Crankshaft Phase & Injection Timing Explained

Hello everyone!

Here's the background: About 10 days ago, I started my car in the evening, and suddenly there was a strong smell of burnt oil inside the car, and the engine was making a much louder noise. Then, almost all the lights on my dashboard turned on, and the power steering also stopped working. I had just driven the car to the side of the road and turned off the engine, and then the ADAC (German roadside assistance) had to tow it to a workshop.

Diagnosis: The vibration damper was broken, the V-ribbed belt was starting to disintegrate, and the timing belt was already cracked!!

"The workshop has now replaced the timing belt, but when I got the car back, it was making a noise like a 70s diesel engine in -20 degree weather! The workshop's explanation: it's likely a consequential damage resulting from the broken shock absorber."

After a sleepless night, the next morning I checked the injection timing with the Lappi device: the injection timing was so early that it couldn't even be displayed. I then went to the workshop and asked them to readjust the injection start.

In the afternoon, I picked up the car, and the noise level hadn't changed significantly. The mechanic said that it's no longer possible to properly adjust the injection timing because the crankshaft has significantly more play than it should. He added that a complete overhaul wouldn't be worthwhile.

The explanation seems illogical to me, although I am just a layman. Apparently, the valve timing was initially set statically using a timing tool for the camshaft and by rotating the crankshaft to the top dead center (TDC) position, and then adjusted dynamically by twisting the electronic spark advance (ESA).

Can someone either confirm this explanation or tell me it's nonsense? I'm thinking about having the timing adjusted at a Bosch service center next week. If they can actually fix it, the first mechanic to do it gets the bill. If the Bosch service center confirms this statement, I'll have other problems anyway.

Regards,
a desperate Thomas.

EDIT: Does anyone know a GOOD mechanic in the Solingen, Wuppertal, or Remscheid area for my car?

Hello Klopfer.
Your statements perfectly match the experience of a friend of mine who took his car to the workshop after noticing a water pump failure (early enough). The water pump and belts were replaced.
After a certain amount of time, it experiences extreme starting difficulties and hard diesel knocking.
During the check with the Bosch KTS diagnostic tool, the ESP was activating too early, and the engine control unit was unable to compensate for the adjustment. (This was the first time the car was in a workshop after 260,000 km; we had performed all previous maintenance ourselves.)
The dealer told us that the problem could also be coming from the cylinder head, and that their own tests showed the readings were within the normal range, etc.
After repeated insistence on ensuring that everything was properly adjusted and that the KW screw hadn't loosened, they agreed to keep the car and re-check their work. We had previously made it clear that disassembly of the ZK (likely referring to a specific component) was not an option, and that otherwise, we would take the car back and personally inspect the belt drive and pump settings.
The next day, the car started perfectly again, and the knocking sound was gone.
We talked to the - really nice - mechanic, and according to him, the pump was right at the tolerance limit of its setting.
We didn't comment further on it and made our own jokes about it.

Conclusion: This is a super reliable car, but it needed to go to the workshop for the first time, and after that, things weren't right. The workshop wanted to remove the cylinder head and replace the hydraulic lifters, which would have also meant replacing the belt and then re-aligning the pump.
Of course, this expensive extra repair would also have led to the "success."

Okay, I would insist that the pump settings and the motor control are checked, or even better, if you have the ability, do it yourself. That way, you can at least be sure that everything is installed correctly.

That gives me hope that the mechanics at the workshop really messed something up. I also can't imagine that the KW (suspension) is broken, since the timing belt isn't torn. Unfortunately, I don't have the ability to adjust the static injection timing myself; with dynamic timing, it's not a problem thanks to VAG-COM (and this community)! I'll call the Bosch service tomorrow.

Report to follow!

Regards,
Thomas.

Hello there,

I had announced that I would provide an update: so, I took the car to the nearest workshop to have the initial diagnosis checked. They were able to adjust the injection timing, but the engine still sounds very unhealthy. And the next diagnosis: the engine noises are not coming from the incorrect injection timing; it's likely that either a valve or a valve spring is broken. When I asked how certain they were about this diagnosis, they said 90%. The repair cost, if the cylinder head needs to be replaced, is 1,800 EUR. However, they can only be 100% certain after removing the cylinder head.

Right now, I'm considering whether to invest another nearly 2,000 EUR in this project or to get something new instead.

Sincerely,
Thomas.

Hello,

überprüfe doch erst einmal ob nicht nur ein Hydro hin ist, weil dazu muß der ZK nicht runter. Wisearch function.

Best regards,

Hi,
Even if it's perhaps unlikely:
Have you ever checked the vacuum pump for unusual noises?
Especially with our R5 engines, they tend to become quite noisy after a certain amount of mileage.
What happens to the sounds when you press the brake pedal forcefully several times in a row (5 to 8 times)?

Best regards from Berlin.
Olli.

Hi again,

After the second workshop adjusted the injection timing from early to late, exactly what I expected happened: it's now very difficult to start, which is a well-known phenomenon.

Since I currently lack the time and the in-depth technical expertise, I've taken the vehicle to a workshop. I've asked them to open the engine and perform a thorough diagnosis, including a cost estimate.

I will report back on it.

Regards,
Thomas.

Here's a short and, for me, beautiful concluding report:

It turns out it was just the injection timing that was misadjusted! What I told the first workshop, that they had only made markings on the gears, turned out to be true. The second workshop, which had already suspected a valve or valve spring problem, went through the entire adjustment procedure again. The engine was set to top dead center (TDC) by removing a glow plug, then an adjustment tool was used for the camshaft, and now the engine runs smoothly like a kitten. According to them, the loud engine noises were caused by the valve slightly touching the piston – a near-catastrophic situation, but it could have been worse.

"This company has now charged me another 300 EUR for the listing (which is a real slap in the face, considering the estimated costs are around 2,000 EUR). Now, I'm going to visit the first workshop, show them the engine that's running perfectly, and then offer them the 300 EUR to fix the mess they made. Let's see how they react."

Sincerely,
Thomas.

Hello Klopfer,
"Then you experienced exactly the same thing that happened to my acquaintance with his AEL. However, in his case, it wasn't as extreme, so the valve and piston didn't touch. I also can't quite believe that this really happened; the engine would have to be extremely misaligned for that to occur, and there's usually some kind of damage."

Anyway, it's quite a coincidence that our experience seems not to be an isolated incident, and that your second workshop also just randomly adjusted the pump instead of properly calibrating the engine control unit.



Best regards, Norbert.

...
The second workshop, which had already suspected a problem with the valve or valve spring, repeated the entire adjustment procedure. The engine was set to top dead center (TDC) by removing a glow plug, then an alignment tool was used to adjust the camshaft, and the engine now runs smoothly. The loud engine noises were apparently caused by the valve lightly contacting the piston – a near-catastrophic situation that could have been much worse.
...
Assigning KW to OT can also be done differently...

And if even the slightest contact between a valve and the piston has occurred, your problems are far from over.
Piston damage is just a matter of time.

Best regards, Georg.