98 e320 Spark Plugs
 

How difficult is it to replace the plugs on a 98 e 320? My mechanic talks like it's about a three hour job. I realize there's twelve of them, but other than removing some of the air cleaner components, what else has to come off to get to all of the plugs? Do you have to be under the car (car on a lift) to get to some of the ones in the rear of the motor? I've also heard prices from $75 to $150 for the plugs themselves. That's a pretty wide range? How much are they and are they only available at the MB Dealer or can I go to a parts store and get them? Lastly, on the plugs, what is the torque setting? Thanks

I previously asked about installing a sunroof cable for this car without removing the headliner. Anybody know if this is possible? Thanks

Dave M

This answers your question about availability & prices for sparkplugs.
http://catalog.eautopartscatalog.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=1FU1CD1PL1J80QTB0R&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1998&product=F1000-116348&application=000346404
Can't help you much with the rest.

Dave,

If your plugs are original they will be a ***** to get out. Mercedes recommends 4 years or 100K miles which ever comes first.

I replace my plugs a few years ago and the job is fairly easy but plan for a several hour job. The boots may seem like they are welded on to the plugs. I used a twisting motion to break them loose, do not pull on the wire or it will seperate from the boot and you will end up replacing wires.

I used anti-seeze compond on the new threads and dielectric greese in the boots to allow the plugs to come out easier the next time they need changing.

When I replace my plugs I purchased them from FastLane and it cost me $75. I would stick with the factory recommended Bosch plugs.

Do a search for more info.

e320 spark plugs
 

Thanks for the info. Is there a danger of breaking a plug off in the head? I've had this happen before on another car. Do you think it would be better for the motor to be warm? Does Bosch Platinum+4 sound like the right plug? It looks like there are 2 NGKs and 2 Boschs from which to choose.

Dave

I used the Bosch F8DPP332 plugs, call or e-mail Phil in parts if you have any questions.

You will need to take your time and ease each plug out. To avoid breaking the plug try to keep the socket perpendicular to the plug, do not apply up, down or sideways force.

I prefer to do the plugs with the engine cold to avoid stripping the threads.

Engine temp won't be a big deal, I'd rather do it cold to avoid burned hands.
Never seen one snap on a 112, always a first time I guess.
I'd stick with the Bosch plugs, find out the current recommendation from MB, then shop them out.
I'd avoid the other brands. MB originally offered Bosch, Beru, and Champion numbers, I think they decided to just go Bosch.
It'll run alot better with new plugs.
What's wrong with the sunroof?

Gilly

e320 spark plugs/sunroof
 

Thanks Gilly,

I would rather do the plug change on a cold engine, too, for the same reason.
But, the thought of breaking a plug off on this engine is kinda scary.

I posted a sunroof query awhile back with no response. I've removed the roof, greased the cables with the proper grease, replaced the cable cover plates with the new "2 hole" plates, but the cable still escapes the track when the roof is retracted. I think the cable was weakened from all the kinking that occured prior to realizing that I needed to service the sunroof. Anyway, I think I need to replace the cable itself. My question then and now is whether or not I would need to remove the headliner to replace the sunroof cable or whether it was accessable from the top with the sunroof removed.

Dave

I believe the headliner stays in place, the dome lamp is just removed and the sunroof motor, kind of stretching the ol' memory bank here, but between removing the motor and those access plates you replaced, I think that gets the job done. Yeah I've seen this too and I believe that replacing the cables will fix it up, make sure to lube the track to keep this from happening again. The cables get weak from popping out of the guide, then it has a "memory" to do this again, will pop out again without a problem.
I don't think warming the engine is any real great benefit to keep the plugs from breaking. If it's more comfortable to do the job you can be slower and more careful, there is probably an advantage to that which will keep you from busting plugs. Main problem for DIY is to keep from breaking the plug wire ends, MB has a wrench they advise to use for prying off the plug wires, research that tool.

Gilly