Diesel in Engine Oil? (Solved)

Hello,

"Shortly after purchasing my Passat (BMP engine), manufactured in 2008, I noticed that there was too much engine oil in it. The car had just been serviced at a VW dealership (by the previous owner, who lived 300 km away). To be on the safe side, I had the entire oil changed again, as my local dealer couldn't provide an explanation for this."
Since then, I've driven another approximately 2500 km, and today, during a check, I found too much oil again – it's estimated to be about half a liter.
I'm planning to go to the workshop next week; the mechanic mentioned on the phone that it might be a leak in the high-pressure pump (tandem pump)...

What's coming my way? / What am I getting myself into?

There are no error codes stored, and it runs normally, but the fuel consumption is a bit high. There's no oil visible in the coolant, and there's no water on the oil filler cap .

If the pump is clogged, it will also lack power!

If the car has always been serviced there, I would consider going back to that place.
Let's hear from the people at Volkswagen!

You bought a VW and not a Lada, so things should normally work!

In Austria, things like that are often resolved through goodwill and understanding!

More than being taken away in handcuffs, nothing else can happen to you .
Sure, here is the translation of the text from German to English:

"Best regards."

Hello,

The engine (replacement engine with 104,000 km on the clock) has only 45,000 km and was installed in April 2010. Surely there should still be a warranty from VW on it, right? Does the pump come with the replacement engine, or is it considered an accessory?
Is it a problem with Volkswagen if you don't go back to the workshop that performed the replacement?

Regards,
Dad.

Hello,

I can't find BMP in the list right now, but it seems to be a common rail system.

The oil seal of the high-pressure pump is located on the return side, meaning that there is a slight back pressure on the fuel side, which can push diesel into the engine oil if the seal is not in good condition. Bosch sells this seal individually, and I could find the part number for you if it's a high-pressure pump with a 20mm drive shaft. It's relatively easy to replace.


Furthermore: check, or have checked, whether everything is okay with the DPF. If it regenerates too often, or at a coolant temperature that is too low, this can also lead to excessive fuel entering the engine oil .

The BMP is a PD (presumably referring to a type of engine or device) with an output of 103 kW and 8 valves.

Quote:

The BMP is a power drive with 103 kW and 8 V.

Ohhh... so that explains why the mechanic wants to install a new high-pressure pump for him.

Quote:

The expert mentioned over the phone that it might be a leaking high-pressure pump...

Regarding the PD (positive displacement unit), I would suspect issues with the sealing of the PDE. Possibly, the PDE was installed without sufficient lubrication, which could have damaged the sealing ring and caused it to leak oil.

I would probably just replace it preemptively. A set of seals like that costs about €25 from VW, plus another €4 for the tensioner bolts, so it's all around €100. It's cheaper than spending 2 hours unsuccessfully troubleshooting the problem at the dealership.

You only need to be careful when removing the valve cover, as they are often difficult to access from under the intake manifold. Grinding away (Russian: "otfilit") the relevant material can help, or you can loosen the screws of the intake manifold at the cylinder head.


Dress code (no guarantee):

Tipping lever shaft: 20 Nm + 90°.
Camshaft bolt: 12 Nm + 270° (10 Nm + 180° is definitely sufficient and gentler on the threads).
Lock nut on adjustment screw: 30 Nm.
Adjustment: Rotate until it reaches the maximum extension, then rotate back 180°.

If a BRD (presumably referring to a building-related device) is shaking or vibrating, the first thing I would check is the ZK (likely referring to a specific component) for cracks.
Has a compression test or a carbon monoxide (CO) test been performed yet?

Secondly, the PD cable harness is suspected to be faulty.
The behavior should then always occur at the same engine speed, regardless of which gear is engaged.

Hello,

There was absolutely no talk of any stuttering or interruptions.
So, it's definitely a PD engine, which the mechanic certainly knows as well. However, on the invoice for the replacement engine, there is also a "pump" listed at a price of €272, and this appears to be a vacuum pump. Could that be what he was referring to?
The references to the PD elements sound logical, but aren't these already included and checked in a replacement engine at a price of €4425?

I'm sorry, that was the wrong post.
I have no idea how I came up with the idea to write this here .

p.s. Regarding the issue:
Was the DPF also replaced along with the engine?
Are you experiencing problems with pre-ignition?

It's possible that the diesel fuel entering the engine oil is coming from continuous afterburning attempts with post-injection.

Hello,

There's something to that - the soot content is currently at 59 grams, and of course, the DPF has not been replaced .
Today, I received confirmation from the that the problem will definitely be covered by the warranty through an engine replacement. I now have an appointment for next Thursday. They want to first check if there are any leaks in the PD elements, and then possibly replace this "high-pressure pump," which, according to the mechanic, was not part of the replacement engine but was replaced along with it.

Let's see what they can do...

Of course, I'm dealing with the DPF problem on my own again. When the Passat comes back from the workshop, I'll try a cleaning attempt, although the thought of removing the filter canister is a bit daunting . With the BMP, there's quite a bit of piping attached - I probably won't be able to do it without a lift. My small pit in the garage will definitely be too narrow.

Is your engine oil level consistently increasing, or does it remain at the same level?

I've experienced something similar before where the engine oil level was once slightly above the maximum mark, but it stayed there.

If a seal were damaged, the amount of engine oil would presumably increase with increasing mileage.

VW also stipulates that when replacing an engine, the tandem pump should be checked for internal leakage. That would certainly be a worthwhile measure.

Hello,

Well, I at least get the impression that there are more and more of them...
Where is this tandem pump located? And am I correct in assuming that it generates both pressure before the injectors and also creates a vacuum?

Baba wrote:

Where exactly is this tandem pump located...?

If you're standing in front of the engine, it's attached to the right side of the cylinder head.

Baba wrote:

and, am I correct in assuming that this device generates both positive pressure before the PDE, as well as negative pressure?

Yes, that's how it works.

Hello,

Okay, on Friday the Passat came out of the workshop - the tandem pump was replaced under warranty, and the oil and filters were changed .
Well, as soon as I got home, I checked the oil level - and sure enough, there was too much again . I immediately called the master mechanic, who said that the technician might have filled it a bit too much, and that I should just keep an eye on it... could that still be true ???
Surprisingly, it wasn't even checked for leaks in the pressure differential equipment (PDE), but the pump was immediately replaced .

Now, however, I have the feeling that the Passat is consuming less fuel – at least, that's what the onboard computer says.

The problem seems to be solved now.

The mechanic at the workshop had actually overfilled the oil. After I drained about half a liter, the level was correct, and it hasn't risen since.
So, it was definitely a problem with the pump .

Thank you again for all the tips!

Regards,
Roland.

Thank you for the feedback!