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Model specific boards => Golf mk4 => Topic started by: Procomp on 20 June 2012, 15:42

Title: Rough Running 1.8T....Advice Please
Post by: Procomp on 20 June 2012, 15:42
Afternoon
I'm looking for some advice or previous experience/posts on a rough running engine issue I have with my 1.8T.

Yesterday on the way home, I stop at a shop to buy some groceries and the car was fine, then when I got back into it and pulled away, suddenly it started to labour and struggle to pick up.  No warning lights or notice, just running really badly and sounding like a flat 4!!

I stopped and checked undereneath/under the bonnet to make sure nothing was wrong and from the visual inspection, I couldn't see anything.  I was still able to drive the car home ( a further 30 miles) and apart from it being really judderly off the line and the fuel consumption going down drasically, I was able to make it home safely.

Does anyone have any ideas as to the best places to start to look as I know it could any number of things, but thought it was worth looking for someone wiser than myself on VW's to see if there was anthing worth looking at first. 

As I said, I have no warning lights and apart from poor running, the car still goes.  Would the exhaust have anything to do with the poor running?  It's an Milltek Cat back system, which is a new part, but it's been on the car for 500mls??

Thanks for your help
G


Title: Re: Rough Running 1.8T....Advice Please
Post by: rio_gti on 20 June 2012, 15:45
lambda sensor fallen out?  :undecided:

need a but more detail..... first things first get it scanned!!!
Title: Re: Rough Running 1.8T....Advice Please
Post by: scarr89 on 20 June 2012, 15:46
MAF suddenly went? Unplug is and see how it drives...If it drives worse then it isn't the MAF  :grin:
Title: Re: Rough Running 1.8T....Advice Please
Post by: golf-sib on 20 June 2012, 15:48
My monies on a boost leak due to poor mpg with judder, could also be MAF, I'd check both out first.
Title: Re: Rough Running 1.8T....Advice Please
Post by: Zayd on 20 June 2012, 15:48
The exact same thing happened to me.  It turned out to be the MAFF (Mass airflow sensor).  Cost around £85.00 and once fitted, the car was back to normal health.
Title: Re: Rough Running 1.8T....Advice Please
Post by: Procomp on 20 June 2012, 15:52
Thanks for rapid responses everyone..........

Couple of questions:-

Where's the plug for the MAF ?
Is there an easy where to test for boost leaks?

I'll scan the car now to see if there are any fault codes occuring and let you know.

Cheers for now
Gregg
Title: Re: Rough Running 1.8T....Advice Please
Post by: rio_gti on 20 June 2012, 15:54
the maf is connected to the air filter box, the plug is on this!!
Title: Re: Rough Running 1.8T....Advice Please
Post by: rio_gti on 20 June 2012, 16:00
(http://i1092.photobucket.com/albums/i408/rioracer/Untitled.jpg)
Title: Re: Rough Running 1.8T....Advice Please
Post by: jamie1989 on 20 June 2012, 16:03
Pro comp what engine code do you have mate?
Title: Re: Rough Running 1.8T....Advice Please
Post by: Procomp on 20 June 2012, 16:12
It's an AGN
Title: Re: Rough Running 1.8T....Advice Please
Post by: Procomp on 20 June 2012, 16:14
AGU..........Typo user error lol  :grin:
Title: Re: Rough Running 1.8T....Advice Please
Post by: Procomp on 20 June 2012, 16:20

Unplugged the MAF......didn't feel any difference either way really.  Just as bad tho :sad:
Title: Re: Rough Running 1.8T....Advice Please
Post by: golf-sib on 20 June 2012, 16:29
Boost leak on either, TIP, pancake pipe or elsewhere on the vacuum system
Title: Re: Rough Running 1.8T....Advice Please
Post by: jamie1989 on 20 June 2012, 16:30
When you drive the car under load does it feel really flat?
Is it missfiring at all?
Title: Re: Rough Running 1.8T....Advice Please
Post by: Procomp on 20 June 2012, 16:48

It struggles to get off the line and is really lumpy but I wouldn't say it misfires at all.  It will get up to speed eventually and on my run home I go on a motorway and it would do 70mph etc

It more just very rough running off the line, lack of acceloration once going and poor mpg performance

Title: Re: Rough Running 1.8T....Advice Please
Post by: Procomp on 20 June 2012, 18:51
Hi
Everyone......I just wanted to thank everyone for the advise and guidance.  Found my VAGCOM and tested the car and found this fault code: -

(http://i1078.photobucket.com/albums/w494/Gregg_Castree/MAF.jpg)

Order a new part now so hopefully, this will resolve the rough running issues.

Really appreciate the help  :smiley:

Cheers
G
Title: Re: Rough Running 1.8T....Advice Please
Post by: jamie1989 on 20 June 2012, 19:18
Iv got 2 spare mafs if needed mate? I can post first thing tomorrow morning too if you like?
Title: Re: Rough Running 1.8T....Advice Please
Post by: cullygti on 20 June 2012, 19:31
how much the maf jamie
Title: Re: Rough Running 1.8T....Advice Please
Post by: Procomp on 20 June 2012, 19:36
Jamie
I've already ordered one....bugger :grin:

Thanks
Gregg
Title: Re: Rough Running 1.8T....Advice Please
Post by: xxChrisxx on 20 June 2012, 20:00
I don't want to piss on anyone's bonfire but, spot the obvious flaw in this plan.

Unplugged the MAF......didn't feel any difference either way really.  Just as bad tho :sad:
Quote
(http://i1078.photobucket.com/albums/w494/Gregg_Castree/MAF.jpg)

I'd see if you can cancel the order and just do a bit more investigation.

Try resetting the codes (and disconnecting the battery for 30mins or so). This will reset the ECU trim values.
I'd put money of it being the lambda sensor over the MAF. Have you got the car mapped?
Title: Re: Rough Running 1.8T....Advice Please
Post by: jamie1989 on 20 June 2012, 20:11
Cully pmd mate
Title: Re: Rough Running 1.8T....Advice Please
Post by: Dalo Harkin on 21 June 2012, 07:56
From what you have described I would say one of the coils have gone, easiest way to test is start the car unplug 1st one, engine revs should drop, plug that one back in its fine, do all 4 and if one doesn't drop its fooked
Title: Re: Rough Running 1.8T....Advice Please
Post by: jamie1989 on 21 June 2012, 08:02
Wont be coil packs on agu dude. Ignition amp is more common.