Engine Issue

Hi all

I hope somebody can help give me some pointers

Firstly my car is a 2007 Jetta 1.9 TDI PD SE 99,300 miles

The issue I'm getting is very difficult to really know what is happening.
About 12 months ago the car went into limp mode and my garage replaced a boost sensor under the warranty plan I had and all was ok.

However recently I am getting a kind of misfire or stutter while under normal driving conditions but it is very intermittent. Maybe one or twice per day (cover about 45 miles per day mainly on the motorway.) it seems to occur around the 1,500-2,000RPM range and gets more frequent when in stop start traffic.

The car feels as though there is a total loss of power for less than a second and then back to normal but it's enough to jerk the car slightly, passengers can also feel it.

There is otherwise no loss of power and the car can easily get over 80mph if needed. Doesn't seem to be excessive black smoke, I get some occasionally if I red line off the lights.

My first first thoughts were diesel supply so I've ruled out the fuel filter as it is clean. I'm thinking maybe injector loom but I wonder if it would be more regular if the injectors weren't firing. I'm possibly thinking the turbo veins are sticking breifly but I feel the car would go into limp mode of this are the case. Read somewhere about MAF but the car revs freely all the to 5,100 not an issues.
Maybe some form or vacuum fault but vacuum system seems ok except for an oil leak from the tandem pump to head but I can't see that it would cause this. But I could be wrong.

Tech at work has VAGCOM and he cannot find the fault. I did have a used car warranty plan on the car and was in for investigation a few times but nobody could fault the car.

I know the flywheel is beginning to knock slightly on idle but this wouldn't case the issue with the engine. I do have a spare injector loom ordered from TPS but not sure if it will cure so releuctant to fit at the moment.

Has anybody got any ideas of what it could be or know what the diag charges are from VW if I got a proper VW garage to check it (I work in a Mercedes dealer)

All help appreciated many Thanks

Matt

If it was a USA PD I would say ZipTie mode you may want to try that to see if it helps. Flywheel knock again if USA car then you need a new flywheel soon before if fails and causes a lot of damage

Have you inspected the injector loom in the cylinder head? The insulation is common to break down

Fitted a new injector loom today and while I was at it fitted a new tandem pump gasket. Didn't seat the tandem pump correctly into the camshaft. When I crank the car the pump snapped clean off of the head from the force. Fmfl

Update. Car has ran fine for the last 500 or so miles but is now the doing the exact same thing again. I can almost pinpoint it down to around 2,100 RMP is where the blip happens.

Does this car have an EGR valve like the BRMs do?
The electrically actuated version?
Try unplugging it and see if that does the trick. It will give you a CEL but should not affect it adversely otherwise. Make sure that the valve is fully shut first.

I believe the EGR is vacuum controlled as it has an actuator locates next to the EGR cooler. Is there anyway to test this type of EGR. The engine code is BXE if that helps it’s the PD105.

Little update to this. I ordered and fitted a new vacuum solenoid block from VW. £205 later still faulty.

I have vacuum tested the turbo actuator and it runs very smoothly in both directions.

I have pretty much ruled out injectors as the fault or fuel filter as I do not get the fault at idle or when using the cruise control.

I have checked all the vacuum lines and there aren’t any splits or cracks.

I had an issue yesterday with no boost at all but car would still rev to the limiter so I don’t know if this is different to limp mode

JETaah said:

Does this car have an EGR valve like the BRMs do?
The electrically actuated version?
Try unplugging it and see if that does the trick. It will give you a CEL but should not affect it adversely otherwise. Make sure that the valve is fully shut first.

Click to expand...

The car definitely has a vacuum EGR which I have blanked off on top of the cooler and pulled the vacuum line off from the valve. I plugged the hose and the top of the EGR. Seems like my fault has gone away which is good but now the idle seems lumpy. Is this normal? And I assume it will disappear once I replace the valve. (£36 brand new on eBay with a 12 month warranty)

I would expect EGR blocking to improve any idle issues unless the BXE's ECU does something a USA version does not. And I would also expect that you would get perhaps a different fault code because it is blocked off. Maybe that is yet to come.
Don't know the car, sorry.

Have your VCDS tech log the MAF sensor/EGR reading (group 003) and torsion value (group 004) at idle.