T5 AXD: Rattle in Airbox - Diagnosis & Fix

Hello.

I'm having a problem with my T5 AXD. I've been hearing a noise coming from the air filter box (a dull thumping sound that varies with engine speed). When I accelerate, the thumping gets louder.

It's difficult to describe, but maybe someone else knows about this problem.

I found a video about this; what do you think of it?

http://www.youtube.com/watch?v=C1jAfeRnmRk

The preheating light isn't flashing for me, and the error memory is also clear.

Thank you, Chris.

Is the intake valve not closing properly? Are there any other unusual symptoms, such as white or gray smoke?

What does the idle speed control say in measurement block 13?

Best regards, Rainer.

What does the error memory say?

I've experienced a similar knocking/rumbling sound coming from the air filter housing before. In my case, it was caused by worn camshaft lobes.

What does the error memory say?

I've already experienced a knocking/rumbling sound coming from the air filter box before. In my case, it was due to worn camshaft lobes.

Ditto .

chli1976 wrote:

I've already experienced a knocking/rumbling sound coming from the air filter box before. In my case, it was due to worn camshaft lobes.

I agree. There should also be a loss of power at lower RPMs. The one in the video has more problems; something is leaking somewhere, and a healthy engine would immediately stall if you close the fuel shut-off valve.

The error memory is clear, and you were right, it's the timing belt. There are noticeable grooves on the camshaft in two places.

Even during the idle speed control test, nothing unusual was observed.

"For some time now, I've also been having the problem that it takes a very long time to start the car in the mornings, but only when it has been turned off overnight."
What do you think might be the cause of this? Could it be related to the Northwest (NW) area, or are the PDE seals also damaged?

I just hope I can get the tools; it's crazy how much you need for everything.

Great gear construction, or what?
It might be a good time to replace the positive displacement (PD) seal rings now as well. However, that's quite a bit of work if you want to do it properly.

Sure, great design, a real masterpiece from the VW engineers.

It seems that it's not uncommon for the NW units to break down .

If it's difficult to start, be sure to replace the sealing rings of the PDE (positive displacement element).

Four out of the five glow plugs were also defective, but the engine control unit did not detect this. There were no error codes.

That should normally be stored in the error memory, right?

No, the AXD engine is actually the Euro 3 version without a DPF (Diesel Particulate Filter), EGR cooler, electric EGR valve, and all that stuff.
Glow plugs are only monitored from the Euro 4 standard onwards.

Hello, after replacing the water pump, hydraulic components, needle bearings, rocker arms, and all pressure plate seals, the car is running again.

Now I have a problem: there's diesel in the engine oil, and quite a lot of it.
After approximately 3000 km, I had almost 4 liters of diesel in the oil .

I've now also replaced the tandem pump. It was only producing 4 bar at 1500 RPM. With the new pump, I'm now getting between 8 and 9 bar at 1500 RPM.

However, unfortunately, after just 2 days, I already have about 0.5 to 0.75 liters of diesel in the oil again.

Could the sealing ring have been damaged during the installation of the power distribution element (PDE)? It's also possible that the control unit is still defective.

Is there a way to check if the seals are in good condition?

Thank you, Chris.

Diesel fuel in the oil can definitely be caused by damaged piston ring seals! You should not continue driving like this, as it will wash the oil out of the cylinder bores.

Hello!

I have now removed all four PD elements, and one of the sealing rings was slightly damaged.

What I've noticed is that on all four injector seats in the cylinder head, there are significant grooves, but only on the right side. These groove formations can also be seen on the injector elements themselves.

I don't have much experience with PD engines; are these noises normal?


Thank you, Chris.

Why were only 4 production facilities expanded?

oops, I misspoke; of course, all five.