MK1 LCR Dumping Early

[Lee1892]

Hi Guys,

Driving my LCR today and it's started hesitating and dumping boost while my foot is still planted.

I can be accelerating and I can hear the filter sucking in, then it starts hesitating, the DV dumping and turbo chatter. That's without even lifting my foot off!

Does it whether foot planted or half throttle under acceleration.

Scanned it and no codes are showing at all.

Anyone got any ideas?

 

[Dave_c85]

Could be a split pipe dumping the air, in turn causing the DV to dump due to pressure loss. Does it happen once boost reaches a certain amount, or does it hold boost then dump?

Sent from my LG-H815 using Tapatalk

 

[Lee1892]

Could be a split pipe dumping the air, in turn causing the DV to dump due to pressure loss. Does it happen once boost reaches a certain amount, or does it hold boost then dump?

Sent from my LG-H815 using Tapatalk

Sometimes you can hear it starting to dump as it hesitates, other times it can hesitate then dump.

It can happen 3 times during one accelerated gear change. So into 2nd gear, foot down then 3 times dumping before it gets into 3rd!

 

[eddie_cupra]

I have the a similar issue but its only when cold and on light throttle. It hesitates slightly then feels and sounds like it loses boost pressure. Seems like its either opening the DV or the Wastegate for some reason to dump pressure. But there should be much boost (if any) as like I say its cold and I'm only just pottering along. When warm its fine.

My thoughts are it could be one of these:
A split boost pipe somewhere allowing unmetered air in or causing the N75 to malfunction - but it would be the same (if not worse) when hot? I've looked and found nothing obvious so I'll discount it for now.

Sticky/malfunctioning N75 - causing waste gate fluctuation?

Plugs - cold engine = more sensitive to weak spark?

Ignition coils - as above. These are known for dodgy coils and indeed were recalled for them. I'll get this done first as its free and a likely cause I think. Hopefully my cars not already been recalled for them. Will change the plugs too while I'm at it as don't know when they were last done.

MAF on the way out - but I would expect to see it at other times too and all readings from it seem to suggest its fine. Will have to remember to monitor it from cold...

Brake light switch - A less obvious one but a common(ish) failure. Usually it just causes the brake lights to stay on flattening your battery over night (ask me how i know..). If its faulty and giving an occasional false brake signal to the ecu it will open the wastegate (as should happen under normal breaking). Again I would expect to see this at other times though.

Maybe some of that will give you some ideas...