poor runner..!!??

[Guss]

HI Guys..
Great new Sub thread makes things so much easier..
ok, I a
have just developed what i believe is a strange issue with my Signum and wonder if there is someone who can advise me..
Car has been running beautifully, no smoke and smooth as ou like.
Since the 5 jan i have had to travel t stafordshire stone to be exact to do training for my new job, this is a 400 mile round trip.
I first noticed a problem when i tried to do am overtaking manovere, my car being an auto, i expected it to kick down and take off...needless to say it didnt..
Instead it felt like teh brakes had been applied and as the revs started to climb ( very slowly and stagered ) the car jolted given a sensation of a car being push started and disengaging the clutch but the car not starting..for those who have not expeiienced that it caused the car violently shake..
Since then i have noted that, the car when cold is ok to about 50 miles an hour with slow excelleration..
when hot the car starts to hold back a4 40 miles an hour.
The hesitation is found in rev range of 2k to 3k.
After jolting and stuttering the car will briefly cure itself and excellerate like a bat out of hell the judder again.
When the car judders white smoke ( atomised un burnt diesel ) is expelled quite alot and leaves clouds easily visable in the rear view mirror.
However again the fuel economy over the 410 miles travelled yesterday car returned 48 mpg.
I have replaced the fuel filter, done 8000 miles.
I have cleaned the MaF sensor. also have inspeced teh air filter which semed pretty clean again 8000 mile old / 6 months..
Any ideas much appreciated

Russ

[merikiito]

Turbo pipes/ intercooler leak perhaps

[Guss]

Thanks Merikiito..
I will go and have a nose now
in addition to my first post and referring to your poCAR:
PREFACELIFT/FACELIFT* Prefacelift
TRIM: Heated electric leather
YEAR: 2003
ENGINE: y30dt
MILEAGE: 127000

Russ

[merikiito]

Trim was meant to be SRi/GSi etc but its nice to know you have a warm butt lol

[Guss]

LOL..that made me laugh merikiito...
But yeah it does help in this crappy weather..mind you only when the car runs right...
so i guess my trim will be Elite in that case

[gtr1000]

Have you had diagnostics on it to see if there's any fault codes?

What mileage on the engine Guss? Edit - I need to read the posts more closely, 127k.

[Guss]

Hi GTR1000

No not have any fault code diagnostics run on it, mind you no fault codes have come up, or safe mode for that matter
will there still be fault codes?

[Celes]

I had the same fault mate, 3 times for 3 different reasons.
1. fouled fuel filter
2. water in diesel
3. suction control valves
The only difference to yours would be the colour of the smoke...mine smoked grey-black

I would suggest you replace the fuel filter again, add some anti water additive thing to your tank and see what happens.

[gtr1000]

No not have any fault code diagnostics run on it, mind you no fault codes have come up, or safe mode for that matter
will there still be fault codes?

Without codes, this is tricky.

You could start with the free and simple things like removing and cleaning the MAP sensor and the air temperature sensor in the inlet manifold, followed by the EGR. The EGR removal is time consuming but might be worth it just to eliminate EGR faults from the equation.

There's also a VX field remedy for the EGR, basically an ECU update, which is specifically aimed at engines with the auto box, when the EGr is heard to be "whoosing like a steam train". Only available from a VX stealer though.

Remember, we're all here to help as much as we can with this V6 lump .

[Guss]

Cheers guys...will start the process of elimination over the weekend..
I had problems with black smoke a ew months back, my car was under warranty still..so took it back to the garage where the guy has blanked my egr valve and apparently reprogrammed the car to not see it..
Phase one will be new fuel filter