SL/R129: Random missfire.
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Joined: Aug 2005
Posts: 399
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Random missfire.
Guys 99 SL500. 138k miles
From time to time, under load I get a miss and a check engine light. I cant duplicate the problem at will.
Restart the car and all is well again.
First the code showed 5 and 7 cyl.I changed coils on that side,
Now it shows again 3,4,5,6,7. Even with new coil packs on 5,7 and new spark plugs all around.
No egg smell. Car pulls hard.
Spark plug wires? MAF?
Why cant the codes be more accurate.
Thanks
Changed plugs which were old, used Bosch FR8DPP33 part number is 7422.
From time to time, under load I get a miss and a check engine light. I cant duplicate the problem at will.
Restart the car and all is well again.
First the code showed 5 and 7 cyl.I changed coils on that side,
Now it shows again 3,4,5,6,7. Even with new coil packs on 5,7 and new spark plugs all around.
No egg smell. Car pulls hard.
Spark plug wires? MAF?
Why cant the codes be more accurate.
Thanks
Changed plugs which were old, used Bosch FR8DPP33 part number is 7422.
Out Of Control!!
Joined: Sep 2018
Posts: 14,651
Likes: 4,558
From: unbegrenzt
2017 GLE350 4MATIC
Guys 99 SL500. 138k miles
From time to time, under load I get a miss and a check engine light. I cant duplicate the problem at will.
Restart the car and all is well again.
First the code showed 5 and 7 cyl.I changed coils on that side,
Now it shows again 3,4,5,6,7. Even with new coil packs on 5,7 and new spark plugs all around.
No egg smell. Car pulls hard.
Spark plug wires? MAF?
Why cant the codes be more accurate.
Thanks
Changed plugs which were old, used Bosch FR8DPP33 part number is 7422.
From time to time, under load I get a miss and a check engine light. I cant duplicate the problem at will.
Restart the car and all is well again.
First the code showed 5 and 7 cyl.I changed coils on that side,
Now it shows again 3,4,5,6,7. Even with new coil packs on 5,7 and new spark plugs all around.
No egg smell. Car pulls hard.
Spark plug wires? MAF?
Why cant the codes be more accurate.
Thanks
Changed plugs which were old, used Bosch FR8DPP33 part number is 7422.
Also check grounds on the chassis (body sheet metal) and on the engine to be sure they are not loose or corroded.
