How much should a 3.0 V6 CDTi smoke?

**neverton** · 9th March 2010, 14:15

Hi,
Might seem a strange question, as I know it's a diesel car, so should smoke a little, but how much is a little?

Only reason I ask is that I was coming down the A49 yesterday, from Shrewsbury to Ludlow, got stuck behind a VW Polo with Miss Daisy driving and a couple of lorries behind her, so found a nice straight spot, floored the accelerator, bit of a delay, then car shot off like a scolded cat, really did move!! went from 40 to 80 in no time, looked in the mirror and there was a massive cloud of dark grey smoke across the whole road!

Not done it since, seems to drive OK, so not sure whether or not it was something blocking something somewhere or ????

Car's a 2005 Auto with 60k on the clock, Full VX service, etc.

Only thing I have noticed is a small judder at 1500rpm which the dealers are looking into, we both seem to think its the SCV (field remedy 1957 I think) but we're giving it a couple of weeks as I am busy driving around so need the car. I did pop some Millers fuel system cleaner through it, on a recommendation, so whether its thats dis-lodged something I'm not sure.

The judder at 1500 is still there though

**Celes** · 9th March 2010, 15:12

It shouldn't

Simple as that

As for the injector cleaner I would not reccomend to use it if you've never used it before. Your issue here seems just like what I had last year. Huge grey smokescreen and judder around 1500rpm. Replaced the injectors and all is well.

**neverton** · 9th March 2010, 15:22

Originally Posted by Celes

It shouldn't

Simple as that

Lol, that answer my question nicely thanks

Originally Posted by Celes

As for the injector cleaner I would not reccomend to use it if you've never used it before. Your issue here seems just like what I had last year. Huge grey smokescreen and judder around 1500rpm. Replaced the injectors and all is well.

Will mention the injectors to the dealers, see what they think as we'd both pretty much narrowed it down the the SCV's lol

TBH I've nearly always used diesel cleaners in most my cars, I did put it in this one when I first had it, but hadn't used any lately as the judder was more obvious without the additives in the fuel system (as I wanted the garage to be able to recreate it) unfortunately I forgot last time I filled up and put the additive in

I was actually out and about enjoying the weather and trying to use some diesel so I can take it in to the dealers again!

Strangely though the car seems a lot better now, hardly any smoke even under heavy load, MPG seems to have gone up (just got 38mpg which I've not had that high before), so will keep an eye on it for a couple of weeks, got a few miles to do next week so should give my more chance to try and recreate the judder and smoke (always nice to find an excuse to floor a V6

)

**monty2000** · 9th March 2010, 15:22

how often do you open up the car?
if you dont very often you most probs cleared out some crap

**neverton** · 9th March 2010, 15:23

Originally Posted by monty2000

how often do you open up the car?

erm, every 1 or 2 miles

Depends where I'm going, I am quite heavy right footed and quite an impatient driver, so normally overtake (safely!) anyone doing less than say 50 in a 60 limit the speed limit (I'm talking open A roads here, not around towns, etc.)

**Celes** · 9th March 2010, 15:58

SCVs shouldn't cause grey-ish smoke. I think user m8internet reported thick black soot when they were really shot.

**m8internet** · 9th March 2010, 16:36

Originally Posted by neverton

floored the accelerator, bit of a delay, then car shot off like a scolded cat, really did move!! went from 40 to 80 in no time, looked in the mirror and there was a massive cloud of dark grey smoke across the whole road

Not done it since, seems to drive OK, so not sure whether or not it was something blocking something somewhere or ????

Car's a 2005 Auto with 60k on the clock, Full VX service, etc.

Only thing I have noticed is a small judder at 1500rpm which the dealers are looking into, we both seem to think its the SCV (field remedy 1957 I think)

That was exactly what happened to me on my trip from Scotland to Newport, via Loughborough
As I went to leave Charnock Richard the car "struggled" to 40mph, then woomph up to 80mph, along with masses of smoke when the power returned
It gradually got worse over the next 200 miles

By the time I got back the car was struggling between 40 and 60

So it may be the beginning of the symptoms of a blocked SCV

As your dealership says, give it about two weeks, by then the symptoms should make it clearer if it is indeed that issue
Equally, get them to order the parts NOW, as there is backlog on SCV (I waited several weeks)
I assume the car is out of warranty? If so, get your blankety blank cheque book out, but you may be able to encourage VX to make a contribution if the car has a full VX history

At this stage DO NOT use any injector or fuel system cleaners
You really need the problem to get worse and not be intermittent
Once the diagnosis has been made and parts ordered, then you can try "fuel system treatment / cleaner" (note it is NOT injector cleaner)
TESCO used to sell "Diesel Fuel System Cleaner", at just £3 per 250ml, but it is now discontinued
BP stock a similar product, but it is not on sale to the general public
The nearest I have seen was from a local Motor Factors, at £18 for 500ml
I've not even seen any in Halfords
An alternative is to use "2 stroke oil" to thicken up and help lubricate the fuel pump (quite sure someone could recommend a product)

**Penfold101** · 9th March 2010, 16:41

The vibration at around 1500rpm is possibly the timing belt. Mine did this but went away when the belt and tensioner were changed at 90K, and I believe other people have found the same solution worked...

**neverton** · 9th March 2010, 17:00

Originally Posted by m8internet

I assume the car is out of warranty? If so, get your blankety blank cheque book out, but you may be able to encourage VX to make a contribution if the car has a full VX history

Hi,
Only had the car about 10 weeks, it was purchased with a full AA gold warranty which covers the fuel pump, injectors, etc. but even if they don't cough up I did notify the dealer of the problem within 3 days of taking ownership of the vehicle, so I will expect the dealer to pay for the work if they try getting the AA to pay first, and the AA refuse the claim.

I've had about 10 cars from the same dealers (and same salesman!) so he better be nice to me if the AA won't!!

**neverton** · 9th March 2010, 17:03

Originally Posted by Penfold101

The vibration at around 1500rpm is possibly the timing belt. Mine did this but went away when the belt and tensioner were changed at 90K, and I believe other people have found the same solution worked...

Yeah, have read soooo many posts about the V6 CDTi, trying to arm myself for when I took the car into the dealers on each occasion. We've both decided to try field remedy 1957 in the first instance, as this can be detected via tech2 when the problem manifests apparently. Whereas not sure if injectors and timing belts can be so easily tested without replacement, haven't asked the dealer TBH.