156 JTD engine problem

[johnalfasud]

Hi, I was wondering if anyone can throw any light on a problem have with my 156 2.4JTD (150bhp, 60k miles).

The engine produces hardly any power below (usually) about 2000 rpm, sometimes its so bad in 1st gear it won't get above walking pace, and the throttle response is virtually non-existant. Once it gets above a certain rpm, it goes like normal. It's not consistent, although it seems to be worse if at steady speed for a while, then slowing and trying to set off again. Sometimes, it doesn't even go until about 3500 rpm, and the only way to get into busy traffic is build the revs up and slip the clutch all the way! When it's struggling, it chucks loads of black smoke out the exhaust and this clears as soon as the power comes in.

My local Alfa specialist has looked at it a few times but is at a bit of a loss now. Nothing shows up on the diagnostics, and they changed the AFM but this made no difference. They reckon the turbo and actuator are working as they should.

I'm tearing my hair out!! Any advice greatly received!!

[egomeister]

Faulty exhaust recirc valve?

[silverback mike]

Mine doesn't do a great deal below 2000 revs, but not as bad as walking pace, but over 3000 it goes like hot snot. No smoke deposits though.