Mercedes-Benz Forum banner

1 - 6 of 6 Posts

·
Registered
1997 E320
Joined
·
5 Posts
Discussion Starter #1 (Edited)
1997 E320 error code p0303 cylinder 3 misfire now P0302 cyl 2 miss fire

I just replaced the spark plugs, and test drove the car and it is still running rough and the check engine light and engine electronics are on.
What would be the next step? When I was at my local O'reilly's auto parts store to buy the plugs, the wires were special order for $120 to $200 dollars.
I do not know if this includes the 3 modules that are on top of 3 of the plug leads or not.
The car has 134000 miles, bought from my brother-in-law. He had bought it at 70000 miles and never tuned it up so I do not know if all are original.
Has anyone else had this issue? Or any thoughts on this would be appreciated.
Thanks Jeff
I just replaced plugs again Bosch copper standard electrode, Karlyn plug connector (3), coil to plug and Bosch ignition coil(replaced the one for cylinder 3) from AutohausAZ.
Problem is that the car is still running rough, I erased the codes but now I am getting P0302 cylinder 2 miss fire.
I am planning to order the wire set and the other 2 coils.
With this said are there any other ignition parts to check or will this take care of my issue?
 

·
Registered
1997 E320, 1997 S320
Joined
·
2,946 Posts
you were way due for a tune up, considering your engine needs new plugs every 30k miles. in your engine i would use only copper non-resistor plugs (bosch f8dc4, ngk BP6EFS, denso T20EP-U, or equivalent in other brands). also you need to change the 3 black rubber connectors from coil to plug (cylinders 2, 4, 6), they cost around $6 Your Parts Search Returned 2 Part(s) you could also move the coils around to see if the misfire moves, but i strongly recommend using the correct plugs and replacing the 3 connectors first.

by the way oem bosch wires are only $60 from autohaus, so don't waste money on o;reillys wires.
 

·
Registered
1997 E320
Joined
·
5 Posts
Discussion Starter #3
Thanks

you were way due for a tune up, considering your engine needs new plugs every 30k miles. in your engine i would use only copper non-resistor plugs (bosch f8dc4, ngk BP6EFS, denso T20EP-U, or equivalent in other brands). also you need to change the 3 black rubber connectors from coil to plug (cylinders 2, 4, 6), they cost around $6 Your Parts Search Returned 2 Part(s) you could also move the coils around to see if the misfire moves, but i strongly recommend using the correct plugs and replacing the 3 connectors first.

by the way oem bosch wires are only $60 from autohaus, so don't waste money on o;reillys wires.
Thank you for the info, I'm going to order the connectors and correct plugs
right now from autohausaz.
Jeff
 

·
Registered
'01-E320 & 02-ST2
Joined
·
31,631 Posts
Welcome, Jeff. Sounds like you're on the right track, connectors are a typical replacement item for the M104.

Just my two cents, but there's not a lot of OEM quality parts available at neighborhood parts stores for these cars. Most folks that DIY here use autohausaz.com; there are a few others but that seems to be the most popular. Good prices, fast service, quality parts and free shipping if you drop $50.

Please click user cp and add your vehicle and location to your profile; it's useful information.
 
1 - 6 of 6 Posts
Top