This Stilo is really starting to hack me off now! I've just spent all afternoon changing the front discs and pads, just went somewhere in it and it's flat as a fart and will not pull, as if it's in limp mode.

Scanned it with FES and it's not threw up any codes and the EML isn't on. Tried driving it with the MAF disconnected and it was a lot better, so I presume it's that. I tried to take it off to clean it, but the bottom bolt will not come out - it's just turning around, so I presume the housing's knackered.

Is the car ok to drive about until I get a new MAF with it disconnected (I may as well just replace it rather than clean it)? There is now a light on the dash with the MAF disconnected, but it's a lot more drivable.

Yesterday, I had the glowplugs replaced at the garage to sort the 'preheat' message I was getting, but I don't see how this could have affected the MAF or done anything else to send it into limp mode.

It seems like you go one step forward, two steps back with these! Oh, and I'm still no further with the airbag light :bang:

Sodding Fiats!!

dude, if you were closer i would offer to give you a hand, Fiat's are frustrating cars at times haha

I know exactly how you feel, i've had two faults re-appear - airbag failure and now preheat fault! I had a problem similar to yours with the power loss and it ended up being the egr valve, so you could try that. You said it drives better without the maf connected but maybe worth looking at the egr valve too.

What have u tried to get rid of the airbag fault? Mine was the ocs then a loose wire under driver seat. Did changing the glow plugs solve the preheat fault? Did you get the fault on every start up? Mine was fixed with a new wiring harness from heater relay module to each glow plug, first time round. Don't know what is it now though.

Phil

I'm 90% sure it's the MAF sensor - it's definitely in limp mode with it connected, it struggles to get to 50mph. With it disconnected it's still not quite right but is able to drive normally. I'll have a look at the EGR when I change the MAF.

The preheat fault was traced to number 2 glowplug going down, so replacing this cured the fault.

All I've done with the airbag is clean the orange connectors. I've been trying for ages to scan it using FES, but it cannot detect the airbag ECU despite the correct pin being selected. Mine doesn't have an OCS mat. My local garage couldnt connect to the airbag ECU either, so it looks like I'm going to have to get it scanned at Fiat.

Oh, and I've not even started trying to diagnose the 'alarm fault' message that's started appearing every startup.

This power loss issue still isn't sorted. I've changed the MAF for a new one (a simple job that took ages due to corroded fixings). The car is no longer in limp mode with the MAF connected, but has the same power loss issue below about 2500rpm, at which point it picks up as normal.

I thought it may be the EGR valve being clogged, although it's not kicking out any smoke, so that was going to be my next move.

However today the EML came on and it's generated the code P0236 Overboost Valve signal low (intermittent). What is this and is this a symptom of the EGR or something seperate?

A friend of mine is having this problem, not much power below 2500rpm then BOOM!

The turbo is slow to spool up then suddenly just before 2500rpm it boost like crazy.

I took a quick look.

New turbo less than 12 months old.
No boost leaks.
Small pipes to and from the boost solenoid are fine.
No error codes stored.

Got me stumped.

Fault code P0236 relates to the turbocharger boost sensor (circuit range/performance), not the valve (solenoid). The sensor that controls the valve is the MAP (Manifold Absolute Pressure) sensor. It may just need cleaning.

Right, yesterday I blanked off the EGR at the manifold, tried to clean it but couldn't get it off, so just ended up cleaning the pipe from the EGR to the intake and the intake itself. I also removed and cleaned the MAP sensor.

The problem is still there, no power then get to 2500-3000rpm it boosts as normal. At one point it threw up codes P0235 and P0236 (previously it has just logged P0235) so my last guess is it's the boost solenoid, so I've ordered one today, but apparently it has to come from Italy so will take about 5 days. If this doesn't work then I may well get rid of the thing!

From previous experience with those error codes the first thing I replace is the MAP sensor, 9 times out of 10 it solved it.

Twincam1986 said:

The problem is still there, no power then get to 2500-3000rpm it boosts as normal. At one point it threw up codes P0235 and P0236 (previously it has just logged P0235) so my last guess is it's the boost solenoid, so I've ordered one today, but apparently it has to come from Italy so will take about 5 days. If this doesn't work then I may well get rid of the thing!

Click to expand...

P0235 fault code indicates the engine boost limit is not being reached, ie a low signal
P0236 Is a MAP sensor code.

I've had both fault codes on my old JTD resulting in replacement of the boost solenoid valve.
Whilst the MAP sensor will be providing the control signal, it is the solenoid that controls the vacuum that operates the turbo - if it gets a low signal, it wont regulate the vacuum.
Its a common fault on Stilos and is often caused by the solenoid getting wet - it has a very fine mesh and diaphragm that suffer when wet. Both of my failures were caused by nearside puddles! Solution is to fit a new one, but resite it - I've already published a guide on resiting to the side of the battery box.

I'm surprised that the part has to come from Italy - its such a common fault that most Fiat dealers carry them in stock - normally about £45

If you have access to a a vacuum pump/gauge (or perhaps a big syringe) you can manually operate the turbo - connect the vacuum pump to the pipe going to the turbo, tuck it safely under the bonnet and take it for a spin - you can get some quite spectacular performance!:devil: I wouldnt recommend driving like this for too long though

Thanks, Ive read your guide, that's where I got the part number from (55203202). I ordered it last Saturday and it's only come in today. And it was £85 not £45! Just hope it solves it. I'll post when I've had a chance to fit it.

hi, i have a problem similar to yours. Had error codes for the egr valve and maf sensor, and a hole in one of the turbo pipes. got it all replaced with brand new ones. also changed the oil and fuel filter, new air filter, changed the oil and cleaned the map sensor.
Result. im still only hitting normal power once i get to 2500rpm and MPG is down to 38. its bad that buses and cabs pull out at the same speed as me on roundabouts unless i put my foot all the way down, or start reving a bit more than i should before i let the clutch go.

also my clutch seems to be knackered.

AT LAST!! :slayer:

Replaced the valve and the car now drives as normal again. Took a while, but I got there! Thanks for all the suggestions!

I also re-sited it, although it's just zip-tied in place for now as someone's borrowed my drill and not given it back