2.4 20v jtd jerky on part throttle

[Shaz]

Hi all,

I have had the low problem with a jerk when accelerating slowly and a slight rubbing type sound at 1800 - 2200 rpm. Also had no power at all, and then the engine light came on. This happened in early December. Took EGR off and cleaned (filthy), despite it being approx 2 yrs old (20k). I drilled the solenoid and was unable to punch it out. But the hammering action freed up the solenoid and I sprayed some degreaser inside and let it dry. Then sprayed some grease in. Also cleaned out the MAP sensor. This was also changed when the egr valve - so is the same age. The maf sensor was replaced approx 10000 miles ago.
Reassembled and he power was restored. The jerkiness at slight throttle is still there, and is now happening all the time. If I put my foot down, then power is there, no jerkiness, although the slight rubbing noise is still there at 1800-2200 rpm.


Mileage is 123000

I really hope this isn't the turbo, but how can i check? There is smoke when really booting it, but does clear after one or two hard acceleration runs. Leaving the engine idling for longish periods, I can smell burning diesel type smell.

[Shaz]

Could it be injectors? EGR? Turbo? After the initial engine warning light (before I cleaned the egr), there has been no warning lights since.

Any ideas?

[torque]

What brand is your MAF?

[Shaz]

Original Bosch, was installed by Alfa Independent.

[Shaz]

Mechanic has had a look, and has diagnosed out of balance turbo...
looks like a turbo rebuild.

[Shaz]

Right had a 2nd opinion on this. Garage (diesel specialist), thinks the turbo may be ok, checked for all pipes, and no splits. The jerky / rubbing noise is still there, although better.
Mechanic thinks it may be the EGR valve - probably solenoid.

No engine codes / error lights

[Photodave]

Elektrozawór VGT (overboost) - operation manual

I've nicked this off another thread (i'm rubbish at quoting and linking!)

dont' rule it out as a possibility - did mine on saturday and it's early days yet (the commute will determine) but delivery seems smoother particularly at light throttle and it goes like a scalded cat

[Shaz]

Thanks for that. Just got to translate it now. Any idea what language this is in?

[Shaz]

Oh. Just noticed the inbuilt translator.

Is it an easy job to take the VGT off?

[Photodave]

yes! (if you mean the solenoid) Disconnect the pipes (2 of them) and undo the two 10mm nuts holding it to the slam panel. careful cos they're on bolts - don't drop them off the other side!

polish, I think it was (and I never discovered the translator, just used the pictures!)

[alfadaveuk]

shaz just change the pipes to vnt b4 cleaning vnt out. i have 20v also and a tell tail sign of vnt pipes or the actual vnt being bad will be a judder when switching the car off. but you can change the pipes for £6 for a pack of 3 and just stretch them over the wider connectors or a tip a solder iron put it in the end switched off then switch it on then back off quick until its wide enough.
all you need is a mm split or a mm hole in any of those pipes. get some one to turn your car on and check if the bar at the end of the turbo moves should move on tick over if pipes and vnt are fine if it does not move then your problem is there. all i say is dont fix what aint broken as alfa's have a temper when you change parts or clean them if they are not needed.
check the vnt and pipes first by looking if you have movement on the actuator for the waste gate on the turbo. then move onto egr as next thing to check. is your egr a new one or a recon one???????????

[Shaz]

Originally Posted by alfadaveuk

shaz just change the pipes to vnt b4 cleaning vnt out. i have 20v also and a tell tail sign of vnt pipes or the actual vnt being bad will be a judder when switching the car off. but you can change the pipes for £6 for a pack of 3 and just stretch them over the wider connectors or a tip a solder iron put it in the end switched off then switch it on then back off quick until its wide enough.
all you need is a mm split or a mm hole in any of those pipes. get some one to turn your car on and check if the bar at the end of the turbo moves should move on tick over if pipes and vnt are fine if it does not move then your problem is there. all i say is dont fix what aint broken as alfa's have a temper when you change parts or clean them if they are not needed.
check the vnt and pipes first by looking if you have movement on the actuator for the waste gate on the turbo. then move onto egr as next thing to check. is your egr a new one or a recon one???????????

Sorry - have been busy recently (buying a house!), and have not had a chance to look at the forum.
The EGR valve I think was new - have taken this off and cleaned a few months ago. Valve itself seemed ok. Would you be able to take a picture of the vnt pipes please?

Thanks for your help.

[alfadaveuk]

i am in the process of moving house to also lol otherway around tho will never buy a house for atleast the next 10 years. renting soon. vnt pipes are very easy to find leave engine cover on an look to the slam panel where the bonnet latch is its a little grey and black device about 2-3 inch the pipes are very small vacuum pipes and the one leads to the turbo.