MPOW33R

Im having rough idle issues that started creeping up on me and progressively getting worse. Nothing HORRIBLE just not as smooth as a 60k car should be.

Some suggested spark plugs?

I read on a few spark plug threads that the factory recommended

BOSCH are not they way the used to be and to go with NGK

Can anyone elaborate on my rough idle problem?

Also if it is the sparks, whats the best plugs for the e500

Thanks

otto6457

Rough idle could be caused by several issues. Replacing the plugs is a good place to start if they haven't been replaced in 60K miles.

The injectors might be getting a little "spikey" due to carbon build up which is also relatively common. Especially if fuel quality is inconsistent. A fuel additive such as BG 44K or Chevron Techron can help clean the injectors and help with the overall buildup of carbon deposits on valve faces, combustion chambers, and intake runners.

Like I said, there are many things that can contribute to a rough idle, but starting with these two simple repairs (plugs and fuel additive) could be all you need and both are easy enough and relatively cheap.

And I no longer use Bosch plugs and prefer NGK over the Bosch. However, I prefer Denso over all other plugs. I believe the Denso Double Platinum plug for your Mercedes is part#6405-05051962. The Denso Iridium plugs (#6405-05051973) are VERY good also. They are a bit pricey but they are exceptional.

homeofstone

I use NGK iridium plugs. that said a rough idle caused by plugs should also cause rough running on highway. Have it put on a diagnostic machine before you through money at it from guessing.

desired_speeds

when you do the plugs, do the wires also. Its typically the wires that cause the roughness rather than the plugs themselves.

MPOW33R

Thanks all, I also was informed that it can be a transmission mount - apparently its a common problem with the e500s

My local dealer does free inspections. Im going to take it Thurs. Ill update the post with what they come up with -

Thanks for chiming in

Flash Gordon

Possible motor mount, not transmission.