Baffled but pleased!

[mikey32shaw]

Well today the beast got an oil change oil filter, air filter, and pollen filter. The baffling thing is my Engine management light had been on since buying the car and it was reading a fault in the MAF. I thought this would need replacing or cleaning and wasn't confident of doing it. Anyway after changing the air filter and taking her for a spin i realised that the engine management light had gone out :-) To say i was pleased was an understatement.

I thought though i would need to have the fault code cleared before it went out? And will my air filter been a possible cause of the problem?

Mike

[stribo]

I doubt your air filter was at fault, but when it was changed, it could have disturbed a loose connection, or the plug and now hey presto all is good. If the light does come on again just check the connections/plug to the MAF. Also although your light has gone out, the ECU will still have logged the fault code, so this will need clearing at some point.

[M-R-P]

Here's a thought...
It's the same 2.4 T5 lump a few people have had trouble with when fitting a performance air filter - Engine light on.
Maybe this problem also manifests itself when the air filter is dirty or clogged. I wonder if a performance air filter would make the light come back on.

After Volvokid's car was sorted with a TB clean, I'd like to get my hands on one of these 2.4 cars with the light on and pull all the plumbing - off for a damn good poke about.

Glad you have some peace of mind now mate, let us know if the light comes back on.

[mikey32shaw]

I doubt your air filter was at fault, but when it was changed, it could have disturbed a loose connection, or the plug and now hey presto all is good. If the light does come on again just check the connections/plug to the MAF. Also although your light has gone out, the ECU will still have logged the fault code, so this will need clearing at some point.

Will do in fact now you mention it i have been and checked the connection on the MAF and one of the clips that holds it down has snapped of one side so may be that!

[stribo]

Will do in fact now you mention it i have been and checked the connection on the MAF and one of the clips that holds it down has snapped of one side so may be that!

Yep, that'll be the problem, as it probably rattles loose when the engine's running, see if you can cable tie it down as a temporary measure.

[silverhorse]

I'd like to get my hands on one of these 2.4 cars with the light on and pull all the plumbing - off for a damn good poke about.

.

I'm on my way!!

[silverhorse]

Well today the beast got an oil change oil filter, air filter, and pollen filter. The baffling thing is my Engine management light had been on since buying the car and it was reading a fault in the MAF. I thought this would need replacing or cleaning and wasn't confident of doing it. Anyway after changing the air filter and taking her for a spin i realised that the engine management light had gone out :-) To say i was pleased was an understatement.

I thought though i would need to have the fault code cleared before it went out? And will my air filter been a possible cause of the problem?

Mike

Happy days. Codes will be stored and will need to be cleared. Does she run smoothly? No flatspots? Steady idle? Still worth giving your MAF a clean though.

[mikey32shaw]

Yes mate can feel the difference but not being that mechanically minded wouldn't know if there was flat spots but defo better :-)

[partsforvolvos.com]

Here's a thought...
It's the same 2.4 T5 lump a few people have had trouble with when fitting a performance air filter - Engine light on.
Maybe this problem also manifests itself when the air filter is dirty or clogged. I wonder if a performance air filter would make the light come back on.

After Volvokid's car was sorted with a TB clean, I'd like to get my hands on one of these 2.4 cars with the light on and pull all the plumbing - off for a damn good poke about.

Glad you have some peace of mind now mate, let us know if the light comes back on.

possible mrp, but i would have thought that if this was the case then it would not be possible to map these cars, as in theory you would have the same problem as a high flow filter- the maf sensor going above/ out of it's reading range when you increase the air flow with higher boost - normally there is loads of leeway.

the only car i know this can be aproblem on, is an early t4 because if you go above a certain boost/hp (and its loads!) then they fit a 2001> t4 maf because it has a higher capability.

[M-R-P]

possible mrp, but i would have thought that if this was the case then it would not be possible to map these cars, as in theory you would have the same problem as a high flow filter- the maf sensor going above/ out of it's reading range when you increase the air flow with higher boost - normally there is loads of leeway.

the only car i know this can be aproblem on, is an early t4 because if you go above a certain boost/hp (and its loads!) then they fit a 2001> t4 maf because it has a higher capability.

I'm wondering if these engines (ME9 iirc) are more sensitive to things like grubby throttle body, boost/vac leaks or tired maf than older cars, hence me wanting to get my hands on one with the light on and see if pulling it all apart, cleaning it and putting it back, makes any difference.

A remap would change the tolerances for fuel, air rates though wouldn't it?

[mikey32shaw]

My lights back on so if you want to just clean all mine up for me for the fun of it and out of the goodness of your heart ill pop it round ;-)

[partsforvolvos.com]

a remp does change the allowed values, as if the engine senses any value goes over the preset limit it restricts preformance by compensating other items or at worst goes into limp home mode.

this is partly why a mbc wont work on some later engine types

[silverhorse]

My lights back on so if you want to just clean all mine up for me for the fun of it and out of the goodness of your heart ill pop it round ;-)
Have you got a message as well as the light? I had Engine Management Service Required message. I read the codes and got ECM 120D Air Mass Signal too low and

ECM 121B Mass Air Flow flow too low

Possilble weak MAF. Could not cope with extra airflow from performance filter? I am still investigating.............