re s40 enine managment light

[520222]

Hi can anybody shed some light on my troublesome volvo it's and s40 2001 51 plate drives lovely then the engine managment light comes on and stays on,

this doesn't effect the running and the car still drives ok we plugged it into a snap on diagnostic machine reset it and the light goes out and can stay out for as long as 2 mths or will come back on next day it also does go out on it's own accord and stays out for days or weeks,

i,ve had it plugged in when the light stays on to read the codes and each time it comes up different codes ie air intake bypass valve low fuel pressure bank one and slight misfire cylinder 4 i,ve spoken to my local volvo dealer who tell me the valve timing is out and it needs a cambelt and adjustment to PROBABLY sort £350.00,

Now logic tells me if the timing as out it would stay out and the car would run like an ole knacker which it doesn't b4 i spend fortunes on hours of diagnostics can anybody HELP PLEASE Many Thanks Dan.

[Jocksuper7]

right what you need to to do is get the codes read, and let us know what they are, the t4 has hessitaion issues that are spark plug Dependant and there are issues with the MAF breaking down, get an obd11 reader and let us know what the codes are there is enough peeps here that can give you a better heads up, if you let us know where you are there may be someone nearby that can read them for you

[mharriso]

timing out... i thought this was set... with the spark advance / retard adjusted automatically by the ecu taking readings from the crank and cam position sensors amongst others etc... i would be looking for intermitent fault on these two sensors first....

i would not be spending a penny until the codes are read though... as advised...

[Andru]

Thanks for the suggestions.It is still in the garage at the moment as they don't have time to look at it untill this afternoon,hopefully it wont be to expensive.
I've had the car for nearly seven years,apart from having the two belts changed and consumables, this is the first time it has gone wrong.

[Andru]

I have not long had the car back and the problem was a faulty thermostat temp sensor,which led to the fan coming on and over heating plus much more.The cost was £190 all in which was basically a sensor fault.I had to have a new sensor,new thermostat,new plugs because they had sooted up too bad and also the battery packed in!

On the way home from picking it up the engine light came back on so i had to go back to the garage who reset it and showed me the problem to be the second lamba sensor after the cat.It has all sooted up because of the way the car has been running.Can i remove it and clean it or would it be better to get a new one and also where is the cheapest place to get one from.

Cheers

Glad its all sorted now

[CTCNetwork]

Hi,

Originally Posted by Andru

On the way home from picking it up the engine light came back on so i had to go back to the garage who reset it and showed me the problem to be the second lamba sensor after the cat.It has all sooted up because of the way the car has been running.Can i remove it and clean it or would it be better to get a new one and also where is the cheapest place to get one from.

Cheers

Glad its all sorted now

Surely you can burn the carbon off as the temp in the cat does get high enough to do so.
May take a good long run with maybe a high rev session (see italian tune-up)

Des. . .

[gnhuk]

It should "self clean" if you run it in a lower gear than normal (i.e. keep the revs up aka "Italian Tune Up") - you'll probably notice a rotten eggs smell while this is happening.... happened to me anyway