When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I checked the engine through the Camshaft Position Sensor and it all lines up.
Here's the issue; the car idles rough and throws the following codes:
Code Text
0629 Misfiring (P0300)
0645 Misfiring of cylinder 6 : Damages TWC (P0306)
0637 Misfiring of cylinder 4 : Damages TWC (P0304)
0653 Misfiring of cylinder 5 : Damages TWC (P0305)
Once I pull the MAF plug, the car idles nicely but throws MAF error codes (obviously).
I purchased a brand new MAF (Bosch) from amazon and the codes above noted above re-appear. Also, I tried a known good MAF and same errors reappear.
Alternatively, I
1) swapped the coils from Bank 1 to Bank 2;
2) re-gap'ed the spark plugs to 31mm (the plugs looked good, weren't fouled but all electrodes were pretty worn down and the gap on all plugs were approx. 65mm.
I think that the issue is MAF related, anybody have any ideas and / or experienced something similar?
I checked the engine through the Camshaft Position Sensor and it all lines up.
Here's the issue; the car idles rough and throws the following codes:
Code Text
0629 Misfiring (P0300)
0645 Misfiring of cylinder 6 : Damages TWC (P0306)
0637 Misfiring of cylinder 4 : Damages TWC (P0304)
0653 Misfiring of cylinder 5 : Damages TWC (P0305)
Once I pull the MAF plug, the car idles nicely but throws MAF error codes (obviously).
I purchased a brand new MAF (Bosch) from amazon and the codes above noted above re-appear. Also, I tried a known good MAF and same errors reappear.
Alternatively, I
1) swapped the coils from Bank 1 to Bank 2;
2) re-gap'ed the spark plugs to 31mm (the plugs looked good, weren't fouled but all electrodes were pretty worn down and the gap on all plugs were approx. 65mm.
I think that the issue is MAF related, anybody have any ideas and / or experienced something similar?
Thanks in advance.
Those are not Mercedes codes. You need a scanner designed to interface with all the systems in your car and understand Mercedes codes,
edwin, when there are misfire codes on all cylinders on the same bank, it cannot be a MAF issue. A faulty MAF would store its own code and would affect both banks.
If the above codes are the only ones stored, possibilities are : vacuum leak at the Intake Manifold (Left side), fuel leak at left side fuel injectors, clogged CAT convertor on left side causing back pressure, faulty spark plug leads.
I suggest buying spark plugs for both banks, but only replace those on the left side and see what occurs.
If not, spray Brake Parts Cleaner along the left side seam of the intake and see if RPMs increase. Do the same for injectors.
If not, buy an Exhaust Back Pressure Gauge and remove the O2 sensor before the CAT and install the gauge in its place. Start eng. and at idle, check gauge reading. Any reading above ZERO indicates a blockage. Then do the same at 2,500 RPMs.
If the above codes are the only ones stored, possibilities are : vacuum leak at the Intake Manifold (Left side), fuel leak at left side fuel injectors, clogged CAT convertor on left side causing back pressure, faulty spark plug leads.
Thanks Maj. Dundee... would these still be possibilities if, with an unplugged MAF, the engine idles well and it reaches high RPMs without issues?
When I purchased the car, in addition to the codes mentioned above, it had the following Stored Codes (which have not reappeared):
Code Text
2091 The mixture in the right cylinder bank is too lean when idling.
2095 The misture in the left cylinder bank is too lean when idling.
1425 Wheel speed signal is implausible.
I'm going to perform the following in their order and report back my findings:
1.:
Originally Posted by Maj. Dundee
I suggest buying spark plugs for both banks, but only replace those on the left side and see what occurs.
2.:
Originally Posted by Maj. Dundee
spray Brake Parts Cleaner along the left side seam of the intake and see if RPMs increase.
3.:
Originally Posted by Maj. Dundee
Do the same for injectors.
4.:
Originally Posted by Maj. Dundee
buy an Exhaust Back Pressure Gauge and remove the O2 sensor before the CAT and install the gauge in its place. Start eng. and at idle, check gauge reading. Any reading above ZERO indicates a blockage. Then do the same at 2,500 RPMs.
I purchased the Exhaust Back Pressure Gauge and it will be delivered by Amazon on Monday.
Also, to confirm, the error codes were drawn from a Xentry / DAS.
How long have you been driving the vehicle after you first erase the codes?
Unfortunately, I drove the car less than 5km before parking it in my garage.
1.:
Originally Posted by Maj. Dundee
I suggest buying spark plugs for both banks, but only replace those on the left side and see what occurs.
My local auto parts store did not have the correct spark plugs but I swtiched the plugs on both banks and it gave the same errors after 3 minutes of the car running (from cold).
2.:
Originally Posted by Maj. Dundee
spray Brake Parts Cleaner along the left side seam of the intake and see if RPMs increase.
No increase in RPMs.
3.:
Originally Posted by Maj. Dundee
Do the same for injectors.
No increase in RPMs.
Thereafter, I turned off the engine and I once again unplugged the MAF. The car idled well and I decided to do a little spirited drive and the engine worked really well during the drive.
Regarding test #4, I'll receive the tester tomorrow but if you have any further ideas, please do share!
edwin, I'm running out of ideas but is this the MAF part number that you bought? Where did you buy it from and how much did you pay for it?
I didn't go by the Mercedes part number but, rather the number appearing on rockauto's site and on Amazon. I purchased it from Amazon for approx. $67.
Bosch part number is 0280218190. This is a picture of the box:
Originally Posted by Maj. Dundee
Have you checked all the gaskets and hoses near and around the MAF ?
To be honest, after the initial install of the new MAF, I re-installed the air box. I have not re-installed the air box the past few attempts at diagnosing the error.
I will run the exhaust back pressure test tonight but given that the engine runs fine with the MAF unplugged, I am inclined to think that this is not a clogged-cat scenario. Thoughts?
Could this be an issue with the O2 sensors, is there a way to test them?
I then proceeded to remove the air intake manifold and this is what I found:
The broken swirl flap is located on the side of bank 1.... I understand that this controls the "short runner", "long runner" for Bank 2, is this correct?
Think I found the culprit to my misfires?
Last edited by edwin.dario; Jun 6, 2018 at 10:30 PM.
Educated guess is that the pins are held in place by a small leaf spring, and you have to carefully use something like a needle or pin from the connection side to get the leaf spring down so you can gently pull it out, then insert in the same hole on the new connector. I would suggest you get instructions from the dealer, since they sold it to you. I found a data sheet but it's in German.
Careful look at the data sheet confirms it. The tabs are there, in the holes, outboard side of each hold. You have to gently push them in and then gently pull the wire out.
Careful look at the data sheet confirms it. The tabs are there, in the holes, outboard side of each hold. You have to gently push them in and then gently pull the wire out.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
