Hesitation and lumpy idle??

[Phill]

Hi guys and gals

I've recently just bought a MK5 GTI on a 55 plate and since owning it, I've noticed its running lumpy and sometimes rather hesitant..  I did have a misfire on cyclinder 1 a week ago but they changed out the coil pack on cyclinder 1 and it seems to be ok, but its still got the lumpyness and hesitation...

Its more so at lower revs, upto 2000rpms or so, seems to be like a jack in the box at times!! :lol:  I just wondered if anyone knew what might be causing this problem, because its going into the VW Garage for an MOT on Thursday, but they'll have the car from Wednesday night to check it all over for me.  If have some ideas of what could be causing the car to feel like its holding back that would be ideal.  since the hassles I had with my GT TDI with them, they wanna keep me happy or else they'll have the keys back!!

I know I'm driving it rather light footed at the moment as when I mentioned I was getting over 38mpg the reaction I got was shocking!! :lol:

Any suggestions or thoughts would be great   Thanks in advance

[john_o]

Hi and welcome,

It seems common that if one coilpack has gone , its prob advisory to replace all 4.
Depends on the error message next time its plugged into vw diagnostics.

This is a good ref piece
http://www.golfmkv.com/forums/showthread.php?t=24952

Let us know how you get on

[Phill]

They did only replace the single coil pack as they'll only seem to replace the item thats faulty.  It was the same for my GT TDI when I had a tappet gone, they only replaced the single tappet that was faulty, not the complete set. 

It was complaining about the misfire on cyclinder 1 but also that the turbo wasnt getting the correct boost, but I'd assume it was due to the misfiring anyways?

I've got a few things on my 'list' for them to have a look at and I hope they have a good hard look as with the problems I've had with my TDI I hope they are more likely to sort these out rather than me going after another Golf elsewhere...

I will see how things go with the MOT they are doing and whatever else they find.  Hopefully it'll come back as it should be, but I have my reservetations about it.  When they test drove it, they said it seems fine, but its not fine for me!!

[john_o]

lumpy idle is normal (within reason)
incorrect boost I wouldnt normally link with a coil pack though.
Read that thread and see if a common element might cause both (e.g. something like fuel pump lobe wear issue)

[Phill]

I dont think lumpy idles should be normal on a £15k car!! :lol:  God it reminds me of all the hassles I had with my Scooby after I had that remapped... Ugh..
Well they where mentioning that the incorrect boost was due to the misfire as it was not fueling that cyclinder when it was misfiring so I assume it would do that anyways...

I dont understand why the car is lumpy or holding back whilst accelerating slowly tho?  Makes me feel like I'm in a jack in the box at times :lol:
I wish we had some decent rolling roads by us because that would definitely show if something was wrong with the boost, fueling or map for damn sure...   Might be nice to also have a base figure if I decide on mapping it or something...  Got to definitely change those front brakes anyways....

Thanks so far for the advice

Also a quick question....  The VW garage I bought it from, said to use Super Unleaded in the car rather than the normal 95 Ron stuff, is this a good thing to do or not?  I notice on the filler cap that it suggests to use 98 ron but where I live I dont have any Shell garages close to me..  Not unless I wanna go for a 90 mile around trip anyways :lol:

[Top Cat]

Tesco's does 99 ron 

[Phill]

I thought that was only 97 ron now??  I've always just put in Sainsburys Super which is BP Ultimate at a lot cheaper price!!  Also tried Shell whilst I was up at Wolverhampton (since my fiance lives around there) and that didnt make any difference whatsoever!! :lol:  I'll stick with Sainsbury's until I know otherwise

[Top Cat]

Hi guys and gals

I've recently just bought a MK5 GTI on a 55 plate and since owning it, I've noticed its running lumpy and sometimes rather hesitant..  I did have a misfire on cyclinder 1 a week ago but they changed out the coil pack on cyclinder 1 and it seems to be ok, but its still got the lumpyness and hesitation...

Its more so at lower revs, upto 2000rpms or so, seems to be like a jack in the box at times!! :lol:  I just wondered if anyone knew what might be causing this problem, because its going into the VW Garage for an MOT on Thursday, but they'll have the car from Wednesday night to check it all over for me.  If have some ideas of what could be causing the car to feel like its holding back that would be ideal.  since the hassles I had with my GT TDI with them, they wanna keep me happy or else they'll have the keys back!!

I know I'm driving it rather light footed at the moment as when I mentioned I was getting over 38mpg the reaction I got was shocking!! :lol:

Any suggestions or thoughts would be great   Thanks in advance

If your getting 38mph then it wont matter what you put in. 

[Teutonic_Tamer]

Hi guys and gals

I've recently just bought a MK5 GTI on a 55 plate and since owning it, I've noticed its running lumpy and sometimes rather hesitant..  I did have a misfire on cyclinder 1 a week ago but they changed out the coil pack on cyclinder 1 and it seems to be ok, but its still got the lumpyness and hesitation...

Phill, VAG-COM will be your friend.  If you don't have it, then ask the garage for a copy of the printout of all the stored fault codes - otherwise you could just be guessing, and replacing unnecessary parts.  Just as important, make sure the garage CLEARS all the stored fault codes, otherwise, even if they've replaced any offending parts, the stored fault codes can still make the engine run like a bag of . . . .

Its more so at lower revs, upto 2000rpms or so, seems to be like a jack in the box at times!! :lol:  I just wondered if anyone knew what might be causing this problem, because its going into the VW Garage for an MOT on Thursday, but they'll have the car from Wednesday night to check it all over for me.  If have some ideas of what could be causing the car to feel like its holding back that would be ideal.  since the hassles I had with my GT TDI with them, they wanna keep me happy or else they'll have the keys back!!

An MoT, particularly if its done at a main stealer, won't specifically check for any non-MoT faults!

I know I'm driving it rather light footed at the moment as when I mentioned I was getting over 38mpg the reaction I got was shocking!! :lol:

Any suggestions or thoughts would be great   Thanks in advance

Start giving it some beans - it may simply be coked up, and need an "italian tune up"!   

[Teutonic_Tamer]

lumpy idle is normal (within reason)

Hmmm . . . can't really agree with that.

incorrect boost I wouldnt normally link with a coil pack though.

Again, can't agree.  If the sh@gged coil pack has stored a fault code, then the engine will run in "limp home" mode, which will cut turbo boost.