2.0 TDI DSG Starting issue

[Samj06]

Hi Guys, bit of an odd one!

Had my mark v for a bit over six months and never an issue, a few weeks ago when I started her up it was really rough for about 1 second like some one was jumping (very fast!!!) in the bonnet and the bace to perfection and off I went, then on tuesday of their week I tried to start her and it just cranked for about 5 seconds and was doing the same 'jumping' thing again, at first i thought that it was due to the fact that I hadn't let the glow plugs warm up before cranking so I warmed them up and turned her over again, same thing, this happened about 5 times with about 5 or six seconds of cranking per time, then when i was about to call RACV to come look at it of she went perfect??? I have had a couple of weeks off work and have been doing some longer trips no freeways etc, and the fuel was about/bit under 1/4 tank?

Drove to a friends about 1hr away and parked in the drive way and when I went to leave a few hours later there was a puddle (very small) under the seam between the drivers and rear doors on the drivers side, had a sniff and it smelt like diesel, but that may have been my imagination?? The feeling that i got was that the fuel had leaked out of the engine back into the tank or onto the road?

Anyway had it looked at at volksaffair (really friendly and only to happy to squeeze me in(gotta plug decent service when you get it!)) they kept her over night and no issues could be found, no leaks etc, seems ok at the moment,but a bit worried that there maybe an issue with it I do have a five year warranty that I got with the car so not so worried about the costs associated with repairs but i am worried that the cranking may damage the engine as its such a harsh sensation?

any ideas?

Thanks in advance
Sam

[neromonk]

Not sure if the original poster has resolved their starting issue, but I will add my experience into this thread rather than start a new one.

I have a 2007 Passat wagon with 103kW 2.0 TDI engine.
Normally the engine starts instantly on the first push of the key and runs well.
Over the last few months, there have been about 5 or 6 occasions when it was reluctant to start. On these occasions, I tried several short bursts of a few seconds each on the starter, waited a few seconds, tried again etc. The engine eventually chugged into life, usually after a longer period of cranking of about 10 seconds or more which seems like an eternity when every other time it fires up in 1 second.
For the first few seconds of running after a difficult start, the engine ran poorly, stumbling and rumbling a bit and then smoothed out and ran well.

It sounds to my amateur mechanical ear like a fuel problem and so I have been taking note of where I am buying my fuel. Last month I had filled up at the big new 7-Eleven station near where I live and had the problem once. So this month I deliberately filled up at BP which I had been using regularly in the past. The problem happened again two days ago, so it seems to be independent of fuel brand.

It doesn’t seem to be temperature related either as the most recent time it happened, the ambient temperature was a balmy 21 deg C and car had been stopped for 20 minutes after a 20 minute drive. The previous time the car had been stopped for about 2 hours after a 20 minute drive. So the engine is neither dead cold nor overheated. (Most of our drives are 20 to 50 minute duration with occasional long distance highway driving on a weekend or holidays, but we have been doing that for years.)

The battery is one year old and is the car’s second battery. It is the Varta 72AH, like the original, purchased from a local VW dealer. The starter cranks at a good rate and even seems to speed up, not slow down after extended cranking when the problem occurs.

So far the engine has always fired up eventually, but I am concerned that it could give a problem when my wife is driving it and she tends to panic in these situations.

We are a bit paranoid as we had the dreaded fuel injector problem back in April 2011 with major dramas stuck on a busy road and eventually getting the car towed to a dealer on a public holiday. All 4 fuel injectors plus harness were replaced by the dealer under extended warranty which will run out in 10 months time.

Is it the fuel injectors again? Hope not. Why does it only do this about once a month or once for each tank or two of fuel? In fact it seems to be slightly more regular recently and so I am going to keep a log of date, fuel brand and level, driving conditions, ambient temperature etc to see if there are any common factors.

I have checked for engine fault codes with a VCDS and there are no engine faults showing, at least not by the time I get back home. I fear that taking the car to a mechanic or dealer when the fault is not occurring may be a bit of a waste of time.

Any help will be appreciated.

Details of the vehicle:

Model: Passat wagon B6, MY2007
Engine: 103kW 2.0 TDI BKP
Transmission: DSG 6-speed
Odometer: 80,000 km
Servicing: Regular 15,000 km intervals at dealer except for the last oil change service which was done by a local workshop, using VW 507.01 spec oil which I supplied.

[jazd]

My friend has a very similar situation with her Golf. My Golf was exhibiting similar behavior and was fixed by a new battery. Like you though her Golf has a new battery so I dont think thats the problem.

There are a couple of VW TPIs relating to rough starting of the 103kW engine, one is related to fuel pump/line issues and the other is supposedly fixed by upgrading the software on the ECU.

[vk]

My friend has a very similar situation with her Golf. My Golf was exhibiting similar behavior and was fixed by a new battery. Like you though her Golf has a new battery so I dont think thats the problem.

There are a couple of VW TPIs relating to rough starting of the 103kW engine, one is related to fuel pump/line issues and the other is supposedly fixed by upgrading the software on the ECU.

Thought I'd quickly add to this but I had a progressively worse start-up issue in my GT TDI, VW replaced the Cam Shaft Sensor and all returned to normal.