[tomtuttle]

Iridium's post was VERY helpful to me. I changed my 280 plugs using Bosch YR7MPP33 about 20k miles ago, and no troubles. It was a VERY easy job compared to transverse-mounted V6's I've worked on.

Edit - forgot to mention... While the plugs are rated for a very long life (100k miles or 5 years, I believe), my independent mechanic encouraged me to just do them well before 100k miles, as if you wait "too long", you may have very significant difficulty removing them.

 

[gdb069]

I questioned NGK about long life spark plugs getting corroded onto the head if left unchecked for a long time and the need for anti-seize. Of course they recommend follow the manufacturers recommendations for spark plug change. We discussed the issue that some of my vehicles are in storage for a long time and may never get to the manufacturers recommeded spark plug change ie. I have a 1969 Triumph Bonneville where the recommeded spark plug change is 12,000 miles but that bike will never get that much mileage! NGK added:

"NGK Spark Plugs are manufactured with a special trivalent Zinc-chromate shell plating that is designed to prevent both corrosion and seizure to the cylinder head; Thus eliminating the need for any thread compounds or lubricants."

If anyone has found any corrosion or difficulty in removing these plugs please let me know as I am using them in several vehicles that are stored for a long time and not used often. My SLK plugs will be used until 2015 at about 80,000 miles so 10 years of use and then replaced. I did check in 2010 at 50,000 miles and the plugs were perfect.

In my older motorcycles and cars I used anti-seize but stopped using it when the newer spark plug material became available and am concerned if there has been any seizing of the plug. (I do keep one bike completely stock with its original Champion N3 plug from 1969 that has antiseize compound and I replace the compound every few years)

Gordon

PS Hi Tom I know you love your indy and no slight intended but it may be interesting to read other experiences as sometimes the indys are working on pretty old junk or may be slightly biased.

 

[tomtuttle]

No worries, Gordon. We all benefit from more data. I replaced my plugs at about 60k miles (based on TIME rather than mileage). I had no trouble getting them out, and they looked just fine. I figured if I was going to loosen them, I might as well change them, too. Made me feel better. I'm sure that the risk of seizing is probably related to all kinds of factors.

Mostly, I just wanted to encourage folks (at least the 280 owners) to try this DIY.

Cheers!

 

[Fran]

Thanks Iridium for the great write-up. I just replaced the sparks on my 280 last night without problem. The resistance you get when pulling the coil packs out just takes patience and constancy. Resist the urge to twist or "wiggle" it around too much. What's causing the resistance is the vacuum created by the rubber sleeve over the spark plug neck. Think of it like opening a wine bottle, slow and steady.

 

[fastdawg1]

The instructions were dead on, easiest spark plug change ever. The plugs I took out were very clean for 62k, very even burning, very little deposits it any. No one should ever pay to have this done! The plugs i took out were showing a gap of around .037, put the new ones in at .031. Started up smooth an flawless. Thanks for the DIY.

 

[bwessels]

My 2005 SLK 350 just turned 63,000 mi and has original plugs, in the past month I have noticed when idling a cylinder must be misfiring it does it about once a minute I get the chug otherwise runs fine. I figure its time for new plugs anyhow but apprehensive about the procedure until I found this write up. I have all the tools including a torque wrench so gonna go for it. I just orders a 6-pack of the
Bosch plugs on Amazon for $50. There were a couple of reviews of people putting them in SLK 350 one was a 2005 too, all said no problems and improved performance even. Many said they did not adjust the gap, think its set at .035. Anybody know what
the recommended gap is exactly? Any other tips appreciated. I will report back my experience. Thank you again for this great
forum and this well written tutorial by Iridium.

 

[REB_TN_06]

Like the dawg said, this job is easy for the V6. I did mine at 50,000 and need to do it again now that I'm approaching 100k.

-Take your time.
-Once you pull the air cleaner it's all right there in front of you.
-Do the coils one at a time.
-Make sure to keep any foreign material out of the plug area.
-When torquing the new plugs take care to keep the socket extension aligned with the plug. You don't want to get out of line and crack the top of the plug.

You will gain quite an admiration about how these cars are designed and built.

Best Wishes



Sent from AutoGuide.com Free App

 

[bwessels]

Update slight change of plans!

OK well I was reading quite a bit about various fuel additives because I have NEVER used any always considered them a waste and potentially harmful.
But after reading here, on the MB user site and numerous reviews discovered there is a big following of Techron and BG 44K. So I decided to grab some of the Techron right at Walmart for $5. Poured it in with 3/4 tank used a small long neck funnel to open the flap to make sure it got in there. Went for a 30 min drive with lots of turns to shake it up! The next day I drove @ hour drive kept rpms @3000. Pulled over to let it idle in D and waited and waited and waited, and maybe had one small miss and chug. Coinkidink? Today drove another hour or so down to 1/3 tank pulled over and idled, waited for 5 minutes, nothing, also seems overall smoother car doesn't vibrate as much when idling. Went back out and decided to give it a real work out on expressway and back roads. No question the car was performing better when accelerating and no more hesitation when idling whatsoever:smile:
Anyway just so its on the record I am now a believer and will include this as part of my routine care. I read run a tank or two of it through every oil change. As far as the plugs go I am still going to do them but soon I will be storing my SLK for winter so now that its running beautifully I am going to postpone the plug change until I bring it out in Springtime!
And back to grab a few bottles of Techron, going to try one in my Nissan Pathfinder. My Audi has FSI direct fuel injection so I need to research if it may also be used in it and any reports of results if it can be.


Thanks again everyone for your help and I am curious if any of you use either the Techron or BG 44K and your experience with it.

 

[bwessels]

New Plugs In !

So its a rainy, cold day out and I was bored and since new plugs arrived kinda anxious to see if they made any difference. Took me a little over an hour but I am a very cautious amateur mechanic but I encountered no problems at all.
Hand threaded in and snugged with regular ratchet, then torqued to 17 ft/lb (or 23 nm) I found wire leads to the coil were plenty long, no bending the boots here??? Used an angle Torx, looks like an allen wrench and worked great to break the initial hold of the coil screws. Gaps on the old plugs were all >.42 and some carbon build up but nothing that looked out of the normal from what I know. Anyway fired it up and now runs like new, interesting how little things that gradually and slowly happen you don't notice but when I started getting those misses you could here and feel when idling I knew my baby was not as perky as usual! I used the Bosch plugs mentioned here and I will report back after I've had them in a while but off the bat they seem fine.
Thanks again for a great DIY write up that saved me $400-500 :grin:

 

[bdhanga]

Another real nice and easy DIY that was simply fun to do, and could not have gone smoother. Thanks Iridium

 

[Iridium]

UPDATE: I just did the plugs on my 2006 SLK280 using this (my own) DIY and again it was straightforward. The car has 52k miles at this point.

The coil pack wires on this car are longer than they were on my '05 SLK350 so there was no need to bend the tubes on the coils to get them in and out, like a few other people have said.

Weird thing, though. Three of the plugs I took out today were NGK brand plugs with the Mercedes logo on them (model PLKR6A) and the other three were Bosch plugs (model Y7MPP33). It looks like someone replaced the spark plugs on only one side of the engine. I don't know why anyone would do that.

The replacement Bosch plugs showed considerably less electrode wear (electrodes were longer) but that's probably because they were newer.

The previous owner took the car to the dealer for all services. Best I can figure is that she got ripped off at some point for a "spark plug change" that was only half the job.

 

[Rush2112]

...

The previous owner took the car to the dealer for all services. Best I can figure is that she got ripped off at some point for a "spark plug change" that was only half the job.

Thanks for the write up. I was looking for info on torque and SP gap and the kind folks here were able to provide all the info...

Don't be too hard on the mechanic... it may have been an honest mistake rather than intentional fraud. I was a mechanic before going to college (long story, didn't take the conventional education path) and I can say that after years of working on cars six days a week, 6 - 8 - 10 cars a day, mistakes and oversight can occur.

Often, there is a parts person ordering and filling your service request and you may get a stack of parts at your work station or pick-up counter. You go about your tune-up, brake job, whatever and if they were short three plugs and they told you the parts were coming in after lunch it may have got overlooked when the tech came back and buttoned up the car.

The previous owner paid for a service and didn't receive what they paid for and that's not fair... all I'm saying is may not have been an intentional "rip off".

 

[AndrewHart]

Excellent DIY! I can't thank Iridium enough. I just did my spark plug change last weekend and it went super smooth. After almost 90k miles I thought my plugs would be a lot worse but they weren't nearly as bad. I went with the Bosch ones here: https://www.amazon.com/gp/product/B0069SF8CM/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1