans. New guy, ya know. I never worked on cars before. I'm mechanically inclined, but my first car was a Chevy Aveo that I bought brand new for 7500 back when you could still do that, and I drove it 140k without having to do any major work. I changed my oil and brakes and plugs and wires and what not, and she never let me down, and I took it where no Aveos have ever gone. The only reason I got rid of it was because I briefly lived in CA and couldn't get it smogged without a new CARB converter for around $2k, so I read up a bit, and bought a VW Rabbit, then another, then found the B4V, and the rest is history.
 
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Abacus

That helpful B4 guy
Joined
Nov 10, 2007
Location
Relocated from Maine to Dewey, AZ
TDI
Only the B4V left
That'd be the 32nd week of 2012, but that tensioner is one I have never seen before.

Ugh, so they replaced the lifters? Damn. Without the cam? What about the lifters breaking-in? What the hell went on! If I had a flat tire I wouldn't let them put air in it.

No worries on ordering parts from Hans, you didn't know any better. I just hope they didn't completely mess up the engine, or the idiots working on it.

The only thing I can say is that you have 2 options: 1) is to pull the head and send it out for a rebuild or at the very least a check, or 2) drive the car and hope it's not a time bomb waiting to self destruct. Option 3 is to have someone reputable look at the car but they aren't going to be able to tell very much without tearing it down. Either way, I'd be doing my own work on my own car from now on. They're pretty easy to work on and it doesn't cost that much. That is, if you have the availability to work on your own car, some locations don't allow it. A Bentley Manual for the B4 is a worthwhile investment, and a Vag-Com is a must.
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
I'd replace the stud too. You prolly intended to but...

Inspect the threads in the hole carefully. Make sure they threads in the head can take the torque. If you're sending it out for work maybe have them install their favorite insert just in case.

You prolly already agree with this but the belt didn't do anything to the lifters unless they mistimed it. Then it wasn't really the belt.

As Abacus alluded to, was the cam changed? Prolly not. One wonders if the lifters came from the same place as the tensioner. A whole set with the cam from a reputable vendor isn't too much.

About the tensioner landing in a different spot, was the sprocket loose and the pump unpinned as it should be for tensioning? Maybe the belt wasn't fully seated the first time? Oh, was it the same tensioner? If so I wouldn't worry about what it's doing.
 

Benjamis

Veteran Member
Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
I bought this car almost 4 years ago and bought the Bentley shortly after. I finally got the ross-tech cable this past winter. I would agree that working on this car is indeed fairly easy once you know what you are doing. And after my experience taking it to that mechanic, I will never take it to a mechanic again.

They said they replaced the lifters, but if they actually did or not is something I will never know. They definitely didn't replace the cam, or I would have been billed for it. I really don't know what to believe from them though. I had never pulled the valve cover before, so don't know what the lifters looked like. But now, they do look in pretty new condition. No cracks.

pull the head
Just wondering, if the cam and crank are still perfectly lined up, how could there be engine damage? Could it have skipped teeth, then skipped back to perfect alignment after it hit a valve? What are the odds?
 

Benjamis

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Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
That is, if you have the availability to work on your own car, some locations don't allow it.
You mean, if you live in a city or something? I didn't know there are places you can't work on cars. I guess it would make sense in a city with street parking. I'm glad to be living out in the country and have access to any tools and can more or less do what I want.
 

Benjamis

Veteran Member
Joined
Jan 17, 2021
Location
Due east of Cincinnati, Ohio
TDI
1996 B4V 1Z 318k
About the tensioner landing in a different spot, was the sprocket loose and the pump unpinned as it should be for tensioning? Maybe the belt wasn't fully seated the first time? Oh, was it the same tensioner? If so I wouldn't worry about what it's doing.
This I will never know. The mechanic won't respond to me ever since I let him know what he did wrong. He doesn't stand behind is work and is easily offended.
 
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