2000 vw Beetle cam pulley bolt

I recently bought a 2000 vw Beetle tdi with 192K miles. Was running perfect but was due a timing belt change. Took to shop where they replaced the timing belt, rollers, waterpump and serpentine belt. Immediately drove it 100 miles at 65-70 mph, ran perfect and suddenly shut off and died. Upon inspection, timing belt was secure but the lifters were blown and the valves bent. Shop says they did not do anything to loosen the camshaft pully, but upon doing a valve job the machine shop noticed the cam pulley seemed loose and showed the pulley had done some dmg to the cam where it fit into it. There appears to be a small rectanguelar hole (such as where a woodriff? key fits in, but there is no key and the only thing holding pulley to cam is the bolt. Shd there be a "woodriff" key or if not what is the small rectangular hole in the cam for? What could have possibly loosened the pulley? Any insight will help. Shd I replace the pulley or not?

Thanks all...

there is no woodruff key although the slot is there. if the cam bolt wasn't tight enough , it slipped and trashed your valvetrain

They have to be lying about not loosening the cam bolt. This cam sprocket has to come off to do the belt properly and who knows if they replaced the cam seal. Sure sounds like they did not tighten up the cam sprocket bolt sufficiently and it slipped, causing the damage to your head. Seems pretty clear to be a poor workmanship issue. Gurus on this site recommend tightening that cam bolt more than the specified 33 ft pounds. Some recommend 40 ft. pounds or slightly more. Ignore the woodriff key slot. That is not used in these cars.
Now the head has to come off and be rebuilt. I suggest that you talk to Frank Irving (tdi handle: franko6). He is a trustworthy rebuilder of tdi heads and a great source of advice. There may be other damage as well to the pistons. If you can find a decent used engine, that may be cheaper than fixing this one now.
I don't know what your financial recourse is with the mechanic, but please take the car to a trusted tdi mechanic (see the list on this site) for all further repairs or learn how to do the repairs yourself if you are mechanically inclined. You cannot trust "gasser" mechanics to properly maintain or repair these cars.

Don't call it a woodriff key hole as it is not.

It's the lock for manufacturing.

They botched it. Even if they didn't remove it they had the timing far enough off to damage the lifters or the tensioner wasn't in the slot (my bet) as they only go about 50-100 miles before epic failure.

If they didn't take off the cam pully was it anything other than a mark and pray TB installation?

upgefucht timing belt job. Probably mark and pray.

They owe you a head rebuild, cam, lifters, new TB/tensioner, and applicable stretch bolts.

What is the word on cam replacement when the valves crash? If they crashed, the engine stopped so there isn't continual wear on the cam, but does the cam get damaged to the point that it should be replaced? I would guess that it comes down to a trained eye, but generally, what happens?

The cam virtually always receives damage when there is a timing belt skip. If any cam lobes are rounded off, it's trash. Of course the head has to come off and the head needs rebuilt.

The obvious thing... if there is a galled ring on the cam, that is wheretiming was lost. The typical problem is that either dirt or grease was on the cam/ cam sprocket, or the bolt was not properly torqued.

Despite argument to the contrary, 33 ft lbs of torque is comparatively light for a 14mm bolt.
I use 45 ft. lbs. I recommend that to anyone who asks. Using that torque, the sprocket doesn't ever break loose, whereas 33ft lbs. can be risky.

If the bolt for the sprocket was not loosened, the mechanic did not do the job properly. If they didn't tighten the sprocket bolt, they crashed the head. But the bottom line... there is plain evidence that the belt did come loose and it did it very quickly. Galled lines between the cam and cam sprocket is all you need to show.

If they continue to lie to you, you may have to take more aggressive steps.

There is a very good mechanic in your area who knows exactly what I'm talking about. If you want, PM me. I'll see if I can't help you out.

Franko6: Thanks for your reply. Since I was not around when they dismantled the engine to ck the problem, its their word against mine that they never touched the cam sprocket or loosened the bolt. However, the timing belt did not break. Is it possible for them to properly set the time w/o loosening the bolt? If not why? I did order a cam but was unsure if the sprocket was still ok. The cam does have galled lines between the cam and cam sprocket and the bolt did seem as it was not tight enough according to the machine shop that did the valve job. How can I determine if the sprocket has to be replaced? I'm out so much money already that I don't want to replace it unless its absolutely necessary so will trust your answer. My email address is joepaniagua@hotmail.com and my phone # is 210 829-4016.

Again, thanks....

Franko6 said:

The cam virtually always receives damage when there is a timing belt skip. If any cam lobes are rounded off, it's trash. Of course the head has to come off and the head needs rebuilt.

The obvious thing... if there is a galled ring on the cam, that is wheretiming was lost. The typical problem is that either dirt or grease was on the cam/ cam sprocket, or the bolt was not properly torqued.

Despite argument to the contrary, 33 ft lbs of torque is comparatively light for a 14mm bolt.
I use 45 ft. lbs. I recommend that to anyone who asks. Using that torque, the sprocket doesn't ever break loose, whereas 33ft lbs. can be risky.

If the bolt for the sprocket was not loosened, the mechanic did not do the job properly. If they didn't tighten the sprocket bolt, they crashed the head. But the bottom line... there is plain evidence that the belt did come loose and it did it very quickly. Galled lines between the cam and cam sprocket is all you need to show.

If they continue to lie to you, you may have to take more aggressive steps.

There is a very good mechanic in your area who knows exactly what I'm talking about. If you want, PM me. I'll see if I can't help you out.

Click to expand...

What shop?

The reason this sprocket bolt MUST be removed is because there are THREE items which must be in time, crank, cam and injector pump. There is NO WAY to set these three in precise time without having two of the three loose. This way, tension is the same between all three. The two that are loose are the cam and the injector pump.

Once the tensioner is set, the tension is uniform all around. Then the cam sprocket is locked with the bolt and the IP is locked with the three bolts on ir. Now the cam locking plate and injector locking pin can be removed, leaving these in nearly perfect time. The IP is fine tuned later.

Since they said they didn't loosen the cam sprocket bolt, they botched the TB job by NOT loosening and removing the pulley. This ensured the valve timing was WRONG. That it started means they got the IP timing correct which means the cam timing WAS OFF. When the pistons smacked the valves enough, something HAD to give and that was the cam sprocket. It slipped but not enough to save the system

Conceivebly the engine could be in time, valve wise, if the cam sprocket is not loosened, but the chance of this is pretty slim. Conceivebly the shop person could have installed the new belt and used the cam lock plate and everything was properly lined up and he did not have to break the cam sprocket nut loose. But....the proper procedure calls for breaking the cam sprocket loose and setting the timing, using the cam lock plate, after the new belt and other parts are installed. I would take in a copy of the Bentley manual that covers this. If the shop owner/mechanic argues that they did not break the nut loose, you will know that they DID NOT follow the procedure to begin with, since Bently calls for the cam bolt to be loosened.

Its obvious that its a botched timing belt job, most likely from an improperly tightened bolt.

Also, did they replace AND TORQUE CORRECTLY the motor mount bolts? If not, in a year or so these could fail, and that's harder to prove since its not an immediate failure.

Go back with the Bentley manual, review the procedure with them, and demand that they redo the job with a rebuilt head. You may want to supply the rebuilt head at their expense.

If they do not agree, it may be time to file a claim in court. The $ amount may be more than the limit for small claims court. This may place the case in civil or circuit court. The Clerk can tell you. Find out the rules from your Clerk of the Court. Its easy to go pro se (representing yourself) in court. No attorney needed. Just get the Rules of the Court and follow them.

--Nate

Time to call a lawyer and consult some people that know TDI's in the area.

They F'd up and now their insurance can pay for it.

I'm on this one. Contacted the OP, will visit the shop tomorrow to advise and assist in retiming the engine. Hopefully they haven't installed the head, sequence of operations is critical when dropping a head. Set crank at TDC, then counterclockwise about 45 degrees so pistons are down. Lock cam at TDC, install head. Rotate crank back to TDC and lock. Lock IP hub, loosen sprocket bolts. Install belt per PDF, Voila. And that is just from memory.

Yes, I have done this several times, along with head replacement. Yes, I have the tools (cam and IP locking devices) along with VCDS and the Bentley. Last TB I did was on the money from the get-go,

EDIT:

No call today. Unless the mechanic gets smart, sounds like a 2000 TDI NB will be needing a new engine. I sense it is pride keeping my phone silent. Too bad. Rod East, the one dealer capable of doing the job right, only charges about $1400 for a complete TB replacement.

Joseph -

I don't know why Keith is not hearing back from anyone, but I do encourage you to make sure he is involved in any further work on the engine at the shop where they botched the timing belt job. He knows what he is talking about

hey guys, I did my tb on my 98 nb 3 months ago. I did much studying, and invested in tools & vcds. my question is I torqued my cam bolt to 33 lbs ft. should I retorque to 45 lbsft as franko6 says?
the car runs great, and timing right on as per vcds. thanks to all the great gurus info and experince. thanks again to all
newbie , mow

it does not hurt to tighten it a bit more. I know the early watercooled required you to change the fat washer behind the bolt everytime you undid the cam bolt. But those had a woodruff key .

mow said:

hey guys, I did my tb on my 98 nb 3 months ago. I did much studying, and invested in tools & vcds. my question is I torqued my cam bolt to 33 lbs ft. should I retorque to 45 lbsft as franko6 says?
the car runs great, and timing right on as per vcds. thanks to all the great gurus info and experince. thanks again to all
newbie , mow

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Sure, just make sure to properly counterhold the sprocket. I do not like the idea of turning over the engine through the cam as it places a lot of stress on the tensioner.

The torque value is enough when the cam and sprocket are new but the layer of oxidation that builds could reduce the friction, making it more prone to slip.

If it hasn't moved it's fine. Don't mess with it.

33 ft-lbs on a tapered fit is a LOT OF CLAMPING FORCE, leave it alone.

DB

Googling Conical fit comes up with references to this as the first few results: "The conical fit approach to modeling ionospheric total electron content"

"Taper fit" on the other hand mostly references mating surfaces.

A taper is a cone though so it could be used interchangeably, but out of context it may cause confusion.

Drivbiwire said:

33 ft-lbs on a conical fit is a LOT OF CLAMPING FORCE, leave it alone.

DB

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Sure thing. But some think it can turn as they look to this as the root cause of timing belt mishaps. Well, it is my belief that there is slippage ex post facto.

In this case, it sounds like the mechanic is heading towards another failure and then I might be called.

Even the Haynes manual covers removal of the cam sprocket. I only wonder what manual they are following.

whitedog said:

Googling Conical fit comes up with references to this as the first few results: "The conical fit approach to modeling ionospheric total electron content"

"Taper fit" on the other hand mostly references mating surfaces.

A taper is a cone though so it could be used interchangeably, but out of context it may cause confusion.

Click to expand...

Morse Taper is used on many machine tools, like drill presses. But some have a secondary key on the end of the shaft to prevent torsional slippage. Also look under "machine taper"

Keith_J said:

Morse Taper is used on many machine tools, like drill presses. But some have a secondary key on the end of the shaft to prevent torsional slippage. Also look under "machine taper"

Click to expand...

There are lots of different tapers with Morse being the most widely known. It has a taper of 5/8 inch to the foot. Others are different.

I <3 Google.

No Way

Quote

They have to be lying about not loosening the cam bolt. This cam sprocket has to come off to do the belt properly and who knows if they replaced the cam seal. Sure sounds like they did not tighten up the cam sprocket bolt sufficiently and it slipped, causing the damage to your head.
End Quote



The pully has to come off. Period. They are ripping you a big one.

Just replaced one yesterday, and another one 4 weeks ago, it aint possible. Torque all bolts to vw specification, and they won't come off, too tight, could break, too loose, could come out.

The cam bolt is not a streach bolt, so it is reusable.

But remember most of the bolts usually sort of aqua color to them, are one time use streatch bolts and if you reuse them they will break.

sullyTDI said:

Quote

They have to be lying about not loosening the cam bolt. This cam sprocket has to come off to do the belt properly and who knows if they replaced the cam seal. Sure sounds like they did not tighten up the cam sprocket bolt sufficiently and it slipped, causing the damage to your head.
End Quote



The pully has to come off. Period. They are ripping you a big one.

Just replaced one yesterday, and another one 4 weeks ago, it aint possible. Torque all bolts to vw specification, and they won't come off, too tight, could break, too loose, could come out.

The cam bolt is not a streach bolt, so it is reusable.

But remember most of the bolts usually sort of aqua color to them, are one time use streatch bolts and if you reuse them they will break.

Click to expand...

That color is part of the anti-corrosion coating given to the bolts instead of cadmium (toxic) or chromated zinc (still Zn but no Cr as hexavalent Cr is bad juju). It does not signify TTY fasteners. In fact, only the material properties AND METHOD OF INSTALLATION signify TTY fasteners.

Rod bolts on these engines are TTY but they also function as dowel pins, having precision machined swellings near the head.

In case Joe is lurking, this is the procedure:http://pics.tdiclub.com/pdf/a4timingbelt.pdf

Keith_J said:

That color is part of the anti-corrosion coating given to the bolts instead of cadmium (toxic) or chromated zinc (still Zn but no Cr as hexavalent Cr is bad juju). It does not signify TTY fasteners. In fact, only the material properties AND METHOD OF INSTALLATION signify TTY fasteners.

Rod bolts on these engines are TTY but they also function as dowel pins, having precision machined swellings near the head.

Click to expand...

And don't let me get started on the misnomer "Stretch bolts".

Heh... I always know that I go "flame on" when I say 45 ft lbs.

Just to make myself very clear...

1) The ALH motor is the lowest torque setting for a taper-fit shaft of all the diesel engines made by VW
2) If the shaft is put together correctly, 33 ft lbs is enough... but it's too c close to being not enough.
3) If you use 45 ft lbs, no damage is done. Nor is any noticeable extra effort required to remove the cam sprocket when it is needed off.

Actually, just for kicks, I put 150 ft lbs of torque on a junk shaft, sprocket and bolt. I could see no fracturing on the sprocket, damage to the threads in the cam or bolt, nor was there any problem removing the sprocket. I think VAG is testing the lower limits of what the sprocket should have as a torque value. Simply on general theory, a 14mm bolt should have more torque.
4) Just because a book says so, is no reason to live by blind faith. Sometimes to ask "Why?" is a good thing.
5) It only takes ONE TIME... and then, you are a believer. Do it 1000 times with no problem, and once wrong... you'll always remember the one that went wrong.

Isn't that the way you'd see it, Joseph?

I'm with you Frank. I did 45 ft-lbs on mine and it felt MUCH better than 33 ft-lbs. It definitely increases the fudge factor for variances in torque wrench accuracy and any other possibilities for slippage. 33 ft-lbs loosens way too easily when you go to remove it, you could easily pop that bolt loose with a short 3/8" ratchet.

Dimitri16V said:

it does not hurt to tighten it a bit more. I know the early watercooled required you to change the fat washer behind the bolt everytime you undid the cam bolt. But those had a woodruff key .

Click to expand...

Not the same.

And the washer isn't removeable.

Back to the original topic: you know this happens ALL THE TIME. Botched timing belt jobs. Just think, what, every few weeks there is a new post that is essentially the same?

It is truly amazing how many stupid people there are with tools, it really is. Bottom line: the installer botched the timing belt job. Period. And if they insist they never loosened that bolt, that is 100% admission of doing the job improperly!!! M&P indeed.

Also, the machine shop that looked at the head clearly has no business working on a VAG diesel, because if they did they would KNOW that keyway is for camshaft manufacture and NOT engine assembly.

So now you have a double whammy. A shop that should never have laid a tool to the car, and a machine shop that should never have touched a VAG cylinder head.

You need to get that car, whatever is left of it, out of that place and to someone who actually KNOWS what they are doing, before it has become tooefed beyond all recognition!!!!

Just think, those clowns will be reusing the stretch bolts again!!!