probs with mk4 2.0 gti, please help!

[kern]

Hi all,

need a little help here chaps, the misses has a 2002 2.0 mk4 golf gti, when it rains the car drives like sh!t, hesitates real bad, the engine management light comes on and it struggles to get pass 20mph for about 10-20 mins, then its starts to drive ok-ish, have changed plugs and leads and also had a new cat fitted as was told this was the prob, it only happens after its rained.

anyone here had this prob or know what it could be, have been told it could be exhaust but don't want to splash £300 on a new one just for it to come back!

any help appreciated.

 

[pgarner]

get it scanned first mate and list the fault codes up.

could be - maf, coolant temp sender, burst hose somewhere, lamba sensor, or worse.

cant really help more than that

 

[kern]

hello mate,

thanks for the reply, have had it on the diagnostics at VW and they said it was the leads, so changed them and still same prob, then took to another garage and they ran their diagnostics and it came up with the cat, so got that changed, was running like new for a few days until some heavy rain then problem back again!
dont really wanna throw more money on diagnostics as it cost a bomb!

 

[pgarner]

i know im not really supposed to but try looking on a vag site for someone with vagcom near you. theres more to the diagnostics than pluging in and looking at the fault codes. realistically they should be out checking out things such as the maf, fuel trims, lambda readings etc while the car is running. - unfortunately VW want to charge you a nice amount ( around £80 just to stick it on the machine and check for fault codes )

when they replaced the cat did they change the post cat lambda sensor ?

 

[kern]

they supposidly did! they said they the lambda was fine and that it was the cat (obviously the more expensive option!) feel like they ripped the missus off and like you said VW charge about £80-£100!

silly question i know but whats a vagcom? is it for diagnotics?

 

[pgarner]

yeah its basically VAG diagnostics.
it allows you to do everything that VW etc can do with their big computer
have a look here
http://www.ross-tech.com/

basically you should get away with 409 which is a free download cable costs aroud £15 from ebay - be warned alot dont work and its around £60 for the full license.

 

[Loz]

Sounds like damp in the HT leads or the coil packs on the way out. You'll probably find the problem goes away when the engine bay warms up & the damp evaporates. When the weathers damp again try spraying some water displacer (WD40) on the HT leads & coil pack & see if it alleviates the problem.

 

[sr performance]

when it's acting up again, find somewher dark, a garage preferably, leave it running and turn lights off, and you should see something resembling blackpool illuminations under your bonnet..


www.sr-performance.co.uk

evolutionchips installer

 

[pikey motorsports]

i doubt that, if he's had new ht leads why would the leads be arcing?

as said sounds like water is getting into the electricals, try spraying ignition sealant over everthing, plugs,leads, all sensors etc.

should solve your problem