freefall

Rob - If the engine light ISN'T on, would that mean that the plugs are fine?
Also - Is it worth it to go to the auto store, pick up some high performance plugs and swap them out myself?

Vic55

All I know is modded turbo cars tend to burn plugs out faster so if a stock car has an issue expect plug concerns to come for sure on a modded one.

On my 997TT after about 15k miles the car would start to buck at higher speeds under load-- it was heavily modded so I went 1 step cooler in the plugs.

If you have a tune and do new plugs you will probably get your tune wiped out with any updates the dealer does. Im glad my guy is local to do a reflash.

Rob@vividracing

I spent half a day on the phone with denso, ngk and bosch. Its a bosch plug but I wanted a one step colder plug because of the tune etc.

In the end of it I want to just send one of the 3 a plug because I think it would be helpful to have a one step colder option (haven't done it yet)

Only option right now is a mb part #.

freefall

So will the car catch this and pop the engine light on before you start feeling it or will you feel it first?

Vic55

Ill bet you would feel it (idle issues) first...

Saeedg48

you'll for sure feel it first. then a few miles later you'll get a check engine light with misfire codes.

freefall

Two hours, literally, after my SA called me back and told me that he knows nothing about bad plugs my car starts rattling at idle and then the engine light came on.

I also have a very new tune so this is going to be interesting.....

Mr. Happy

My god...do you guys think I'm safe with mine that is a March 2012 built (to be delivered in May)? Should I check with the dealer to make sure?... although it seems that the dealers are not very aware of this issue.

rleepremier

Cancel it.

hyperion667

I think the dealers are basically clueless until the/a car gets there(to their store) you know?
I wouldn't have to many reservations about ordering; MB seems to know about the
problem, despite the information not having 'trickled' down to all the dealers yet, haha...

Mr. Happy

Thanks. Let's hope for the best.

freefall

***UPDATE****
It was the plugs....

It will be ready by lunch tomorrow. No big deal....

Ali_E55

i need recall number please.

Saeedg48

it's vin specific from what I understand it doesn't impact all cars. but yah a recall number would b nice

PTE

The spark Plugs in a DI (Direct Injection) Motor live in a very violent environment. They have a piezoelectric type of injector & a Fuel rail that has upward of 24,000 PSI fuel pressure . The gas spray is directed to the top of the piston. In the spray path or very close proximity is the Spark Plug.It has to be close to light off the fuel spray for the auto stop & start, This spray has some good effects & Bad effects. It will cool the top of the piston ( Can run higher compression) , but adds to cylinder wall wetting. Bad for ring wear & cylinder wall erosion. Needs special Ring coatings & Piston Ring Land coating. ( Which they have done) Very GOOD. Spark Plug is kept cool, by the spray. No Need to go to a colder S/P. but the very hi pressure fuel spray can Laser cut the the center insulator if the S/P is set to deep. I looked to see if there was a combustion chamber fuel deflector pin, Not There yet ! this is why they are running the motor in straight Homogeneous Mode. They will still need a cat to clean up the emissions. S/P Technology still lags behind combustion Technology. I also suspect they are using the Bosch S/P with the iridium coating on the center electrode & J strap'(S) with platinum pads glued in place , Thats bad the pads blow off the air gap which is critical opens up wide , Can you say MISFIRING! the pads need to be welded in place. MB has done some neat stuff here. to help curb the nagging issues. But You can expect to be part of the learning Curve. The stop N Go feature doesn't use the starter in after the motor is up to temp. their is a position sensor the looks for a piston that is just a hair pass TDC Compression. Sprays some fuel & spark it off with a multi sparks . Like a MSD ign. I'm thinking the combustion Chamber pressure has already started to bleed off. This give a weak push on that cylinder & a really poor flame path. Part of the reason for a Cat in The Exhaust. Multi sparks at the S/P leads to quick Tip & J Strap erosion. Platinum pads! on Iridium coated parts.

We have not even talked about the what the EGR & PVC systems can do to the back side of the intake valves, They will look like a Flocked Christmas tree with the deposits caked to them and No fuel in the intake air charge to keep them clean. Have fun , P/S I've been dicking with DI motors since 1990
Cheers _PTEngineering

Ali_E55

i drove 30k km with stock plugs without any problem,

the dealer replaced my plugs @ 30k km as major service.

even if my car came with the updated plugs, maybe dealer installed the older version when they did the service

the plugs for this car really look cheap quality

Saeedg48

now that i'm learning more about this issue it seems the "older and newer plugs" are the same. the only difference is the recall in the plugs because of the quality control. they were airline cracks in the ceramic glue or something.. this is what the dealer told me. i hear the plugs are a good brand and work wonders if they weren't the defective ones.

Ali_E55

don't believe what a dealer says

lets just say:

my engine will have to be taken out and apart because of plugs

will report tomorrow or after it after i get full details.

PM me if you are intrested to get my story

Saeedg48

thanks for the information! why are the stock ones defective or not working, do spark plugs with direct injection just not last?

Ali_E55

PLEASE SEE THIS


https://mbworld.org/forums/cls55-amg...lug-broke.html

Ali_E55

i have NGK part number for our cars if you are intrested but it is the same cold degree as stock , which is 7

ScottCLS55

Can you post the NGK number here?
I hate bosch plugs in general anyway.
Gonna order some ngks.

Rob@vividracing

Yeah i'm interested in the part number as i'm sure some others are.

Saeedg48

i remember in one of the threads you said you were going to type colder plugs; you won't be able to use colder plugs on this car because of the washer that's on the stock plugs. they need to be tightened to a specific degree, they're not like other plugs.. let us know what happens when you use colder plugs, doubt the car will like them to be honest

Ali_E55

the washer is in bronze color, which is copper i think

here is the part number for all three:

Stock: A0041596403

Bosch: 0242140521

NGK: SILZKR7A-S