Timing Belt Replacement Tips & Intake Manifold Sludge

Hello,

I had promised some time ago to report back after I had performed the timing belt replacement on my A3 with the AHF engine.
According to the workshop, the recommended interval for replacing the timing belt on my engine is 60,000 km.
Since the improved version of the timing belt was already installed during the first service at the workshop, I have decided to postpone the second replacement for a bit.

It was changed after 79,000 km; I didn't dare to wait for the full 90,000 km because I couldn't find the invoice from the first change and I wasn't sure whether any rollers had already been replaced.

After a total of 139,000 km, I decided to go with the CT946 K2 timing belt kit from Continental, and a new water pump (genuine VW/Audi replacement part) was also installed as a preventative measure.

Conclusion:
- The old timing belt still looks very good visually. Its width (24.7 mm) is close to the original specification.
- Condition of the tensioner and guide rollers is excellent.
"No signs of bearing play are visible, with only a minimal amount present in the large roller bearing."
- Water pump appears to be in good condition visually, with no noticeable bearing play.

"It is highly likely that the parts would have lasted longer than the estimated 90,000 km maintenance interval."
However, the good condition is likely also partly due to the predominantly long-distance operation of my vehicle (constant engine speeds of approximately 3200 min ^-1 ).
After the replacement, the start of injection was still within the tolerance range and did not need to be adjusted.

Since my EGR valve has been defective for about 82,000 km, I wanted to check the condition of the intake manifold after driving 57,000 km without the EGR system functioning. I had already performed a rough cleaning at 82,000 km.

Conclusion:
- The inside of the pipes is slightly oily but clean.
- virtually no tar-like residue is visible anymore, even on the areas of the intake manifold that were not cleaned.

Here are some time-saving tips for the end:
The cylinder head cover and the camshaft sprocket do not need to be removed.
Once the vacuum pump is detached from the cylinder head, you can fabricate a suitable T-shaped steel profile to lock the camshaft in place.

The camshaft wheel does not necessarily have to be removed if you exercise some care and feel when installing the new timing belt.
If you place the timing belt at an angle, with 50% of it on the injection pump pulley, and then pre-tension it slightly by rotating the crankshaft (a tip from haehnlein), you can simultaneously slide both the tensioner roller and the belt diagonally onto the camshaft gear. After that, simply push the tab of the tensioner roller into its slot using a screwdriver.

"Those hose clamps on the air intake pipes are a real pain. I wasted quite a bit of time trying to install them with pliers."
I have now replaced the hose clamp on the connection between the intercooler and the charge air pipe to the engine with a standard stainless steel hose clamp. I also replaced the clamp on the rubber hose of the turbocharger to the plastic pipe of the intercooler.

Money-saving tip:
The engine support can be replaced with an L-shaped wooden profile (dimensions: 12.5 cm / 9 cm side lengths, width matching the oil pan, board thickness 3 cm) that rests against the rear of the engine block and the oil pan.
The oil pan only prevents the wooden profile from tipping; force is only transmitted through the block.
Two wood screws prevent the profile from slipping off the engine block and extend into corresponding holes in the block.
Then you can conveniently use the jack to raise or lower the engine, which was necessary several times.

Best regards, Rainer.

Rainer K. wrote:

Since my EGR valve has been defective for about 82,000 km, I wanted to check the condition of the intake manifold after driving 57,000 km without the EGR system functioning. I had already performed a rough cleaning at 82,000 km. Conclusion: - The inside of the pipes is slightly oily but clean. - virtually no tar-like residue is visible anymore, even on the areas of the intake manifold that were not cleaned.

Hi Rainer,

That's actually quite pleasant... What was the consistency of the black sludge at 82,000 km? Was it still wet and sticky, or already dry and crumbly?

Quote:

The camshaft wheel does not necessarily have to be removed if you exercise some care when installing the new timing belt. If you place the timing belt at an angle, with 50% on the injection pump pulley (a tip from haehnlein), and pre-tension it slightly by rotating the crankshaft, you can simultaneously slide both the tensioner roller and the belt diagonally onto the camshaft gear. Then, simply push the tab of the tensioner roller into its slot using a screwdriver.

Also, some good news regarding making things easier. I hope this also works for the older 1Z/AFN generation with its more "primitive" belt system...

It is said that the rear wheel must also be removed because each belt has a slightly different length, and without rear wheel alignment, the motor control will no longer function correctly.
Is your control system noticeably "off" now?

Hello Rainer!
Your suggestion to use a custom-made steel profile in the shape of a "T" as a replacement for the adjustment gauge sounds appealing.
Can you describe the dimensions in more detail? A small technical drawing would certainly be very helpful!
Is the same tool (part number of the locking bar) used for all VAG TDI variants (1Z, AGR, AFN, ALH, etc.), or are there engine-specific variations even here?

Thank you for the information.

Regards,
Alex.

Hi,

There is an original VW ruler that can be installed instead of the tandem pump.
is being installed. I had it done at my trusted Volkswagen service center this week.
saw it, but didn't have time to 'take it in.'
It has a horizontal pin that engages with the camshaft hub.
und 2 außermittig liegende Bohrungen für 2 Schrauben. SJust hold it.
Open the valve cover and proceed with the work.

Best regards,
Stefan

Hi,

Ulf wrote:

That's actually quite pleasant... What was the consistency of the black sludge at 82,000 km? Still wet and sticky, or already dry and crumbly?

If I remember correctly, it was damp and sticky in the intake manifold, about like grease at 5°C. I managed to remove it with my fingernail . Around the plate of the EGR valve, it was drier and harder; I had to really scrape it off.

Ulf wrote:

It is said that the rear wheel must also be removed because each belt has a slightly different length, and without rear wheel adjustment, the motor control will no longer function correctly. Is your control now noticeably "off"?

You can't notice anything about the camshaft, and the start of injection has shifted slightly towards "earlier," but it's still within the acceptable tolerance range.
Therefore, I didn't adjust anything there. I think the changes in belt lengths will probably only be within the range of homeopathic doses, and adjustments will really only be necessary if you have to remove all those parts.

StevieB wrote:

...there is an original VW ruler that can be installed instead of the tandem pump. is being installed. I had it done at my trusted Volkswagen service center this week. saw it, but didn't have time to "take it in." It has a horizontal pin that engages with the camshaft hub. und 2 außermittig liegende Bohrungen für 2 Schrauben. SJust hold it. Open the valve cover.

Mine looks almost the same, except that I didn't include the two screw holders on the right and left sides.
With the length of my steel profile being 135mm, you can actually tell by eye whether the camshaft groove is parallel to the cylinder head, unless you have a distortion in your vision.
The depth of the "nose" into the camshaft groove is 15mm. I don't have the other dimensions memorized, but I can provide them if you like, although it will take some time.
Someone might also be able to take a picture of the VW part, as I am now 180 km away from my workshop.

Best regards, Rainer.

Here's a photo of my (recreated rulers).

I had them made for the JP back then, but the dimensions also needed to fit the 1Z.

The round thing is the pump spindle.

Great quality... I really should have gone with the VW parts or those cheap AHDEU ones instead.

The bearing of the idler pulley in my Conti kit has disintegrated. After 50,000 km, it was more than worn out.
Now I can look around and figure out where and how to get one of those things, since driving isn't an option anymore.

'50,000 km is really nothing! On my old car, I didn't replace them until 210,000 km. Of course, they were completely worn out by then.'

Hi Rainer,

I hope the engine is still in good condition.
Have you found the missing bearings from the timing belt system? This leads me to a question about warranty coverage for consequential damages. If the timing belt now skips due to an extremely worn idler pulley (which should still be under warranty) and the engine fails as a result, how does that affect claims for compensation?

Hi Rainer!

My condolences for your unpleasant surprise.

What I'm interested in knowing, especially for preventative purposes: How did you notice the damage? Did the problem appear suddenly or gradually?
Certainly, there was also an accompanying sound. How would you best describe it?

All readers would certainly appreciate a detailed explanation, so that anyone (hopefully no one) who finds themselves in a similar situation doesn't have to turn off the engine only when it's too late.

Regards,
Alex.

Hi.

"@Marco: It looks like all the pellets are still inside, but the guide cage and cover disc have crumbled. Hopefully, nothing else has fallen in besides a small piece of plastic from the guide cage."
@donalexo: Heading home from work. Drove past a junction about 500 meters from my place. An old Opel was next to me. *Sound of squealing tires*: "Screech-screech-squeal-screech-screech."
My head: "Not another one" .
The Opel is driving away - the noise remains.
Nothing was noticed before or this morning. However, during the last timing belt inspection, I noticed that the roller had a "rough" feel. It wasn't smooth like you would expect from a ball bearing, but it also didn't rattle or seize.

Damn, today I wanted to finish the flooring in the attic. Again, nothing got done. Because of that, I have to quickly get a new roll tomorrow before work and install it .

The cause, in my opinion: rust in the bearing plus a lack of lubricant (probably homeopathic amounts were used again during the production of this premium product).

Best regards, Rainer.

That gives me courage.

When I bought mine, I also had the material from the same company installed. At the friendly dealership, they strongly advised against it. Then, after 10,000 km, I had everything replaced again - for millions -. I'm generally very skeptical of original spare parts because I've only had bad experiences with them.

This is yet another proof...


Best regards, Manuel.

Unfortunately, I've had similar experiences:

I had the timing belt replaced 25,000 km ago, and it's now showing signs of deterioration. I might take a picture this weekend and post it here, but it has 'pimples' on it. The belt is from GATES, and it will definitely be my last one from them. I simply don't want to have to replace the belt every year just to save a few euros. Conti apparently isn't an alternative either, so only original parts from now on, at least for all the 'critical' components. If the engine fails because of a cheap solution, I won't be happy anytime soon...

Regards,
Master craftsman.

Which suppliers does the VAG group ("the friendly ones") use for timing belt kits?
Bosch? Or maybe ContiTech?

"In the Technical News of December 7, 2002, from ContiTech:"

"Timing belts for the 1.9L TDI engine are supplied to VW and Audi for original equipment... The CT timing belts for the automotive aftermarket have the same properties, in accordance with our philosophy (original equipment quality = replacement quality)."

@Rainer:

If it offers any comfort:
Here's what a tensioner roller for a G IV 1.4 gasoline engine might look like after 50,650 kilometers:

Man, this is all such junk .