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(Post Link) post #1 of 8 Old 29-03-14 Thread Starter
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Help required on Turbo on 20v 156

Hi all,

The garage looked into my performance on my car and found actuator is jammed and not moving. They have tried to free it up, but only made a little difference, but the MCF light / warning no sounds.

Feels like turbo is not kicking in. Mileage is 163k.

Engine also shudders when turned off.

I had suspected the Vacuum pipes, and they have been checked. The garage have reported that the pipes are ok, and Vacuum solenoid is operating.

They suspect the VNT mech is jammed.

I have asked for the turbo to be stripped and cleaned, but they are not too keen, preferring to recondition the turbo. They are confident they can do this themselves?

A few questions:

1. What is the Turbo model of the Garrett fitted to the 20v 156 JTD's?
2. What is the original ALFA part no?
3. I have seen threads / video's of the Mr Muscle and Innotec cleaning method? Would this free up the actuator or VNT? Is it worth trying?
4. Could it be a faulty actuator unit?
5. Can the 20v turbo be reconditioned? - I have read different views on this?
6. Can the intake manifold be cleaned I situ?

Anyone near Nottingham with experience?
Unfortunately I do not have cable to read the error codes?


04 156 2.4 JTD SW Veloce
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You should be able to test the actuator in situ, just remove the clip and disconnect the actuator rod and apply some vacuum with a length of tubing and a syringe, the rod will move if the actuator is working.
If the turbo is a Garrett Gt series as is used in most of the jtd's. I dont know what was used on the 20v 156, then with the turbo off the car you can separate the exhaust turbine housing from the rotating assembly which will give you access to the vnt mechanism to see what is wrong.
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156 20v is equipped with GT2256v.
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(Post Link) post #4 of 8 Old 29-03-14 Thread Starter
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Thanks or the help guys.

Anyone know if the turbo can be rebuilt reliably by the garage?
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156 2.4JTDm

No it can't. But they may have a local specialist in mind.
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Shuddering when shutting down can be deposits in the butterfly valve not allowing it to shut completely. Take off the flexible turbo intake pipe and give the valve a wipe. Or take off the valve entirely and clear out the muck!

I would be very wary of using Mr Muscle, that's what buggered my turbo.

It you remove the small tube that goes to the solenoid from the vacuum pump, you should be able to feel a vacuum, if that's OK then check to see if there is a mark on the VNT where it has been moving. If not try by-passing the solenoid, if the VNT works then it is the solenoid - assuming you have a vacuum.

Brilliant Blue 156 GTA SportWagon | Q2 | KW V1 Coil-overs | Eibach ARB | Wiecher Strut Bar | Wizard Cat-Back

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Last edited by TOX1C; 29-03-14 at 22:35.
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(Post Link) post #7 of 8 Old 30-03-14 Thread Starter
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Thanks Tox1c.

Speaking to the garage - the mechanic has told me that the he checked vaccum readings and they were fine. He has said he was unable to move the actuator by hand and it was jammed.
Not sure if this means it is the actuator itself, or the VNT that is jammed.

Di you get a new turbo in the end, or was it rebuilt? If so who rebuilt it? I have read Midland Turbo - not sure about their guarantee though. It seems if the Turbo blows up after they have rebuilt it, then the fitter / car fault is blamed.

Can the VNT mechanism be cleaned without having to rebuild / balance the turbo?
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I usually go for a new core, after the VNT is cleaned and inspected. Most of the time I reuse the VNT. Just changing the core(125, they usually come with gaskets) and fitting a new VNT(60 off fleabay) Would make a reliable turbo, but the VNT mech can be worn and cause problems later. Yours is a fair milage, but these turbo can easily cover 250000miles+ if looked after, thats why I recommend getting a good mechanic to strip n clean the bits to assess the most relaible root! The money you save on a complete turbo could be put towards a EGR delete? I wouldn't rebuild it like replacemant bearings n stuff. Just follow good practice when first using the car again until the turbos settled in, I left full details in my other posts
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156 , 20v , required , turbo

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