rocko

hey guys..i have an 01 430..car still shakes at idle..right now i have 52,250 on it and i was wondering if i could change the spark plugs on this to a BOSCH Super 4Platinum..hehe (16 of 'em)..do you think it'll improve the overall feel of the car at WOT and cure the shaking?(new engine mounts,new maf and new spark plug wires were installed by the dealer already) Lastly, how hard is this to do? Thanks in advance..Rocko

str8ridin

Have you changed your harmonic balancer? It's been recalled on several Mercedes and is the cause for some shakey idle....

TresX

Always use OEM plugs. Beru or Bosch (Copper)

rocko

ASC told me that my car was not part of the recall and that the harmonic balancer was updated before the car even made it to the showroom 4years ago..lol...so you think the super4's are not a good choice? as much as possible i dont want to be doing the "gapping" of the spark plug..lol..thanks again..rocko

DCarrera

Interesting post on the harmonic ballencer recall. I have a slightly shaky idle on my '99. I'm about to toss in some plugs (Bosch Platinum). The owners manual lists a Bosch PN that looks like it's a platinum plug.... but I did see on owner's post about pulling the plugs and they looked like standard coppers.

I guess I just need to pull one and know for sure.

I'll run a search on the harmonic balancer question.... this is the first time I've heard of that as a possible problem.

deyainrdy4ds

really? i thought ive seen a lot of member on here using aftermarket platinum plugs?

DCarrera

Just pulled the first plug. It's a Bosch Platinum (circa 1999), with the exact same PN as the owner's manual lists. Can't find my anti-sieze or I'd be well on my way to changing them out with some Platinum 2's that the local parts monkey looked up by application. Dimensionally they are the same. Should work fine.

BTW.. this page at About.com has the same PN's that my owner's manual lists, and matches the Bosch plug I just extracted from the motor. I guess I should take some pictures!

PAGE (about.com): http://autorepair.about.com/library/faqs/bl925f.htm

MarcusF

Way back when, we used to index sparkplugs. When you index a sparkplug, you’re positioning the gap to make the best flame front. With the M113’s dual plug ignition, and the plugs on the sides, it would appear that you’d want that gap facing inward. Except plus 4 plugs now have four ground electrodes. Not only does that make indexing an impossibility, it’s adding three additional flame front impediments. I’d never use a +4. Lastly, Hersh is right, OEM was platinum.

DCarrera

Precisely why I am not *thrilled* at the prospect of using the 2's but were also the minimal recommendation from Bosch, and I don't really trust NGK / Champion nor Autolight.... so... what are my options? I've run many a google and spark plug search and I've not found anyone selling the real factory single electrode F 8 DPER. I hope I do not regret the Platinum 2's although.. they are all still uninstalled... maybe I should opt for a another manufacture's single plat?