SLS/R197/C197 AMG: Need help to diagnose 2012 SLS
#1
Newbie
Thread Starter
Need help to diagnose 2012 SLS
This vehicle had a lot of problems with wires. I found some wires chewed up by rodents.. You can imagine what came next.....
2012 SLS AMG M159.980 A/T
Frustrating and sad story short:
Vehicle have misfire on cyl #7 while idling. after 2300 or 3000 rpm all the faults goes away.
Spark plugs: REPLACED (8)
INJECTORS: REPLACED (8)
Coils : REPLACED (8)
No improvements or changes whatsoever...
After finding chewed wires and looking closely every single inch of the engine harness a new one was ordered out of the dealer.
Engine Harness: REPLACED
Looking at Lambda values while idling I found UPSTREAM LEFT SIDE o2 sensor not working. So I ordered a new one.
While replacing the old O2 sensor I found on left side that upstream was wrongly installed on DOWNSTREAM position. So I change positions and replaced the upstream 02s anyways..
Customer tell me that the ECU was replaced by dealer, so I run a follow up after ME replacement.
No big changes on the CYL #7 misfire.
After checking LIVE DATA - FAULT COUNTER cyl#7 shows misfires at idling engine speed, but revving above 2600 RPM all the faults counts goes to 0.
COMPRESSION TEST SHOWS NORMAL VALUES
So, I eliminate fails from Coils, Spark plugs, Injector, wire harness, 02S.
What else do you guys recommend to look at it?
Find attached 2 short videos. AFTER 02sensor replaced.
2012 SLS AMG M159.980 A/T
Frustrating and sad story short:
Vehicle have misfire on cyl #7 while idling. after 2300 or 3000 rpm all the faults goes away.
Spark plugs: REPLACED (8)
INJECTORS: REPLACED (8)
Coils : REPLACED (8)
No improvements or changes whatsoever...
After finding chewed wires and looking closely every single inch of the engine harness a new one was ordered out of the dealer.
Engine Harness: REPLACED
Looking at Lambda values while idling I found UPSTREAM LEFT SIDE o2 sensor not working. So I ordered a new one.
While replacing the old O2 sensor I found on left side that upstream was wrongly installed on DOWNSTREAM position. So I change positions and replaced the upstream 02s anyways..
Customer tell me that the ECU was replaced by dealer, so I run a follow up after ME replacement.
No big changes on the CYL #7 misfire.
After checking LIVE DATA - FAULT COUNTER cyl#7 shows misfires at idling engine speed, but revving above 2600 RPM all the faults counts goes to 0.
COMPRESSION TEST SHOWS NORMAL VALUES
So, I eliminate fails from Coils, Spark plugs, Injector, wire harness, 02S.
What else do you guys recommend to look at it?
Find attached 2 short videos. AFTER 02sensor replaced.
Last edited by AvechuchoAxel; 05-25-2020 at 08:55 PM.
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AvechuchoAxel (05-25-2020)
#6
Newbie
Thread Starter
on the 6th picture, where it shows cylinder #7 I can't figure out yet... It misfires badly while a clanking noise can be heard. When engine runs fine for a few seconds, the noise goes away..
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#8
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Thread Starter
Definitely is left side problem, but after all what was replaced still having issues on same bank, same cylinder. The only thing left is to aim to the M.E. even it was replaced by dealer. After a short phone conversation with them, they said that the programming was performed, BUT never tested because at the time the car was there for service, exhaust system wasn't installed.
I'll love to find somebody with extensive knowledge and time to run a diagnostic and check live data either way at my shop or via TEAMVIEWER..
Last edited by AvechuchoAxel; 05-28-2020 at 12:19 PM.
#12
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Thread Starter
This is the weirdest thing I've ever seen.
Looks like the problem is not the engine itself. apparently there is a problem with the DRIVESHAFT bearings. Yes.. I lift my left eyebrow too...
apparently the bearings are gone and because of that is making a knocking sound that the knock sensor picks up that and therefore is modifying the timing on the left bank.
I took the car to the dealer where 2 techs spend hours diagnosing it. I trust their knowledge as strange its sounds to me.
So, next action plan is try to get the whole TORQUE TUBE either way new or used if available.
Ill appreciate any comment or suggestions. Is there any other M.B vehicle share the same torque tube or bearings replacement?
Thanks!
Looks like the problem is not the engine itself. apparently there is a problem with the DRIVESHAFT bearings. Yes.. I lift my left eyebrow too...
apparently the bearings are gone and because of that is making a knocking sound that the knock sensor picks up that and therefore is modifying the timing on the left bank.
I took the car to the dealer where 2 techs spend hours diagnosing it. I trust their knowledge as strange its sounds to me.
So, next action plan is try to get the whole TORQUE TUBE either way new or used if available.
Ill appreciate any comment or suggestions. Is there any other M.B vehicle share the same torque tube or bearings replacement?
Thanks!
#13
This is the weirdest thing I've ever seen.
Looks like the problem is not the engine itself. apparently there is a problem with the DRIVESHAFT bearings. Yes.. I lift my left eyebrow too...
apparently the bearings are gone and because of that is making a knocking sound that the knock sensor picks up that and therefore is modifying the timing on the left bank.
I took the car to the dealer where 2 techs spend hours diagnosing it. I trust their knowledge as strange its sounds to me.
So, next action plan is try to get the whole TORQUE TUBE either way new or used if available.
Ill appreciate any comment or suggestions. Is there any other M.B vehicle share the same torque tube or bearings replacement?
Thanks!
Looks like the problem is not the engine itself. apparently there is a problem with the DRIVESHAFT bearings. Yes.. I lift my left eyebrow too...
apparently the bearings are gone and because of that is making a knocking sound that the knock sensor picks up that and therefore is modifying the timing on the left bank.
I took the car to the dealer where 2 techs spend hours diagnosing it. I trust their knowledge as strange its sounds to me.
So, next action plan is try to get the whole TORQUE TUBE either way new or used if available.
Ill appreciate any comment or suggestions. Is there any other M.B vehicle share the same torque tube or bearings replacement?
Thanks!
I'm sure its not the driveshaft.