Help - Very strange air intake / boost leak running issue

[jedi-knight83]

Background... Car is 2005 58k DSG. Stage 1 remap.
Drove down to Somerset on saturday no problems. Ran low on fuel and only fuel around was morrisons regular unledded so I put £20 of that in to get me the rest of the way. Did about 50-70miles on that and then parked it for the weekend and didnt use the car again till tuesday night at midnight when i drove home.

First thing I did was filled up with V power and then with nice empty roads I set the cruise to 85 and stayed doing 85 for about 2hrs till we hit 50mph road works... slowed down but had it in manual so stayed in 6th.

Accelerating out of the road works in 6th it then started getting strange!

-There was loads more intake noise... it sounded like my mates twintake. Ive just got a normal air box set up and has never heard it that loud
-There was hardly any power and the revs were jumping up and down a bit when i accelerated rather than a nice smooth increase like normal

We were almost back at Enfield to drop my mate off so I just came back slow. Had a look under the bonnet to see if any obvious pipes had come off.

I decided to head home anyway and see how it went... pulling out from my mates there was still loads more intake noise than I am used to... pulled up to some traffic lights and there was then a strange, reasonably loud pop / bang .... it sounded a bit like a bit of hollow metal being dropped. Bearing in mind its now 3am and no one is about I guessed it was a noise from my car. I thought a bit of my exhaust had falled off so I pulled over to check but it was all fine...

Got back in to drive home again and all of a sudden the car was fine... plenty of power again and in 6th from 60mph it pulled nice and smoothly now.

I still think the intake noise is a bit louded but not as loud as it was in the short bit of the trip where the power seemed to vanish and the revs got all lumpy.

Took it to the garage today and there was an intermittent fault logged with the air intake / injector... I'll try to get the proper fault code tomorrow and post it up.

Anyway... little bit puzzled now!!

[Mingle]

long shot here mate my car did nearly the same but with out the load bang you heard, I found that my oil filler cap had came loose, my revs were jumping it was luggy, popping and loader.

Worth a try mate

[jedi-knight83]

Well this problem got worse to the point where when accelerating it was just juddering lots and not really going anywhere... then the engine light came on and i had to drive home in limp mode one day.

Put it into the garage and the only fault registered was with the n75 valve... which was changed and it was perfect... for a couple of days...

It felt quicker and the gear changed were alot better with seemingly no interruption in power (before there had been quite a fag before the boost kicked back in after a gear change... there is another thread on that)

just got home from a mates house (about 50 miles away) and its started doing the juddering again in 5th and 6th at low revs when you put your foot down.. it jumps about and seems 'lumpy'.

Bit worried now that its my actual wastegate thats faulty as thats part of the turbo. No other faults were registered last time so we ruled out coilpacks etc and didnt change those in the end.

[Top Cat]

coil packs dont always show fault codes. 

[jedi-knight83]

and would they cause lumpy running

[Top Cat]

Only from what i have read on here, they show all sorts of symptoms. They dont cost to much in the grand scheme of things and if they dont solve your problem, you can sell them on or keep for spares.  the other common one is the plugs. 

[jedi-knight83]

Do coil packs need the ecu to be reset?

The mechanic i use is away for a week now.

[Top Cat]

Dont think so. 

[gazbutS3]

change the plugs first

[jedi-knight83]

change the plugs first

It was given a full service at VW just before I bought it (about 3000 miles ago now). Should this still be my first point of call?

[bacillus]

It was given a full service at VW just before I bought it (about 3000 miles ago now). Should this still be my first point of call?

Yes as iirc plugs aren't changed before 60k miles according to the VW service schedule. The dealer can sometimes "forget" them even then.

[jedi-knight83]

Service book is stamped at 53911 miles for a major service and has a tick for the spark plugs. The 4 spark plugs (W06H 905 611) are on the invoice which I also have.

Regardless... I'll try changing them again... Which are the best ones to go for? Motech suggested using S3 ones?

[jedi-knight83]

From searching the forum these seem to be the plugs to go for?

NGK 7's
http://www.ebay.co.uk/itm/4X-NEW-NGK-IRIDIUM-IX-SPARK-PLUG-BKR7EIX-2667-/160627783090?pt=UK_Motorcycle_Parts&hash=item25662975b2#ht_1427wt_924

If this doesnt work I'll do the coil packs and also check the PCV which I have read can cause running issues.

[alexperkins]

If its mapped, get NGK 8s

Id be tempted to put 8s in even if it isn't. They've change my car irreversibly!

[jedi-knight83]

Its stage 1 mapped.

As i understood oem was equivalent to ngk6. ngk8 would be 2 steps cooler then? Would i need to adjust the gap?