THP low lumpy tickover when engine warm?

[Darren6645]

My wife has a 12plate DS3 dsport plus 1.6 THP. Only owned it for a month has done 28k full Citroen service
History bought from the dealer that originally sold it to the former owner. Once it's warmed up the tick over drops to approx 700rpm and the car feels and sounds like it's going to stall, it hasn't actually stalled but it
makes driving and pulling away difficult and results in her giving it a boot full of revs so it doesn't stall. It's
been back to the dealer and they said they can see what we are taking about but they say they have tried
others and they are not dissimilar. They have had it on the computer and everything is within the their
tolerances.They have sent the data to Citroen and noted the reason for our concern,so we are now waiting
for the verdict. Anyone any ideas or experienced the same?

[Toxic]

Carbon build up on inlet manifold and inlet valves

[Darren6645]

Carbon build up on inlet manifold and inlet valves

Is this a common fault with these engines or am I unlucky, is it something Citroen are aware of and I should stick with perusing it through the dealership?

Thanks.

[pmk]

Apparently it happens to most direct injected engines, there a forum thread on here about what is called walnut blasting that explains about the build up of carbon in the engine and how to go about removing it.

[pmk]

http://www.ds3club.co.uk/showthread.php?t=11149

[Darren6645]

Ok thanks I'll have a read.

[Chris_Blue]

Stick in a can of BGK 44 and use premium unleaded fuel always

[Nomgle]

Stick in a can of BGK 44 and use premium unleaded fuel always

Unfortunately this won't help - with a Direct Injection engine, the fuel doesn't touch the valves or the inlet manifold. That's why they suffer from build-up - an engine without Direct Injection has enough fuel swilling over the valves to keep them clean.
It doesn't matter what you do with the fuel system, because the build-up is caused by the oil vapours sucked from the engine.

[Chris_Blue]

It may not clean the back of the inlet valves, then again the fumes circulating the system may do
However, the additive will clean many other parts including the injector nozzles, and sensors, so wont be wasted money
And for £12.50 a can.... why not try it?
Bet it helps

Oh- catch can on front PCV pipe too... :-)

Also- Terraclean high pressure induction clean, or walnut blasting by Jamie at SPT. Threads all over the forum on these 2 methods of inlet valve cleaning

[lfcrule1972]

Darren6645 - from reading the other threads and seeing the results of Jamie and his Walnut blasting on various direct injection engines I wouldn't waste your money on any fuel cleaners now, as others with knowledge have stated throughout the threads they won't remove the carbonisation on the valves/inlet manifold.

I don't believe Citroen do walnut blasting, if they don't you could approach them and see if they'll contribute towards Jamie doing the work for you ? Good luck...

[Chris_Blue]

1, BG44K £12.50
2. Terraclean High pressure Induction clean £80-90 approx
3. Walnut Blasting £250-£300

Know where I would start first

[lfcrule1972]

I wouldn't waste money on a product that won't clean the carbonisation no matter how cheap it is

[Chris_Blue]

Cleans plenty of other parts as said- injectors/ sensors/ exhaust cat etc etc, and those area may contribute to the problem
Try the cheapest option and work up
Common sense to me...... (End)

[Toxic]

Cleans plenty of other parts as said- injectors/ sensors/ exhaust cat etc etc, and those area may contribute to the problem
Try the cheapest option and work up
Common sense to me...... (End)

more likely to be the intake tbh since there's 28k on the clock.

[Darren6645]

Thanks for the replies although not really the answers I had hoped for! Having just bought the car I wasn't
Expecting to shell more money out on engine problems, I can't believe it on a nearly new car. I will wait and see what the dealership comes back with but I'm not holding my breath.
I'm in the North east so a trip to Jamie's would be costly too.
:mad: