Air Mass Sensor
Discussion
I posted last week to the effect that my MK. 1 GT3 had developed a sort of misfire/hesitation at 4000 plus RPM.
Exeter OPC diagnosed a faulty Air Mass Sensor.
Technician Wayne ( top man ) fitted a replacement yesterday which has cured the problem.
The car is now so much more responsive , and I had not realised that over a period of time the overall performance had deteriorated to the extent that it had.
Worth bearing in mind if anyone experiences similar.
Exeter OPC diagnosed a faulty Air Mass Sensor.
Technician Wayne ( top man ) fitted a replacement yesterday which has cured the problem.
The car is now so much more responsive , and I had not realised that over a period of time the overall performance had deteriorated to the extent that it had.
Worth bearing in mind if anyone experiences similar.
Don't. From experience they will be better for a short time then go screwed again. I think when cleaned, the business part of the sensor loses some sort of protective coating.
Some engine tuner I spoke to said it often makes it worse and since a poor maf will result in lean running (which admitedly the ECU should sort out somewhat with the lambda sensor) which on something high revving might do some harm.
They're cheap enough so I'd recommend just going and buying one (or mine, lol).
SM
Some engine tuner I spoke to said it often makes it worse and since a poor maf will result in lean running (which admitedly the ECU should sort out somewhat with the lambda sensor) which on something high revving might do some harm.
They're cheap enough so I'd recommend just going and buying one (or mine, lol).
SM
runner911 said:
I posted last week to the effect that my MK. 1 GT3 had developed a sort of misfire/hesitation at 4000 plus RPM.
Exeter OPC diagnosed a faulty Air Mass Sensor.
Technician Wayne ( top man ) fitted a replacement yesterday which has cured the problem.
The car is now so much more responsive , and I had not realised that over a period of time the overall performance had deteriorated to the extent that it had.
Worth bearing in mind if anyone experiences similar.
....my gt2 has been doing this. I'm convinced it is the MAF but opc pluged it in and no fault code came up. I have an extended warranty which should cove the MAF but OPC won't cover it unless there is a fault code. Also they drove the car and reported it was running perfectly, thing is i doubt they drive many gt2's to know what normal feels like, the intermittent hesitation experience is just that, intermittent. How much are these to replace?Exeter OPC diagnosed a faulty Air Mass Sensor.
Technician Wayne ( top man ) fitted a replacement yesterday which has cured the problem.
The car is now so much more responsive , and I had not realised that over a period of time the overall performance had deteriorated to the extent that it had.
Worth bearing in mind if anyone experiences similar.
If you have the same part number as mine, I'll let you borrow it to see if it's that.
I had a mountain of trouble with BMW about this with my M5 but in the end I presented them with an oscilloscope trace from a Bosch bloke who knew his onions and could test it. Get to a rolling road and see how much power it makes.
The M5 had an OBD function accessible by voodoo with the pushbuttons on the dash showing how many litres/hour of petrol it was pouring in at the redline. A dirty maf will reduce the fuel going in (went from ~130l/h to 100l/h),
They changed them in the end and it totally transformed the car. No fault ever showed up. Perhaps you could disconnect yours (harmless -- the car will default to safe values), and run it about. They say a knackered MAF is worse than no MAF so things should improve. In any case you'll get a fault logged and hey presto! they'll change it...
Where are you? Maybe we could swap MAFs by way of experiment or you could borrow my known good turbo one if they're the same.
PM me if you like.
Cheers
SM
I had a mountain of trouble with BMW about this with my M5 but in the end I presented them with an oscilloscope trace from a Bosch bloke who knew his onions and could test it. Get to a rolling road and see how much power it makes.
The M5 had an OBD function accessible by voodoo with the pushbuttons on the dash showing how many litres/hour of petrol it was pouring in at the redline. A dirty maf will reduce the fuel going in (went from ~130l/h to 100l/h),
They changed them in the end and it totally transformed the car. No fault ever showed up. Perhaps you could disconnect yours (harmless -- the car will default to safe values), and run it about. They say a knackered MAF is worse than no MAF so things should improve. In any case you'll get a fault logged and hey presto! they'll change it...
Where are you? Maybe we could swap MAFs by way of experiment or you could borrow my known good turbo one if they're the same.
PM me if you like.
Cheers
SM
I guess you have your experience, I have mine. Renntech and Rennlist also have differing opinions. I cleaned mine 3000 miles ago and it's been great ever since ...
supermono said:
Don't. From experience they will be better for a short time then go screwed again. I think when cleaned, the business part of the sensor loses some sort of protective coating.
Some engine tuner I spoke to said it often makes it worse and since a poor maf will result in lean running (which admitedly the ECU should sort out somewhat with the lambda sensor) which on something high revving might do some harm.
They're cheap enough so I'd recommend just going and buying one (or mine, lol).
SM
Some engine tuner I spoke to said it often makes it worse and since a poor maf will result in lean running (which admitedly the ECU should sort out somewhat with the lambda sensor) which on something high revving might do some harm.
They're cheap enough so I'd recommend just going and buying one (or mine, lol).
SM
Maybe I shouldn't have cleaned the one on my M3 with a sanding disk, lol. Didn't really but I did find the improvements short lived, and the bosch guy certainly said there's a danger.
Probably well worth a clean then by the sound of it. Are you sure it was dirty? Maybe taking it out you sorted out a poor connection or something? Who knows?
SM
Probably well worth a clean then by the sound of it. Are you sure it was dirty? Maybe taking it out you sorted out a poor connection or something? Who knows?
SM
supermono said:
Maybe I shouldn't have cleaned the one on my M3 with a sanding disk, lol. Didn't really but I did find the improvements short lived, and the bosch guy certainly said there's a danger.
Probably well worth a clean then by the sound of it. Are you sure it was dirty? Maybe taking it out you sorted out a poor connection or something? Who knows?
SM
It really depends what you clean it with! I'm sure cold airflow from the dirty end of a car combined with a electrically hot film component could benefit from a clean with a suitable electronics cleaner regularly Probably well worth a clean then by the sound of it. Are you sure it was dirty? Maybe taking it out you sorted out a poor connection or something? Who knows?
SM
supermono said:
If you have the same part number as mine, I'll let you borrow it to see if it's that.
I had a mountain of trouble with BMW about this with my M5 but in the end I presented them with an oscilloscope trace from a Bosch bloke who knew his onions and could test it. Get to a rolling road and see how much power it makes.
The M5 had an OBD function accessible by voodoo with the pushbuttons on the dash showing how many litres/hour of petrol it was pouring in at the redline. A dirty maf will reduce the fuel going in (went from ~130l/h to 100l/h),
They changed them in the end and it totally transformed the car. No fault ever showed up. Perhaps you could disconnect yours (harmless -- the car will default to safe values), and run it about. They say a knackered MAF is worse than no MAF so things should improve. In any case you'll get a fault logged and hey presto! they'll change it...
Where are you? Maybe we could swap MAFs by way of experiment or you could borrow my known good turbo one if they're the same.
PM me if you like.
Cheers
SM
That is very kind of you. I love that about PH, people are just so damn nice and helpful. Are the MAF'S easy to change as a DIY? Is there a picture demonstration of how to do it? I had a mountain of trouble with BMW about this with my M5 but in the end I presented them with an oscilloscope trace from a Bosch bloke who knew his onions and could test it. Get to a rolling road and see how much power it makes.
The M5 had an OBD function accessible by voodoo with the pushbuttons on the dash showing how many litres/hour of petrol it was pouring in at the redline. A dirty maf will reduce the fuel going in (went from ~130l/h to 100l/h),
They changed them in the end and it totally transformed the car. No fault ever showed up. Perhaps you could disconnect yours (harmless -- the car will default to safe values), and run it about. They say a knackered MAF is worse than no MAF so things should improve. In any case you'll get a fault logged and hey presto! they'll change it...
Where are you? Maybe we could swap MAFs by way of experiment or you could borrow my known good turbo one if they're the same.
PM me if you like.
Cheers
SM
WN
...BTW i'm in Nottingham
MAF couldnt be easier to change...certainly on Carreras and GT3's its visible, not sure on the TT/GT2's. Did mine on the C2 not long after buying it, usual hesitation problem, but none of the Porsche diagnostics picks it up....which I found out only after an Indy had "guessed" at it and replaced 2 x Lamda's for me at significant cost!
Changed the MAF myself, just a single torx bolt, iirc....literally a 5min job, if that. Eurocarparts should be able to supply; somebody posted here not so long back, saying Bosch have only ever made a handful of different MAF's for practically the WW population of injected engines! (dont quote me on that!)
Changed the MAF myself, just a single torx bolt, iirc....literally a 5min job, if that. Eurocarparts should be able to supply; somebody posted here not so long back, saying Bosch have only ever made a handful of different MAF's for practically the WW population of injected engines! (dont quote me on that!)
Surely the OPC should at least try and swop it if it i such an easy job! Last time i took it in they reset the ecu, not made any difference other than it now returns 26-27mpg on a motorway run where as it was only ever 23-24...could this suggest it is running lean. If so would the OPC take this onboard as another symptom?
In reply to Welshnobby , the total cost of replacement of the sensor was £335, a lot for the component , but I must say that the improvement in performance makes the cost worth it.
The technician also had to reset the ECU using a laptop in order to delete the fault code which was showing.
The technician also had to reset the ECU using a laptop in order to delete the fault code which was showing.
You need a security torx tool, not sure what size but widely available. I'm sure you'll be able to find a picture but basically it's the only thing on the inlet tract that's secured by two torx bolts, black with a loom connection.
Very easily accessible on the turbo, not actually looked on the GT2 but it's bound to be identical.
Here's one here. Looks like they're a single part number according to this site.
http://cgi.ebay.com/ebaymotors/Porsche-911-996-c4-...
Anyhoo, let me know what you want to do. I'll happily post you the thing to try and return. Can't remember what I paid for my new one but Porsche will tell you -- don't pay them to fit it it's honestly five minutes just don't drop the bolts
SM
Very easily accessible on the turbo, not actually looked on the GT2 but it's bound to be identical.
Here's one here. Looks like they're a single part number according to this site.
http://cgi.ebay.com/ebaymotors/Porsche-911-996-c4-...
Anyhoo, let me know what you want to do. I'll happily post you the thing to try and return. Can't remember what I paid for my new one but Porsche will tell you -- don't pay them to fit it it's honestly five minutes just don't drop the bolts
SM
The money doesn't bother me to much as it isn't costing the earth. it is that the OPC won't even acknowledge that there is a problem and as it is a warranty part they should cover it if it is faulty. Can they take it out and test it, or can i get it replaced then send it to Bosch to test it and claim back from OPC?
Re above, when the technician plugged in his laptop to my GT3 a # sign appeared against a letter D on the display which apparently quite clearly indicates that there is a problem somewhere with the air intake.
The only thing that can really go wrong in this area is the sensor.
Any computer is only as good as the person operating it. I would have thought that an OPC technician would have been able to operate a laptop plugged into your car welshnobby , but if you have doubts why not take it to another OPC and get it checked ?
I suspect that if you remove the component yourself to send it away to have it checked you will invalidate your warranty in respect of that item.
The only thing that can really go wrong in this area is the sensor.
Any computer is only as good as the person operating it. I would have thought that an OPC technician would have been able to operate a laptop plugged into your car welshnobby , but if you have doubts why not take it to another OPC and get it checked ?
I suspect that if you remove the component yourself to send it away to have it checked you will invalidate your warranty in respect of that item.
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