Hello all,

For the last 6 months I've had this issue with my S500. Smoke seems to come from engine bay after coming to a stop/idle after driving at highway speeds. No sign or smell of the smoke while driving at highway speeds. I've also drove the car around the city, no more than 50 mph (seems to be the threshold for the smoke to appear) for over an hour at a time running errands with no sign of smoke or smell. But the second I do a pull to the next stoplight and go over 50 mph, smoke appears when I idle.

For context, this was my grandads car, he got it brand new and it sat it a garage for quite a few years up until I inherited 2 years ago. It has 150K miles on it and I've put a good amount of money and time into reviving the car w routine maintance. Fixed door actuators, various pumps and hoses, Replaced the whole A/C system, new struts, alternator/belt, new battery, brake rotors/pads, lowering links, amongst other visual interior and exterior upgrades/refurbishments.

Relating to this specific smoking issue, as I said I've had it for 6 months or so. Randomly happened one day, no codes. Still no codes come up for it, even as other issues show face. I had been meaning to replace/service most components of the M113 engine in my S500 eventually so I just started taking her apart and fixing things. I've done all these fixes over the course of the last 6 months. At first I thought it could be valve gaskets/spark plugs, potentially a leak because i've been having a misfiring issue (unrelated). Didn't see any sign of a leak, but still replaced valve gaskets and spark plugs. Had my local Mercedes mechanic replace catalytic converts (misfiring issue from above). This month I was having starter issues with the car and got the code for issues w crankshaft shaft position sensor, so I replaced that. I've also replaced secondary air pump, and the solenoid. Lastly, I've replaced the EGR valve w/ a whole new kit (this is what I assumed the problem was after fixing all I've listed before but it wasn't). All these replacement parts are new OEM parts, mostly Bosch from fcpeuro.

I've been following forums on this site for years as i've always owned Mercedes and this place is great reference for finding issues others have had in the past. Over the last 6 months, I've meticulously looked through different threads and other resources pertaining to the m113 or w220 to figure out what this issue could be. Unfortunately I've been unsuccessful in my efforts. I'm not the most mechanically inclined but I figured it would have to be something related to EGR Valve (even tho I replaced it), the exhaust or intake manifold, or somewhere along the line of where the exhaust fumes flow after going through the EGR valve system. As I said before, the cats have been replaced and no sign of oil leaks. pls help

Attached are some pics of my ride. Been planning on wrapping her glossy black because the paint is fading. I'm also planning on upgrading the media components, I already bought an aftermarket bluetooth head unit, and I'm going to get a sub and amp. Also going to do a muffler delete and maybe cut the secondary cats so I can xpipe/dual tip the exhaust system. Also, I know the wheels are a bit crazy, I like it like that lol

Anyways, If you have any ideas, please hit me with them. I'm tired of having to drive below 50mph in this car, I want to be able to do a pull and come to a stop not in a a heap of smoke. Thanks in advance!

 

Love those rims those are the MRR rims. Most likely you have a small leak at your valve cover gaskets, a rear main seal and you’re seeing smoke from engine oil hitting the hot manifolds. It is very common for them to leak, and not cheap to fix.

 

are there any oil leaks when you park it

depends how much of this smoke enters cabin

 

MRR

 

No crazy leaks, will have to check tomorrow. I already ordered a valve cover gasket replacement

 

Replacing the cam cover gaskets on the M113 is not a trivial task. Do some serious investigation before you start.

 

I love these wheel too, they almost look OEM. Thanks for the advice, will check out the gaskets. Already ordered an OEM replacement that came in this morning. hopefully his new gasket does the trick.

 

Had to have the valve cover gaskets replaced on my S430. It was the only leak I had.

 

diagnosing oil leaks from the top is kind of difficult, oil cooler, valve covers, cam sensors, you'd get a better angle from under the car with the shields removed. I love your W220, badass car

 

This is because mainly 2 things.
1.Gasket leak which will burn oil and smell comes to cabin, i am facing this now
2.Engine.rear main seal leak the ring type on

 

A little late but the problem ended up being the Valve cover. I replaced the gasket and the problem was gone.

 

Thanks for following up. Thats the most important part of the forum. On first read I said to myself its the VC gaskets. glad you got it sorted easily.

 

there is a plastic port on the drivers side valve cover. poke it out once in a while with small pin or something. it helps the engine pcv work better and less leaks. but the valve cover job is a nightmare i would think