"Missing" on cold start

[PhilMart]

Hi guys

Have an 08 GTI 6 Speed Manual.

For about the last three months my car when cold has, for want of a better word, been missing when accelerating. You can feel it accelerate a bit then acceleration is retarded for a bit then accelerates again. This produces a jumpy feeling and you can almost hear little burps from the exhausts. Once the engine warms up all is OK. Idling seems OK when cold or warm.

There are apparently no fault codes and VW dealer replaced the PCV thinking that might be the cause but I am still getting the problem.

I read on another post about coil packs, but that would bring up a fault code and seems to occur when the engine is hot rather than cold?

Any ideas?

[Deadpool]

This is the exact same thing that happened with my DSG. I did a VAGCOM scan and I couldn't find any issue. When I took it to VW they plugged it into their VAS and it came up with a Coilpack Error but didn't say which one. I ended up just buying a full set of R8 Coilpacks for $50 and it got sorted. The issue ended up being with Coilpack #3 though.

[Jmac]

More than likely carbon build up around the injectors and intake. Only real fix is to strip it down and have it cleaned. If it were a coil pack it would get worse as it heat up and yours is ok warm. Common this now I'm afraid
Cheers
Jmac

[Paul_OH]

I had a similar issue on my TSI, it was initially thought to be coilpacks then turned out be injector failure. Injectors were fine on anything but cold start but after replacing them the issue was solved. Coilpack replacement improved it but didn't solve it.

Not saying that it is the problem but worth checking regardless

[Jmac]

As I mentioned above its the carbon that kills them, new injectors is a band aid . Yes it'll fix it for a while.

[Fixxxer]

Is this still on its first battery? If it is, replace it (or get a load test to prove its good or not).
If this isn't the case, listen to Jimmy, he's smart.

Fixxxer

[PhilMart]

Thanks for replies.

Is on its second battery so no problems there .. probably only have less than a year on the new battery.

Anyone got an idea of how much fixing it would be if it is carbon build up?

If it helps with diagnosis .. just on 105,000kms

Thanks

Regards

Phil

[JimR]

"Missing" on cold start

Just had mine cleaned, $990 all up. However I also had a leaking injector replaced just this week but now she's right

[PhilMart]

Just an update.

Went to dealer and told them about it and it would seem without testing anything decided that the PCV valve needed replacing. No change! So then they decided that they would need the car overnight to look at it further.

Losing a little faith in my "Car Shaman" I decided to immerse myself for a few hours in the joy of the internet. After searching from one end o fthe internet to the other I found that this problem is quite common and that there were a few other forums talking about what VW had to say about the issue when it arose. Apparently the cause of carbon build up is due to low revs in part, and that they suggested (I believe in USA) that you simply run the car under load for 20 minutes at over 3000rpm.

So off to the highway I drove. Got to 90km/h in 3rd and it was RPMing at 4000 odd. I figured if 3000RPM was good then 4000RPM must be better! I also did it for 30 minutes.

Next morning I found a DEFINITE improvement, almost to the point the original problem was not noticable. I really need to accelerate and pay attention to feel / hear a slight misfire under load when cold.

So am I happy or what! Saved a couple of hundies in the deal. I figure I will do it again soon and then perhaps as part of every 1000km to try and keep things under control.

Thanks for all the comments and assistance.

Not sure if I can put the link in .. as it is another VW forum where I found it.

[Fizz]

Just an update.

Went to dealer and told them about it and it would seem without testing anything decided that the PCV valve needed replacing. No change! So then they decided that they would need the car overnight to look at it further.

Losing a little faith in my "Car Shaman" I decided to immerse myself for a few hours in the joy of the internet. After searching from one end o fthe internet to the other I found that this problem is quite common and that there were a few other forums talking about what VW had to say about the issue when it arose. Apparently the cause of carbon build up is due to low revs in part, and that they suggested (I believe in USA) that you simply run the car under load for 20 minutes at over 3000rpm.

So off to the highway I drove. Got to 90km/h in 3rd and it was RPMing at 4000 odd. I figured if 3000RPM was good then 4000RPM must be better! I also did it for 30 minutes.

Next morning I found a DEFINITE improvement, almost to the point the original problem was not noticable. I really need to accelerate and pay attention to feel / hear a slight misfire under load when cold.

So am I happy or what! Saved a couple of hundies in the deal. I figure I will do it again soon and then perhaps as part of every 1000km to try and keep things under control.

Thanks for all the comments and assistance.

Not sure if I can put the link in .. as it is another VW forum where I found it.

good find, run some seafoam through the system then do the above should help with breaking down the sludge a little better. Nothing will be as good as taking it apart to clean but I have noticed seafoam made a noticeable difference to my car.

[Jmac]

good find, run some seafoam through the system then do the above should help with breaking down the sludge a little better. Nothing will be as good as taking it apart to clean but I have noticed seafoam made a noticeable difference to my car.

Only real way is to strip it down im afraid. I know , its a total pain, but a fact. Done that many now. Well used to haha.
Good luck
Jmac

[lol.u.mad.bro]

same issue with my car. changed coil packs, spark plugs, leads... everything! still studders on start up and idle