Technical Yet another Stilo engine fault message

[Orangey]

Hi everyone,

I have read quite a few threads on the forum about the "Engine Failure" message on Stilos, but can anyone help with my situation? I have the 03 Stilo 16V aircon model. A few weeks ago I turned the ignition and the car stalled, with the error message "Engine Failure". If I started the engine again and gave it some more revs for about 30 seconds, the car was driveable. Took it to my local mechanic who plugged in the OBDII diagnostic tool and it came up with manifold (something beginning with A - sorry cant remember) pressure sensor error - or MAP sensor. Got this replaced (I think it was a a non fiat replacement) and car drove great for a week. Went to start car up this morning and same thing happened - stalled on starting, same error message, needs more revs to get car driveable after 30 seconds or so. just taken it back to mechanic who plugged OBD in again - comes up with same MAP sensor error!. He says he will replace it free of charge as it might have been a duff sensor? Is this common do you know? Is it likely to be a duff sensor or is something else likely to be at the root cause of all this? I've noticed recently that when the car idles, the engine noise seems to change pitch from high to low - not really noisy or anything but a definate change in pitch - could this also be related in some way? Would appreciate any thoughts/suggestions.:worship:

 

[hanzs]

Did you cleaned inlet control valve as first step? ... see guides...

 

[Deckchair5]

Crap mechanic.
Anyone who just changes the MAP sensor or any item just because the fault code is saying there's a problem with the MAP sensor circuit is given 0/10 from me.

There still IS a problem with the MAP sensor circuit, your car knows it and is telling you so but your mechanic is particularly dense in not realising it

It needs a running graphical test on the MAP sensor output whilst in operation to see what the car is spotting. It will often give freeze frame data of just what and when it's happening and what figures are making it trigger. A simple bad connection would give the same fault code

If the car drove great for a week then did the same again it obviously isn't the sensor and there was probably nothing wrong with the first one


Here's a typical MAP sensor error where the car spots 109Kpa which is more than atmospheric pressure at the time so it triggers a fault but it's ahead of itself as the car has no rpm at the time of the freeze frame

The cure here? Clear the fault code and monitor it to see if it's ok (which it was)

You have something up with the MAP circuit which needs to be running data monitored whilst car is being driven

 

[Orangey]

Hi Deckchair,

clearly my current mechanic isn't up to the job.
I may as well let him fit the new sensor as this presumably will clear the error message for me?
But what sort of mechanic do I approach for the running diagnostic - an engine diagnostic specialist of some sort or just someone who generally tunes engines?
Presumably someone with the relevant diagnostics software?
Does anyone know of someone I could trust in the Sheffield/South Yorkshire area?

 

[Deckchair5]

The only way to clear that fault code is to physically clear it either with a fault code reader/software or disconnecting the battery for an hour or so will clear the lot

The same fault is extremely likely to happen again within a short time of fitting another MAP sensor

For running data, it doesn't need a specialist, just someone who can connect to the car's OBD to see what is happening to the outputs when the MAP sensor is put through its paces on a normal drive

You can check a MAP sensor pressure v voltage but that takes a vaccuum pump with gauge and multimeter

Maybe time to consider obtaining some relatively cheap diagnostics gear as it will save time and money enormously

 

[Orangey]

Thanks for coming back to me Deckchair.
If I buy into the diagnostics gear what do I need for the Stilo?
Im not sure I would be able to interpret the findings having no mechanics background or does the diagnostics make it pretty easy to identify the issue?

 

[hanzs]

Diagnostic is the most helpfull instrument, but as you mentioned - right interpretation of the data is the real "knowhow"...
Try find experienced mechanic.

 

[Deckchair5]

From simple plug in fault code readers to full graphical engine data outputs there's everything available these days

Best way is to familiarise yourself with using it and then ask on forums for others opinions of the data you have, then you're really plugging into the goldmine

If nothing else you will know more of what's going on and not so likely to get ripped off. Cars just get more sophisticated so you need to keep up

The people who will survive are the people who can do and fix things and not need someone to fix it for them. That means bankers, politicians and stock brokers will be the first to perish, you see there is a grand order to things

 

[hanzs]

Deckchair5: I agree with you, but not everybody has the talent or enough time to start learn car diagnostic.

 

[Deckchair5]

not everybody has the talent or enough time to start learn car diagnostic

Unfortunately that's also true for poor quality mechanics who look at a fault code and then simply change the component at your expense. Anyone can do that and a lot cheaper

 

[Orangey]

As always, thanks for the good advice Deckchair - and Hanz!
Question now is what to start with - I have seen OBDs for about £60 - Deckchair you signposted me to a dealer previously.
Is that the best way to go first?
Although I am a bit confused - my mechanic used an OBD device to diagnose the MAP sensor. Would that device have given more information that he has missed and should have identified- and that I could read off and then check with forum users?
Or does the OBD just tell you that a map sensor is at fault and nothing else - in which case am I better off getting some sort of software that I can upload to my laptop?
I can fix bicycles but not much good with cars as you probaably gathered!

 

[Deckchair5]

Thing is that there's always someone online to help you once you have the data to hand but the more limited the information then the more guesswork it becomes

If you just want a plug in device to read fault codes and erase them and resetting your ECU then there are loads of those on ebay

If you want to read sensors as the engine runs then you need an interface to connect your laptop to your car. You need an OBD type connector and software like Gendan or a VAG COM type connector and run FiatEcuScan. If you modify the VAG connector then you can read ABS and airbag fault codes with FES. If you have the latest version OBD connector then you can reset the engine check warning and a few other items with FES

Once you can connect to your car then you can read fault codes and all available engine sensors

It sounds bewildering but it all depends how far you want to go. Most start small and then go deeper.

What do I use? Most of the time, bluetooth interface with OBDgauge on my phone. Absolute magic. But that's a bit special