Technical Multipla JTD lumpy to 1500rpm???

[Jeztom]

Hi all, first post so please excuse if i do something wrong.......

I have a 2005 55 plate Multipla JTD which I really like.. excellent family car.
The only thing spoiling my experiece at the minute is when the engine is cold..it is very lumpy up to 1500rpm where the vibration is at its worst. This causes the whole car to vibrate..above 1500rpm, there is no issue at standstill.
On the move and after warming up the issue gets better but not totally. I also feel it is down a bit on power throughout the rev range as if it is being restricted/held back?
My local dealer has had a look, but put it down to possibly a blockage in an injector? In turn i bought some injector cleaner and used it but no improvement. Surely, if it was an injector then the engine would perform the same throughout the rev range?
The dealer also run a diagnostic test on the car which brought back no faults :bang:

Any help would be appreciated.. I have read about the egr valve but my symptoms dont quite fit the bill..

Thanks in advance

Jeztom

 

[demag]

Does it take long to clear? Might possibly be a duff heater plug.

 

[Jeztom]

Hi Dave,

Thanks for the reply, not sure if it makes a difference but it never does completely clear, just gets less of a vibration.. above 1500rpm it is ok..
The only time it is noticed is when at standstill or pulling away from junctions..

 

[JTDman]

Id check your cambelt , it may have jumped a tooth knocking the timing out.

 

[Eccy]

Hi Jetzom,

I've got exactly the same problem with my '54 1.9 JTD, its been running lumpy at lower revs and occasionally cuts out when I'm backing out of the drive. Seems ok at higher revs, but stays noisey at the lower end, even on long journeys (6 hours). My local garage owner thinks it might have sucked up some water through the air filter and advised me to bin it, as the cost of getting the engine fixed might run into thousands!

I hope he's being a bit pessimistic, and he advised I get it checked out by a diesel engine specialist.

I've never driven it through a high flood, just some hefty puddles

Let me know how you get on in your investigations, and I'll do the same.

 

[martyc5674]

I've this problem aswell.
It's only noticeable at standstill if bringin the revs up or down slowly.

Can anyone confirm this is not normal for JTD 115??
Everything else seems perfect..good mpg no smoke.
Maf and egr both ruled out .. Changed oil and filters today even did a diesel purge with liqui moli diesel purge.
Did the cambelt and aux belt and all pulleys not that long ago.

Would like to hear if it's normal or if anyone has worked out what causes it.
Could it be dmf???
Marty.

 

[momoe]

The only other sensor that occasionally causes issues is the MAP sensor, this measures manifold pressure. It's on the inlet manifold (to the o/s of the EGR) and does get clogged.

Other than that check the vacuum boost hoses, these can go hard after a while especially at the ends and cause vacuum loss.
Easy way to check is get someone to start the car while looking at the actuating rod on the turbo, should move about 20-25mm, when the car stops it will return slowly.

Worth replacing these with silicone if they're ******ed:
http://www.ebay.co.uk/itm/ws/eBayIS...130487484132&ssPageName=ADME:B:EOIBSA:GB:1123

 

[martyc5674]

Ok I'll pull out the MAP and see if it clogged.
The turbo actuator is moving in and out but thanks for the tip on the slow return.

Would the turbo be providing boost below 1500?
Marty.

 

[slobo]

Maf and egr both ruled out .. Changed oil and filters today even did a diesel purge with liqui moli diesel purge.

Marty.

Have you blanked off the EGR?

 

[martyc5674]

I have indeed slobo...

The turbo actuator I'd say takes no more than a second to return after engine has stopped. But it seems to go back damped if u know what I mean... Too quick???

Also it doesn't seem to move when engine is revved... It travels about 20mm on startup and returns on shut off but I had the missis rev it slowly to about 3500 and it didn't budge....
Haven't had chance yet to get map out.
Marty

 

[slobo]

Can you see if it's throwing up any codes? Cam or crank sensor maybe.

 

[martyc5674]

No codes...been like this a good while.
Have you a jtd??
If you wouldn't mind slowly bringin up the revs to 2000 and back down when stationery and reporting if you have any rough spots.
Cheers
Marty.

 

[slobo]

With the snow we got this weekend I cant even open the door!!

 

[martyc5674]

Ah no worries!!
Any other takers to see if they have this llrough spot???
Thinking of resetting the ECU to see if it helps.
Could well be injectors but that ain't cheap!!!
Marty.

 

[slobo]

Marty, I dug it out today,
No rough spots at all, Mines done about 125,000Km's
I only tried it cold.

 

[Devious]

Ah no worries!!
Any other takers to see if they have this llrough spot???
Thinking of resetting the ECU to see if it helps.
Could well be injectors but that ain't cheap!!!
Marty.

Unplugging the ecu does nothing except clear any fault codes you may have.

 

[martyc5674]

Cheers...at least i know im not after a red herring!!

Going to try get the MAP out tonight if i get a chance(unlikely!!)

Been doing a bit of reading and in fairness its pointing towards injectors.

The car is absolutely perfect other than the rough spot when unladen...laden its absolutely fine.

Cheers,
Marty.

 

[martyc5674]

Unplugging the ecu does nothing except clear any fault codes you may have.

Does it not also set the ECU up to relearn your driving style etc etc??

I was thinking maybe a previous owner did a reset while there was a fault present...

Marty.

 

[Devious]

No. Merely clears codes.
How long have you had it/how many miles covered?

The ecu is progressive so re learns the second you start driving as your style will be different to the previous owner. 500miles and the car has learned your style

 

[martyc5674]

Ok thought it onlidsid the learn thing after a reset.
I've had it over a year..just hit the 100k mark and I've put 12k on it.
Think the slight lumpiness been there all this time.
Marty.