Persistent Whistle & Exhaust Fumes in Cabin: VW Caddy Skap 2008; 2.0Tdi; 140HP; BMM Engine

Hi everyone.
I have a VW Caddy Skap 2008; 2.0Tdi; 140HP; Engine Code BMM. Mileage - 450,000 km.
Oil, filters - changed regularly every 10,000 km. Timing, water pump, etc. every 80-90 thousand.
Let me start at the beginning, it is possible that some information may be useful.

At the mileage of 380,000 there was a whistle / whistle from under the hood and the smell of exhaust gases in the cabin. Quiet at first, gradually louder. Always when accelerating at around 1800 revolutions. After taking your foot off the gas or exceeding 2500 revolutions, calm down - no strange sounds. At 400,000, I gave the car to the service for sure. They changed the guts in the turbine, checked the injectors, tightness of the system, etc. After driving 1500 km, the entertainment was repeated - the faults resurrected.
Unfortunately, I couldn't find the cause.

With 449,000 mileage, I was forced to remove the head and send it to a service station in Poland. Too many divergent theories about the fault. The head has undergone full service. Camshaft, bearings, glasses, etc. After folding, I drove 300 km and a miracle happened - the whistles / whistles resurrected again but without the smell of exhaust fumes in the cabin. After 600km there was an oil leak on the back of the engine. I washed the engine, took off and put the valve cover back on - I used to do this. I drove 8 km and I don't believe - silence in the car, no whistle / whistle. I don't think it is possible. In the morning on the way to work, all the whistles / whistles returned. The engine shows that the head and collectors are dry and clean. The engine block and everything around it is covered with oil. Could it be a badly installed head gasket?

Some useful information:
- During the assembly of the head, the gasket was not damaged or broken. The head is tightened with a torque wrench according to the scheme with the intervals between the stages of tightening with new bolts.
- After assembling and starting, the engine worked and continues to run without any problems. 0 errors.
- A set of gaskets ordered from the service where the heads were repaired (from the top shelf)
- All accessories carefully washed and free of carbon deposits.
- Replaced EGR exhaust gas cooler after regeneration. EGR valve cleaned (it's already the 3rd time)
- Camshaft position, exhaust pressure and oil pressure sensor replaced with new ones.
- The coolant does not mix with the oil. Oil with liquid as well.
- We did not part with Autocom during the repair and commissioning.

It seems to me that I have presented everything that is essential. I will just add that I live abroad, I do most of the repairs myself or with a proven Swedish mechanic where, unfortunately, the costs are high, even very high. Diagnostics anywhere on the site also costs a fortune. I also have a fondness for this car - hence the decision to repair a 10-year-old VW with a mileage of 450,000 and one of the most defective engines.

Whistles / whistles - Friends are betting that it is a leak at the inlet, I checked everything and it looks ok. The only thing left is the EGR valve damaged. Is it possible ? Perhaps someone has had such a problem and knows the solution, or will give you a hint before incurring unnecessary costs.

Oil leak - I do not understand where the oil comes from ... "Lubrication" of the turbine - clean and dry everywhere. Turbine oil return - dry. Valve cover - rather falls off. Front of the engine - dry and clean. Everything points to the head gasket ... but the engine is ticking much better than before the repair. Tomorrow and in fact, today I will come to check the compression. And here my ideas end. In order to locate the leak, I would have to disassemble everything again and be without a car, which I cannot afford at the moment.

I hope that there will be someone who has a similar problem and I will be able to reward him for help with a solid brewery.
Best Redgards. Patrick

Buddy, have you checked the alternator belt, alternator bearing and tensioner?

Hi, I did not use it myself, but one colleague here on the forum for difficult to fix oil leaks recommends washing the engine and sprinkling it with flour - it's probably worth trying, no gasket on some sensor?
The whistle can be from the places where the exhaust system connects - EGR, gaskets, intercooler (intake), cracked flange or turbine housing - check connections, manifold.
I do not know what the exit from the air filter looks like, but if the branching to the valve cover (oil line - vent) check the connection - or test wrap with 3m tape - PSA often has a whistle for this reason.

daro31ie wrote:

Buddy, have you checked the alternator belt, alternator bearing and tensioner?

Yes. New belt, alternator and tensioner bearing in very good condition.

kakibara wrote:

no gasket on some sensor?

If there was a gasket in any of the sensors - it was replaced with a new one.

kakibara wrote:

recommends washing the engine and sprinkling it with flour

Good advice always included. And some patent for leakage of the intake, exhaust, EGR?

kakibara wrote:

The whistle can be from the places where the exhaust system connects - EGR, gaskets, intercooler (intake), cracked flange or turbine housing - check connections, manifold.

While disassembling, visually I did not observe any cracks, deformations, melting, etc. When I put it together I had no difficulties with fitting and twisting the accessories, it rather went like Lego blocks. Screws tightened sensitively or with a torque wrench (if we knew the value). As for the seals, I ordered the service where they made the heads. The gasket between the throttle and EGR was missing (we matched a different one) and the gaskets of the exhaust gas outlet from the EGR cooler to the manifold (old ones). I dismantled most of the equipment and cleaned it thoroughly. Of course, very carefully with the turbine and electronics.

kakibara wrote:

if there is a branch to the valve cover (oil line - vent), check the connection

It is probably about this element


It looks ok, it buckles up slightly. I'll put tape on it just in case.

We put the engine together in two, carefully and precisely. We tried to check whether everything was in place and well twisted. I would bet it was the fault of some valve or sensor, because before removing the head, the symptoms were almost identical.
I will try to take some photos from the bottom, maybe they will help.

There, the axle often whistled on the exhaust gas cooler at the rear of the engine.

T5 wrote:

There, the axle often whistled on the exhaust gas cooler at the rear of the engine.

More than one person has told me that. The old one was terribly damaged and "rickety" so I exchanged it for one after regeneration. The seller assured me that it is regenerated (not just washed), and so are the membranes. She looked ok.
It is possible that the seller deceived me.

I checked the intake again, connections, o-rings. There is no indication that there is any "fel" here. I looked in the turbine, the impeller has too much clearance in my eyes. It is known that it cannot be tightly folded, it must have some slack. Well, in my opinion, badly worn blades ... It is possible that a badly assembled / balanced turbine gave a whistling effect?



As for the oil leak.
After driving 1000-1200km, about 100ml was lost.
I took off everything I could to see the manifolds, heads and engine block. I took a few pics:



Then I washed everything thoroughly, folded it, rode back and forth under the car. Unfortunately, I was caught at night and without re-disassembling some parts, it is difficult to accurately determine the place of the leak. In one of the photos, I marked the area where fresh traces of oil appeared. Starting from the collector (unfortunately mostly covered) to the half of the block. I had no way to take pictures.

In the meantime, my friend took the car to listen and possibly suggest something. He checked cylinder compression - book.
After 2 days, he called that there was no leakage ?? Wtf. I did 350km and maybe a minimal drop appeared twice. Block slightly dirty, but not as tidy as before. And I ask witchcraft?

Often the gasket leaks under the vacuum pump, then the oil is poured onto the back of the engine.

Right. Why hadn't it occurred to me before. After the first assembly, there was a slight diesel leak from under the pump. We changed the gasket a second time and peace of mind. If I get a new one immediately, I will do it and let me know the effects.

The leak has been eliminated.
As a colleague T5 wrote - The leak was mainly from the Vacum Pumps, but also gently from the valve covers just above the pump. The seal was a bit lower than the factory seal.
This time I bought original gaskets in a VW showroom and it has been dry for 1.5 weeks.

The question of the whistle remains. I have heard that it may be the fault of a clogged DPF? I don't know what to think, it seems to me that a clogged DPF = no power and a silted car. Rather, it won't get it normally. I replaced the exhaust flexible connector after the DPF because it was in poor condition.

Still, it seems to me that the whistle is coming from somewhere. I will let people know how to locate the fault.