Passat B6 2.0 TDI hot starting issue

**freebird69** · 22-07-2009,08:36 AM

I have a 2005 Passat B6 2.0 TDI that is difficult to start when the engine is at normal running temperature. It catches on first crank but when you release the starter, just cuts out ... if you hold the starter for several cranks, it will eventually start. When the engine is cold or has just been stopped in last few seconds, it starts ok. I'm guessing there's a temperature sensor somewhere that's mis-reading though not completely failed as there is no engine management malfunction indicator showing. The vehicle also seems to run ok when hot. Does anyone know the likely cause?

Also, can there be fault codes accessible to a vag-com but don't light the malfunction indicator?

**jonsey24** · 22-07-2009,11:41 AM

Ive had a similar issue with my car, although i had the fuel pump recall done by main dealer (Not related to this issue).
Since the repair it seems to have been ok although on occasions when the car is upto temperature and you have stopped then re start it can take 2 turns to fire up

**the surfer** · 22-07-2009,05:40 PM

I have the exact same problem.

Car starts first time, every time when cold, but needs 2 or 3 cranks to start when it's hot.

I've booked mine in today at the dealer so I'll report back as to what the outcome is.

**dch** · 26-07-2009,09:03 AM

Originally Posted by the surfer

I have the exact same problem.

Car starts first time, every time when cold, but needs 2 or 3 cranks to start when it's hot.

I've booked mine in today at the dealer so I'll report back as to what the outcome is.

What was the outcome?

I have a similar problem but only during the summer months. When I get back to the car on days when its been hot and sunny (rare I know), my donk runs really lumpy for about 1/2 a mile, then clears and is as per norm. My motoring experience (33 yrs) tells me that this is fuel related, but the engine starts first time everytime.
The car is black and obiously acts as a heat sink, but is it likely that the diesel is 'evaporating' in the injection system? and why doesnt it have this problem when starting with the engine hot?

**kuldad** · 31-07-2009,12:12 PM

I have 2006 passat estate with the 2.0TDI with DSG around 65000km.

I have exactly the same problem as dch. Problems with "uneven ride" when driving the first 3km when the engine is 20-50 degress (Centigrade) .

I have had it at the dealer a couple of times, they have "zeroed" the software for the DSG gearbox. This hasn't really helped. I have been to another dealer as well, they have made a complete fault diagnosis read out, with no issues. I'm really pleased with the Passat, but this is something I want to get to the bottom of, before the warranty goes out this october.

**freebird69** · 31-07-2009,08:33 PM

@the surfer: has the dealer found the cause of poor hot starting?

**Quatrelle** · 31-07-2009,09:44 PM

Originally Posted by kuldad

I'm really pleased with the Passat, but this is something I want to get to the bottom of, before the warranty goes out this october.

Keep a record of your visits to the dealer, so that if the problem comes to a head out of warranty you have a point to argue from.

**the surfer** · 01-08-2009,12:21 PM

My car goes in on Monday so I'll give details later on that evening.

**the surfer** · 04-08-2009,11:37 AM

For anyone who is interested: my car is in at VW and they've checked it over (scanned for faults I expect) and they can't find anything wrong.... They said if it gets worse to take it back in.

If there isn't a fault and it's a quirk of the car then I can live with it. However, if it's a fault then I want to get it sorted now. It seems a fairly common problem anyway.

Quite a few people have suggested replacing the crank temp sensor. Is this expensive??

**freebird69** · 20-08-2009,09:16 PM

I've only owned my current B6 for 4 weeks and have been using Shell V-Power diesel as I've heard good reports from a couple of taxi drivers who use it ... extra mpg, performance, etc. It may be a little premature to attribute to the fuel but hot starting has definitely improved since my original post. My intention was to use V-Power every 4th fill or so to keep the injectors clean but in the light of the starting improvements, I've decided to use it continuously for another couple of months. I'll update again in another few weeks and let you know if the improvement continues.