Loss of power 159 JTDm 2.4

[AndrewK]

Hey guys,

Our 159 2.4 diesel is lacking power down low, and has twice now suddenly lost power on the highway, which necessitates pulling over and restarting. Fuel consumption has also deteriorated.

Turbo boost is fine (according to the gauge) and we've taken it on plenty of long trips, which means the particulate filter is probably OK. After browsing Alfaowner, it would seem the prime suspect is the EGR valve.

Have  any 159 owners experienced this problem?

Cheers,

Andrew

[Craig_m67]

What error codes come up after scanning the ECU
Or.. What does your mechanic say?


Because it could be any number of things, including the EGR.

[colcol]

I am waiting for an expert to reply, so seeing there aren't any, here's my 2 cents, clean the EGR Valve, Colin.

[Craig_m67]

Or...
If the car is fitted with a DPF (series 2 onwards?) then force a regen (if possible)
Check the condition of the battery in case it is failing under load (load test! not just voltage at idle) - common problem, ends most goose chases
Check the crank sensor is working (first failure is intermittent and happens when hot, cold start fine)
Check for split boost hoses (after turbo, after inter-cooler)
Check for a gunked up MAP sensor (like EGR)
Check for gunked up swirl vales in the inlet manifold (like EGR)
Check for a blocked fuel tank pressure equalisation valve (causing fuel starvation and error/limp mode)
Check the variable vane solenoid on the turbo works

I could go on

Get the ECU scanned for any error codes that might point you in the right direction. Given the symptom (sudden loss of power) points more to an intermittent fault/failure, I'd start with the battery, crank sensor, fuel. My money is on the crank sensor causing the stops and the general malaise being gunked up EGR/MAP and swirl valves. Dodgy batteries have been known to cause all manner of errors too, the ECU is very susceptible to voltage spikes.. Or a failing regulator in the alternator providing too high a voltage at speed...

Any other symptoms, unusual things noticed ?

[AndrewK]

I spoke to my mechanic today, and he thought it may be the EGR valve and possible fuel supply problem. What is unusual is that when it loses power on the freeway the car is not displaying any warnings.
RE reading the codes. Does this need a laptop, AlfaDiag and the appropriate cable?

[Craig_m67]

If your mechanic can't read the ECU for error codes, or didn't bother, then you need a new mechanic who can help you with a modern car.

[AndrewK]

LOL I merely spoke to him, I did not take the car to him.

[phri]

I had a very similar situation with my 159 1.9jtd, I cleaned the MAF sensor and the EGR valve, installed a new fuel filter, airfilter and installed a flow restricting EGR gasket. Together probably 2 hours work (at least for the first time)

Now, I have a decent amount of low revs grunt.

btw, car is manufactured in 2008 and while serviced by alfa dealer, fuel and air filter had never been replaced !! (based on date stamps filters)

[AndrewK]

Thanks phri.

I dropped the car off to my mechanic (Arnaldo & Pino in Hornsby) just before Christmas. EGR valve was choked up but there is an issue with the turbo.

Will update when I get the car back.

[Mick A]

I have seen the rubber hose on the boost side become damaged by a radiator hose clamp that is poorly positioned near it and when it expands under boost it slices the intake pipe.

[AndrewK]

Thanks choder, I will take a peak at that too.

[AndrewK]

Well. It turned out the engine was choked right up with soot (EGR valve, turbo, particulate filter). Cause - worn linkage for the intake manifold butterflies leaving at least one of them open at all times. Quite an idiosyncratic failure I would imagine, especially for a car with only 70K kms. In any case, goes brilliantly now.

[soldiiier]

Could you elaborate a little mire about the flap problem? Thanks

[AndrewK]

Having just read Evan's post on another related thread, I believe the "butterflies" are actually swirl valves and that the problem lies in worn linkage ball joints.

[Matthewpl]

Hi Andrew
I just heard about Arnaldo and Pino in Hornsby. Do you recommend them?
I have recently bought a 2007 159 2.4 JTD and would like a few things looked at.
Thanks
Matt