Brief Power Loss on Quick Acceleration

[Bigus]

Hi

I have a THP155 and every so often, when I'm accelerating quickly, I get a momentary loss of power causing the car to jolt. It's always happens at the higher end of the revs while accelerating and given that I never take the revs above 4K in any gear I would estimate it's occuring between 3.5 and 4K revs and probably in 3rd gear.

One time it happened a noticed a cloud of darker smoke come out of the exhaust at the same time, but it's only done that once.

Rather annoying this as my previous car (an MG ZT turbo) had a similar issue and I never got to the bottom of it!

Has anyone else had this?

Regards
Bigus

[Ragnarok]

No OCC installed or PCV deleted?

At least for me PCV delete and OCC got almost rid off this... probably detonation / misfiring...

[Chris_Blue]

Take it in and get it looked at under warranty
What fuel you use?

[Bigus]

Thanks for the replies.

Is the OCC/PCV thing some kind of mod? I haven't had anything done to the car.

Petrol-wise, I just use standard 95, mostly from Sainsburys!

A couple of other things I have noticed is that there is a little engine oil pooled on top of the engine and definitely not spillage. I wonder if there is oil leaking somewhere it shouldn't when the engine is under pressure. The other is that my coolant level has gone from max to just above min in the header tank and it was probably about 3 months ago when I topped it up to max. I don't think I've ever had a car that hasn't required occassional topping up of the coolant though, so maybe that's just normal.

Bigus

[Dangerousfish]

Thanks for the replies.

Is the OCC/PCV thing some kind of mod? I haven't had anything done to the car.

Petrol-wise, I just use standard 95, mostly from Sainsburys!

A couple of other things I have noticed is that there is a little engine oil pooled on top of the engine and definitely not spillage. I wonder if there is oil leaking somewhere it shouldn't when the engine is under pressure. The other is that my coolant level has gone from max to just above min in the header tank and it was probably about 3 months ago when I topped it up to max. I don't think I've ever had a car that hasn't required occassional topping up of the coolant though, so maybe that's just normal.

Bigus

Get it to your dealer ASAP.

There's a number of threads on the same issue posted here.

If left too long this could result in an engine failure.

http://www.ds3club.co.uk/showthread....5-Acceleration
http://www.ds3club.co.uk/showthread....ion-cold-start
http://www.ds3club.co.uk/showthread....THP-power-loss

[lfcrule1972]

Mmmm - I'm not sure about the oil, I think I read about that in other posts on the forum, you could see if a forum search turns up anything useful. Sorry to not be more helpful I own a diesel so have no experience of the THP155

Good luck

Ah Fishy beat me to it !!!

[Chris_Blue]

Oil on top of engine isn't great- positive pressure means its being pushed out from somewhere
Sounds like a little bit could be being burnt too. something could be leaking somewhere

Never heard of it on a 155, happened to a few 150s tho- get it checked

[Bigus]

OK thanks, I've booked it in for tomorrow morning.

What is that "HPFP" you speak of in one of those threads you linked to, Dangerousfish?

If it is the timing chain it sounds a bit like the dealer isn't going to be immediately inclined to fix that! Interesting that they used metal timing chains - I wonder if that explains why the engine sounds a bit noisier/rattly while idling than I was expecting.

I'll be sure to ask what exactly they fixed when I get it back too!

[cyclone]

What is that "HPFP" you speak of in one of those threads you linked to?

High Pressure Fuel Pump

[Dangerousfish]

OK thanks, I've booked it in for tomorrow morning.

What is that "HPFP" you speak of in one of those threads you linked to, Dangerousfish?

If it is the timing chain it sounds a bit like the dealer isn't going to be immediately inclined to fix that! Interesting that they used metal timing chains - I wonder if that explains why the engine sounds a bit noisier/rattly while idling than I was expecting.

I'll be sure to ask what exactly they fixed when I get it back too!

If the answer is that they've simply tightened the chain - This isn't a fix.

Ask them to put down in writing that they're happy this fix is sufficient to resolve any future issues that may incur the same symptoms and if not that they'll provide you with a full refund.

[ds3r]

Oh dear it's happing to the 155 s now

[Chris_Blue]

First one of this Ive heard so far. Theres been turbo problems and HPFP problems
Not heard of timing chain/tensioner issues as yet
But lets see. Be interesting to find out Citroens diagnosis

[Ragnarok]

Oil on rocker cover seems faulty sealing or pressure escaping due to something being blocked...

Coolant fluid is either burning or leaking. If there is no coolant under car, then it is burning? White smoke from exhaust? Failed gasket?

[Fooda]

Lol .. this is the the second DS3 to have the same symptoms as mine, it seems that they can't solve this issue with the engine. My theory is that the oil vapor has blocked the PCV and intake and that just starts destroying the engine.

Mine is about to turn 3 years old, it has the same symptoms as this one and it got worse, now my engine feels down on power and it leaked oil two times (first time the same as in this thread, the other time was a big leak from the bottom of the engine).

I don't know about a PCV delete and i think it's better to leave the PCV and just put an oil catch can, and a good one.

At first I just thought the heat in my hometown got to the engine but it seems to have nothing to do with hot weather :P

[Ragnarok]

Lol .. this is the the second DS3 to have the same symptoms as mine, it seems that they can't solve this issue with the engine. My theory is that the oil vapor has blocked the PCV and intake and that just starts destroying the engine.

Mine is about to turn 3 years old, it has the same symptoms as this one and it got worse, now my engine feels down on power and it leaked oil two times (first time the same as in this thread, the other time was a big leak from the bottom of the engine).

I don't know about a PCV delete and i think it's better to leave the PCV and just put an oil catch can, and a good one.

At first I just thought the heat in my hometown got to the engine but it seems to have nothing to do with hot weather :P

I would imagine you Saudis could afford something better than a DS3