Misfire - 2010 Passat B6 2.0TDI CR CBDC Saloon

[russell2019]

Hi All,

New to the forum, apologies if i've posted this in the wrong place.

I've just picked up a 2010 Passat R-line, with 190k miles on the clock. The car had runaway so i got it cheap, drove it home being extra careful and ready to stall it if the runaway happened. Smoke cleared after a few miles, but i noticed a really bad misfire.

So, here's what i know:

• Engine is smooth for first couple of minutes, gets worse the hotter it gets

• VCDS showing P0300 & P0301 (although P0301 hasn't come back after 15 miles since being cleared but P0300 has returned)
• Compression in cylinder 1,2,3 showing 400-410psi, cylinder 4 has a snapped plug so can't check that yet .
• Injector leak off test didn't seem to show anything major at fault, all 4 seem to be returning similar amounts of fuel, but i did it in a rush and couldn't measure exact figures.
• Flywheel is making an awful chattering noise, which goes with the clutch pressed down (could it be that bad it's causing misfire?)
• Fuel filter is clean, no metal
• At idle, the fuel consumption on VCDS is 0.21 liters an hour, and on the 50 mile drive from Rochdale to Chorley, the car returned a whopping 78mpg. My daily driver (another CBDC engine) has an idle of 0.6 liters per hour, so a big difference there.
• Rpm at idle is bouncing up and down between 750rpm & 820rpm, on my daily driver, it's steady at 805rpm on vcds.
• Injector values on vcds also fluctuate quite a lot, but never exceed the +2 & -2 specified, but again on my daily driver which was rebuilt 6 months ago, they are quite steady closer to the 0 mark.

I wanted to see if anyone had experienced anyhing similar, or could suggest what the next steps would be? I think i'm going to pull my injectors from my daily, and test them in this to see if that help, and also the fuel qty valve on the HPFP.

Below is a link to a video of the misfire when it is hot.

Bad misfire 2010 Passat B6 CBDC 110 2.0TDI - YouTube

Any help is much appreciated, i'm hoping this will be a relatively easy fix, as I'd like this to be my new daily driver, it's much more of a looker than my current one.

Cheers.

[Crasher]

The +/-2 spec is way to much, anything over 0.5 makes me suspicious but I had this on a Golf 6 CBAB last week and she had put petrol in it. Your problems point to number 1 injector being faulty, it is a very very common failure and can make the MF hammer away.

[russell2019]

Thanks Crasher,

I was hoping you'd see this post - it may be my first 'proper' post, but after viewing this forum countless times over the years your replies always seem to be knowledgeable and most helpful, certainly helped me fix a number of faults.

I have a load of spare injector seals, so tonight i'm going to pull number 1 from my daily, and pop it in to see if any change, will update in due course!

Cheers - Evan

[DMitch16]

Thanks Crasher,

I was hoping you'd see this post - it may be my first 'proper' post, but after viewing this forum countless times over the years your replies always seem to be knowledgeable and most helpful, certainly helped me fix a number of faults.

I have a load of spare injector seals, so tonight i'm going to pull number 1 from my daily, and pop it in to see if any change, will update in due course!

Cheers - Evan

Common Rail injectors usually have an IMA and will need coding if your daily does not have exactly the same part number.

[Crasher]

Common Rail injectors usually have an IMA and will need coding if your daily does not have exactly the same part number.

good point

[russell2019]

Common Rail injectors usually have an IMA and will need coding if your daily does not have exactly the same part number.

thanks, I swapped the number 1 injectors round from both cars last night and coded them as required, but unfortunately no change.

It may be worth noting, that I have pulled the dpf as I thought the misfire was maybe due to too much back pressure from a clogged dpf/cat ( the car had blown a turbo, and a new one put on but I don’t think they cleaned the intercooler/piping hence the runaway) but even with the dpf disconnected there is thick clouds of white smoke (mayb blue but can’t tell under the led light)

unfortunately the injector swap made no difference, I actually drove to work this morning with number 1 injector from the bad engine in my daily driver and it was fine.

im not fully convinced however that one or two of the injectors aren’t faulty, going off the fluctuating vcds figures.

im hoping to properly clean out the intercooler and piping tomorrow, and try my injectors in it, and see what happens then.

unless anyone has any other ideas what it could be?

thanks once again

[Crasher]

Are you sure it does not have some petrol in it?

[russell2019]

Hi Crasher,

Not sure, sorry, but it has 3/4 of a tank left - just how i picked it up last week.

Any quick tests i can do to check, or is it a case of draining the full tank and filling with fresh diesel?

I must say, having looked at the fuel filter, it certainly looked as if the fuel was more brown/yellow, rather than the greeny blue im used to seeing in tdi fuel filters. Hadn't even clicked but that could well be the case.

I'll snap some shots tonight and compare the colours of fuel from my car to this car

[Crasher]

An olfactory sampling of the filter contents should provide a clue, if in doubt, bilge, flush and refill with fuel of the Devil.

[DMitch16]

Are you sure it does not have some petrol in it?

Or a loose exhaust manifold / naff gasket as that can cause a great deal of smoke?