A1EK
Active Member
- Joined
- Oct 3, 2008
- Messages
- 135
- Location
- Glasgow
- Car
- Mercedes SL 3.7L AMG Speedshift - (Past: CLK 230, 190E, W201, W203)
Hi guys.
I had to change the MAF about 3 weeks due to a blocked breather pipe that was causing oil contaminaction over the years and through constant cleaning it eventually died. I have now fixed the oil contamination and I bought a cheaper non genuine MAF from EuroCP first of all which to begin with was fine and the car ran great but I noticed the MPG was lower then I used to get. Unfortunately this MAF failed after 3 weeks and so I took it back to the store for a refund and this time paid the extra and got a genuine BOSCH MAF for about £160 with BOSCH printed on it !
However my MPG even with the BOSCH was lower compared to how the car was before the orginal MAF failed on me.
I used to get on the motorway anything up to 37 MPG and in town around 23-25 MPG. Now however the motorway MPG is at best 31MPG with the town being around the same as old at 23-25MPG.
Can anyone suggest why my motorway MPG has reduced? Does the ECU take time to learn the new MAF as its interesting how both the new MAF's I tried were lower MPG then before?
I had got a diagnostic done when the cheap MAF I bought failed on me so I could prove it was faulty to EuroCP and when I bought the BOSCH one I got the garage to clear any fault codes.
Thoughts:
Im not thinking its the fuel filter as its only been changed in the last year .
The spark plugs are denso irridium and i've had them for a about 3.5 years, but should be still good and its too much of a coincidence that they now start to get bad?
The air filter is K&N and I have recently cleaned this out and purposly not oiled it much.
Could a bad oxygen sensor give lower MPG?, could it be dirty as I drove the car without the MAF plugged in for a few days and the car was running rich and should it be cleaned?
Was getting 37MPG on my old MAF strangley high and perhaps this was a sign the car was running lean and the MAF was old and failing as it did seem to increase each year ?
Any advise appreciated.
Thanks
I had to change the MAF about 3 weeks due to a blocked breather pipe that was causing oil contaminaction over the years and through constant cleaning it eventually died. I have now fixed the oil contamination and I bought a cheaper non genuine MAF from EuroCP first of all which to begin with was fine and the car ran great but I noticed the MPG was lower then I used to get. Unfortunately this MAF failed after 3 weeks and so I took it back to the store for a refund and this time paid the extra and got a genuine BOSCH MAF for about £160 with BOSCH printed on it !
However my MPG even with the BOSCH was lower compared to how the car was before the orginal MAF failed on me.
I used to get on the motorway anything up to 37 MPG and in town around 23-25 MPG. Now however the motorway MPG is at best 31MPG with the town being around the same as old at 23-25MPG.
Can anyone suggest why my motorway MPG has reduced? Does the ECU take time to learn the new MAF as its interesting how both the new MAF's I tried were lower MPG then before?
I had got a diagnostic done when the cheap MAF I bought failed on me so I could prove it was faulty to EuroCP and when I bought the BOSCH one I got the garage to clear any fault codes.
Thoughts:
Im not thinking its the fuel filter as its only been changed in the last year .
The spark plugs are denso irridium and i've had them for a about 3.5 years, but should be still good and its too much of a coincidence that they now start to get bad?
The air filter is K&N and I have recently cleaned this out and purposly not oiled it much.
Could a bad oxygen sensor give lower MPG?, could it be dirty as I drove the car without the MAF plugged in for a few days and the car was running rich and should it be cleaned?
Was getting 37MPG on my old MAF strangley high and perhaps this was a sign the car was running lean and the MAF was old and failing as it did seem to increase each year ?
Any advise appreciated.
Thanks
