TDI Audi 80: Replace Crankshaft Position Sensor?

Hi.
Before I go any further: I used the search function -- but I didn't become very knowledgeable .

Here's the translation:

'The timing belt on my Audi 80 Avant TDI, manufactured in January 1993, with engine code 1Z, needs to be replaced soon. It goes without saying that the tensioner and other related components will also be replaced. But what about the central bolt for the crankshaft? The previous owner had the timing belt replaced at an Audi dealership in Italy. The invoice does NOT show a new central nut. Thanks to the search function, I now know that the tighter bolts have a ring-shaped protrusion on the bolt head. If, during the replacement, it turns out that the tighter bolt (12. is already installed, does it still need to be replaced, or should it be left untouched? If the 'softer' bolt is still in place, it will definitely be replaced. Did Audi issue a recall for this issue? If so, the crankshaft bolt should have been replaced by then, especially during the last timing belt replacement (at the Audi dealership in Italy), right?'

So: Should you replace a screw if it's hard or not?

Thank you and best regards.
Hermann.

Hello.

'Personally, I would definitely replace that screw!'

The screw has already come loose on mine, and it was already the 'heavy-duty' one that was installed!

Hello,

Is it also a good idea to check the screw between the timing belt replacement intervals?
Perhaps try tightening the screw?

It definitely makes sense to do that, especially if you already know it's a weak point! And checking things never hurts, right?

I probably wouldn't follow up.

Was ist mit Audi? Was ist mit einem Rückruf bezüglich dieses Problems? If so, and if the 'soft' screw is still in use, can one still insist on having this action performed?

Are there any opinions on whether it's advisable to replace a 'hard' screw that might already be installed as part of the belt replacement?

Okay, here's the translation:

Thank you.
Hermann.

[Translating...]http://home.arcor.de/sgrafen/salatoel/kw_schraube/kw_schraube.html

@didl.

I was already familiar with that. Does this work instruction also apply to Audi? Also, this work instruction refers to the soft screws.

I'm concerned about whether a potentially existing, hard, completely solid, and 'non-leaking' screw should also be replaced. The fact that the cost is negligible, at just under 2 Euros, is really secondary. It's not comparable to the cost of a valve, a head of lettuce, or a complete engine failure.

Regards,
Hermann.

Hello,

"There's a 12.8-grade screw in there, and everything seems solid, so I wouldn't do anything. If you absolutely have to remove the washer, do it with the Allen screws. Disassembly won't improve the situation, and either you have sufficient contact pressure, in which case everything will be fine, or you don't. If you don't, it's only a matter of time before something goes wrong."

In Formula 1, they use ultrasound devices to measure the tension of screws even after they've been tightened. Maybe you have good connections with Schumacher or Montoya.

Best regards,
Christian.

palmstrollo wrote:

@didl. I was already familiar with that. Does this work instruction also apply to Audi? Also, this work instruction refers to the soft screws. I'm concerned about whether a potentially existing, hard, completely solid, and "non-leaking" screw should also be replaced. The fact that the cost is negligible, at just under 2 Euros, is really secondary. It's not comparable to the cost of a valve, a head of lettuce, or a complete engine failure. Regards, Hermann

Since the central bolt is a stretch bolt, it should always be replaced.
A stretch bolt is almost always pre-tensioned with a specific torque and then tightened to a specific angle of rotation.

@lofthouse:

While your statement about stretch bolts is technically correct, there is no need to replace the central bolt of the crankshaft pulley during a timing belt replacement. If anything, only the bolt on the camshaft sprocket is usually loosened.

BTW, this is also much easier because even a hobbyist mechanic can achieve the correct torque for this screw, even after a very poor breakfast .

Regards,
Alex.

donalexo wrote:

Even a hobbyist who hasn't had a good breakfast can easily achieve the correct torque for this screw

.

Hi Alex,

Well, I needed a lot of force, and I'm not exactly weak . Even my long 3/4-inch breaker bar from Hazet didn't significantly reduce the required force. Furthermore, the screws that are standardly installed in the VW 3099 tool tend to bend. These also need to be replaced with high-strength 12.9 screws (-> e.g., brake caliper screws).

Simple question: When replacing the timing belt on the 1Z or other four-cylinder engines, can the vibration damper be left in place? On the 5-cylinder engines, it seems it has to be removed, probably because there's a cast-on protective element underneath the pulley. (I haven't done this myself yet).

Since I will soon be facing the issue of timing belt replacement myself: How is it done on the 1Z engine? What steps do I need to perform? I think the tools will be less of a problem, considering what I saw in Dieselmartin's other thread.

Best regards, WarLord.

@Christians
The vibration damper needs to be removed; there's no other way, because otherwise you won't be able to remove the lower part of the timing cover. I'm probably going to get some criticism for this... but if you have a really good 6mm Allen key socket, not some worn-out one, and the 4 screws also look good, then you can use a hammer and an impact driver to easily remove the screws. Unfortunately, the vibration damper itself is quite stuck on the timing sprocket, because the inner part is made of aluminum and the sprocket is made of cast iron – contact corrosion. Caramba and a carefully used pry bar can help.

Best regards,

Dominique.