TD4 lumpy start up and pinking under load

I thought I had seen something on this recently, but I searched for a while and can't find an answer.

When I start the engine from cold it idles around the 1000rpm and is very noisy and lumpy. It then settles down and is fine after a minute. Is this okay as I'm sure it has recently started doing this.

The other is like a 'pinking' under load. Even my wife commented on it the other day. Never noticed it in other diesels I have had. Is this normal?

Vehicle 2006 TD4 s/w HSE
Current mileage 115,500.

Mods done to TD4 Auto:
PCV Dyson type fitted.
EGR bypass.
Red Silicon hoses (all 5)
Pierberg MAF
Ronbox currently with power turned off but MAF on.
Pipercross air filter
The injectors I was told were 'done' before I bought the car.

try putting 2 stroke oil in the fuel tank, approx 200ml to 250ml to a tank full.

Not a joke, works really well. Have a search on here about it and you'll find I speak the truth.

good luck

Thanks.

What does it do?

acts as a cleaner of gunky deposits in fuel system

When I start the engine from cold it idles around the 1000rpm and is very noisy and lumpy. It then settles down and is fine after a minute. Is this okay as I'm sure it has recently started doing this.

Click to expand...

if you could see the fuel flow at cold startup ..
you'd notice the flow if slightly higher than if the engine were warm / hot ..
i'd guess the ecu adds a bit more fuel to the 'mix' at cold startup
( the ecu reads the coolant temp. .. and air intake temp ..
( to calculate how much fuel to inject ..
( a.f.a.i.k. it uses coolant temp only .. for a cold start ..

i've an 'litres-per-hour' gauge .. via a scangaugeII ..
can monitor the fuel flow from cold startup ..

other things come into play as well .. to up the flow .. and sometimes idle rpm ..
like alternator load .. a.c. usage .. pti heater if fitted ..
e.g. ac usage will up the fuel flow but not effect idle rpm ..
pti heater usage does up the rpm slightly .. compensating for alternator load ..

I thought it sounded maf related then realised you had a pierburg maf fitted. From experience, this maf only works with the box turned on, and running over half max. Does it run better with the box on and turned up?

I've had the same problem for over a year, tick over not to bad but the pinking is. Funny thing the pinking only happens about 40% of the time. Rest of the time it sounds normal/quiet and smooth.

It happened with the original bosch MAF, i bougt a ron box and a pierburgh Maf and it still does it. Cleaned all electrical connectors on fuel rail and injectors, still doing it. Had a leak back test done and number 2+3 are leaking back 1+4 are fine. I managed to get 2 brand new injectors but have yet to get them changed, hope it will cure the problem.

i get some *slight 'pinking' sound on partial go-pedal .. ( *hardly noticable )
i.e. when the engine is not under much load .. heard at lower rpm ..
normally vanishes with added go-pedal and turbo boost ..

( edited to add ) .. with mine it seems to only happen once the engine has reached full operating temp.
and sounds like a very low key version of normal diesel clatter ..
on a cold day .. after about 15 miles .. on a hot day much sooner ..
might have something to do with the air to fuel ratio ..

~~~~~~~~

it's caused by how the fuel burns :

http://www.landyzone.co.uk/lz/2176872-post16.html

~~~~~~~

i imagine excessive 'pinking' might be caused by fuel quality
injectors out-of-spec .. the overall condition of the head and valves ..
out-of-spec turbo operation .. ..
the timespan the injectors are 'open' as controlled by the maf signal a.f.a.i.k.

i take it that the 'pinking' is the td4/m47r version of 'diesel knock'
on older designs .. the diesel knock really sounds like a knock or clatter ..

What is pinking ?.

freelandie71 said:

What is pinking ?.

Click to expand...

The sound you get from a petrol engine when it is under load like in too high a gear.

Only I have a TD4 and have the pinking sound.

Prime example earlier today, 50 mile round trip sounded fine on the way there smooth and quiet. Way back pinking its tits off, from a standing start sounds like a sewing machine starts to go around 2500 rpm

Optimus Prime said:

try putting 2 stroke oil in the fuel tank, approx 200ml to 250ml to a tank full.

Not a joke, works really well. Have a search on here about it and you'll find I speak the truth.

good luck

Click to expand...

What about Millars ecomax for diesel?
Doesn't that do the same?

I'm currently using BP Ultimate. Normally use bog standard shell fuel save. Never use supermarket fuel. Learnt lesson years ago.

Epicuser said:

What about Millars ecomax for diesel?
Doesn't that do the same?

I'm currently using BP Ultimate. Normally use bog standard shell fuel save. Never use supermarket fuel. Learnt lesson years ago.

Click to expand...

Forgot to mention i have been using both 2 stroke and millers since day 1, has made no difference to the random pinking problem

I had same problem between 1500 _2000 rpm turned out to be fuel rail pressure sensor wiring harness , took me 20 minutes to fit , all ok after

What was wrong with the fuel rail pressure sensor wiring harness?

Hi dog-man found it by chance, engine ticking over I moved the harness and it caused erratic running at tick over , having taken harness of the vehicle I did a test on each wire and one was breaking down on movement , got anew harness from indie for £35ish

Optimus Prime said:

try putting 2 stroke oil in the fuel tank, approx 200ml to 250ml to a tank full.

Not a joke, works really well. Have a search on here about it and you'll find I speak the truth.

good luck

Click to expand...

Synthetic or mineral?

mineral

Epicuser said:

Synthetic or mineral?

Click to expand...

low ash mineral, doesn't need to be anything fancy.

somewhere like wilkinsons or tescos sell a suitable one

Noticed this morning when I was looking at the auxiliary belts, that when I started the engine to turn the steering to full lick, that there was a lot of white smoke and a diesel smell coming from the engine compartment under the wheel arch. . It stops after a moment or two.

I've noticed the strong smell of diesel a few times recently.