Advice needed from fault diagnosis experts (LCR)

[Russellg911]

Hi

I have a 54plate LCR with approx 13k miles on the clock.

For a couple of months the car has been having imtemittent episodes of sluggish running. The main symptoms are:

Spongy throttle response when on the move (it's normally very crisp and takes off like a scalded cat even at half throttle)
Lacking progressive pull above 4krpm (i.e feeling held back) but then a sudden snap of boost (as if something has come unstuck and freed itself)
On occasion there is no turbo 'nudge' at 2.5krpm and the normal whistling sound of the turbo cannot be heard as the car pulls through the rev range.

So far I have done the following:

Seat dealer done a check for fault logs - nothing found, keys handed back.

I unplugged the MAF and went for a drive - not a great deal of difference - car felt smoother but a bit down on power. The following day I plugged the MAF back in and after a day of driving the car felt fantastic - very responsive and pulled swiftly through the rev range. It made me realise how it should be. That same evening I done a vagcom run with Mark (mork) and all seemed fine; the MAF showed good readings. Then after a few days the car lost it's edge again and has been on and off since. The car was recently vagcom'd again for a couple of hours driving and again no faults were logged and all readings appeared normal. One thing we noticed however was that there was a very fast regular pulsating 'clicky' sound coming from the engine part circled in the pic below:

Am I right in thinking this is something to do with the EGR? If you touch one of the pipes near the circled object the clicking sound stops - the other day though it could be heard from inisde the car. Does anyone have any idea what may be causing my car to feel like it does? This has really got me scratching my head and although the car is reliable (i.e always starts ok, doesn't kangaroo or stall), I do feel there is a problem that needs sorting and this is not a case of having got used to the power.

As a side note, the car generally pulls well when flooring it through the gears (although this is not my typial driving style) and is always very crisp and responsive the first time I put my foot down on my journey home from work - the car then (normally) becomes sluggish after. I've noticed that manipulating the throttle on and off (once past 4krmp) can sometimes 'snap' the boost back into place. This is definately not turbo lag and is like something becoming unblocked.

Thanks for any help and all the people that have answered my PM's so far.
Russell

 

[CupraSteve]

sounds like the car is going into limp mode
the clicking is normal

 

[m0rk]

the clicking is just part of the carbon cannister for emissions. and is normal

when we reset the adaptation values & went logging that worked. but it was on 95ron until you got him I guess.

it's a real head scratcher though.

 

[Russellg911]

Ahhh, ok well at least I know the clicking is normal thanks guys.


Mark, that night when I got back I filled up with Optimax - it was during the 3 days that followed that things turned a bit sour again ....I have done a manual TBA since but the glory of how the car ran that night has not repeated itself. It's been up and down like I say but has not once gone back to feeling as good as it did that night (which is how it used to be all the time).

 

[Ruddmeister]

It all sounds to me still like an intermittently faulty MAF. I used to have days where it felt great then 90% of the time it felt like I'd left the handbrake half on.

Lack of fault codes, the way the car runs etc all still says MAF......any chance of borrowing a MAF from at a meet etc just to try on the car??

 

[CupraSteve]

try following pabs cleaning guide for the maf

 

[Russellg911]

Hi Steve (Ruddmeister), thanks for replying.

Since this all started I suspected the MAF as being a possible cause. The fact that after 6 or so weeks of running pretty poorly, the car snaps back into life the day after I unplugged and plugged the MAF back in. Either that is a very extreme coinicidence or is related to the issue.

CupraSteve - thanks, I may give that a go, I'm willing to try anything mate.

I've not been to any of the meets yet, I want to turn up to one with a car that's running nicely

 

[Ruddmeister]

If you do try the MAF it's fairly cheap IMO about £70 on exchange, give dealers a wide berth go to German Swedish French or Eurocarparts etc....unless the car is under warranty in which case they (the Dealer) will probably replace every part in the engine first (because 80% of them are clueless tw@ts)

£5 says it a intermittant fault on the MAF

 

[Russellg911]

Thanks Steve. I did ponder the idea if unplugging the MAF again, letting it log a code and then inoccently approaching another dealer to see if they will exchange the MAF as a freebie under warranty(?)...bad idea?

 

[Ruddmeister]

Thanks Steve. I did ponder the idea if unplugging the MAF again, letting it log a code and then inoccently approaching another dealer to see if they will exchange the MAF as a freebie under warranty(?)...bad idea?

No sounds good to me, if it's on a code on the screen they can't go wrong........probably

 

[Russellg911]

Cheers....did you have a MAF problem on yours then Steve?

 

[vern]

Has the car been remapped?

you will probably solve it with Maf or new N75 valve( boost solonoid)

 

[Russellg911]

100% standard Vern.

I thought a dodgy N75 would perhaps log a code of some sort??

 

[Ruddmeister]

Cheers....did you have a MAF problem on yours then Steve?

A couple, one caused by me though

 

[vern]

100% standard Vern.

I thought a dodgy N75 would perhaps log a code of some sort??

No mate just like mafs, dont always log a fault unless they go open circuit, if it sticks it will hold the wastegate open longer etc you maybe alble to see this on a boost log if it jumps around, but not always

 

[Russellg911]

Could you detail a bit more about your symptoms? How did you conclude the MAF as being the prob mate?

 

[vern]

Could you detail a bit more about your symptoms? How did you conclude the MAF as being the prob mate?

Because i told him

 

[rst_cupra_r]

coould it not b an actuator or would tht throw up a fault code

 

[vern]

coould it not b an actuator or would tht throw up a fault code

The actuator is controlled by the N75, and the N75 is much cheaper and more likley, the actuator is integrel to turbo on k04, and the full turbo will be swapped under warranty if it were that faulty

 

[Ruddmeister]

Could you detail a bit more about your symptoms? How did you conclude the MAF as being the prob mate?

See post #5

Main thing was lack of any fault codes though and general feeling of lethargy (car not owner)