(T) heres one for the techies "engine fault"

i guys well ive finally got the lovely "beep beep beep" engine fault, this all happened after i had clean my BMC CDA induction filter but i some how think that is irrelevant to the problem thats going on because i ran the engine with out the filter on and still engine fault.

It came on the other day after a very short drive and stays on, later the same day i got in the car to check it out and WOW it had gone. i drove around a little bit being very cautious and nothing. Get in the car in the morning and walla no fault drive a good 10miles ( she was very unpredictable) fill her up with petty and what would you know the engine managment light came on when i restarted.

I took it to a mate who read the codes on an EBOD II system; ( foolishly i forgot to write the codes down !! ) But what i can remember is it came up with;

- o2 Sensor circuit malfunction
- coil failure

i did a test on the coils and there is no indication of change in engine tempo. so i have ruled the coils out.

well down to the engine running, it starts fine and runs ok for a second or two, but then seems to be missing a beep and struggling to keep the engine revs. seems as if it is getting close to stalling but then regains tempo. exhaust sounds like it spluttering.

well i hope some of you guys have a slight indication of the fault, my self diagnosis of the fault is the top lambda. but im not entirely sure. dont want to go out spending £60 on a new on to find it does not sort the problem.

cheers ppl

Indeed it may be the Lambda sensor and you have two of them one on manifold and one in the cat ..maybe you picked up some of that bad petrol that's been going around I had a similar fault but that was an injector and engine light went out after three start ups ..but came back on when the fault reoccurred spos you have had the usual updates done to the throttle body/ecu ? and had a look if the throttle body flap valve might need a clean

If you suspect the lambda sensors, then you could try disconnecting them in turn.

This will force the ECM to revert to default values and not use the 'strange' value of a defective sensor.

The engine power will be down and mpg will change, but it should run better than you describe. The beep beep beep will still be on, as you have disconnected the sensor itself.

Try it, it may improve matters. If it does nothing then it points away from the sensor itself.

i cleaned the throttle body valve a month ago, had a look to see if it had clog but it is squeaky clean. Im sure it can'nt be the petrol cause i only use shell's petrol. :lol (unlesst the contamination was wider spread than first thought) as to the updates as far as im aware they have been carried out, i had the pleasure of taking the stilo to FIAT on monday to have the safety recall carried out on the springs.

whilst i was there i asked if it had all been done. the guy said yes ( but he never actually checked the car, unless its all on a database somewhere)

i've just been out at the car and have run the engine with the top lambda sensor disconnected it seems to idle better, but obviously there is still engine management light on ( obviously because it is disconnected or because the problem is somewhere else) plugged it back in and wow the engine begins to struggle again. even tried the legendary contact cleaner on the connection..

always knew you'd be around PNL, as usual very helpful..

This could be a few things, but it sounds like your car is going in to "limp home mode" That means its losing a sensor signal or the signal on a sensor is going out of range. You could also have a simple air leak around the throttle body, and this would make the Map sensor work incorrectly, and make the engine run richer and effect the lamba. Could also be a fault or bad connection on the cooling temp sensor.
Take the car to a proper diagnostic centre like Bosch, and not Fiat. You need an emission reading to show if its over fueling or not, and a OBD reading for faults. They can also read if the lamba 02 readings are stable or fluctuating, which would indicate a fault there. Incidently, your lamba when cold is not in the loop, so if its a lamba fault, car should run fine cold.

Andy.

Thanks for that info Andy even coope owners are usefull some times

Being a constant Fiat owner over the years, you tend to find out the pros and cons of the cars. And we know they have a few cons don't we!!
I tell you what, around my neck of the woods, there are loads of Stilos!! Most seems to be silver for some reason though?? And there is a very nice Candy red met Abarth Schumacher GP that is tempting me to buy one!!

Andy.

interesting thoughts andy cheers for that, i will go have alook around the throttle body to see if there are any leaks.

As to the diagonostics, at the moment im looking for an OBD II reader so i can run software on my laptop to see the information for myself. seems to me like a worth while purchase giving the oppotunity to pin point problems with out pay a garage to do it.
Does anyone know if i should be buying an interface for the ELM323 chip. im just a tad confused as there are a few out there. (it might be me just being very blonde)

welcome to the Massive

My problem though, is all the faults with some Stilos. They are either ok, or full of faults. Iam in the motortrade, so i get to here on the grapevine too.
An Abarth with 200bhp upgrade would be nice, but and its a big but, iam still worried about all the problems these cars can potentially have!!!

Andy.

I just like 5 minutes ago had the engine fault light, like 3 times in a row, im reluctant to move it till it's gone, i also on the 2nd time starting it got a 'high coolant temp' but on the 3rd try starting it was'nt there anymore? just the 'engine fault'!?!?

Should i top up the coolant then? or dissregard the msg?

note: this was after i had a flat battery and had been charging it over night, and just had put it back in the car?

Shaun, I recently bought an ELM327 usb reader box and that works fine with my 1.6 Stilo. I thought the 323 would be OK, but got the 327 for a few quid more to make sure!

Derek

brilliant cheers for that mate..

Oh back to the car, its bugging me now. would a lamda sensor be giving the same kind of signs that a coil failing would give? i.e spluttering exhaust on idle, mis-firing.

When testing the coils there is no indication that any have gone. As on reconnecting the cables the engine note changes and you hear the cylinder start up again.

heres another question, if a spark plug was to foul could that pull up a fault with a coil. or do they have there own fault codes? this engine is really confusing me..

as i stated in my first post the fault reader pulled up the o2 sensor fault and the coil fault. but when i test the coils i notice a change in the engine on each one. so i seem to be pulling blanks.

Not surprised you're confused, your car was talking to you, telling you what was wrong and you didn't listen ie make note of the fault codes.

Quickest answer, take it back to your mate and get the new logged fault codes.

If a coil fails then they tend to go out big time ie nothing- so you'll know all about that with a total misfire on one cylinder. Easy

There is no fault code for coil failure- it will identify cylinder misfire or random/multiple misfire so you may not have a coil gone

There's a whole bundle of fault codes for O2 sensor and you have two sensors on yours

Find out what codes are logged and make your life easy
Here they are
P0130 O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
P0131 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)
P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
P0134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
P0135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
P0136 O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
P0137 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)
P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
P0140 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)

Sparks
P0300 Random/Multiple Cylinder Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected
P0304 Cylinder 4 Misfire Detected

So it will pinpoint which cylinder is at fault or whether its a general misfire

If it says O2 sensor problem and a misfire then that's what you have. Trust it. Otherwise it becomes a guessing game