baldmike73

Short story is i was driving on the freeway the other day and check eng light came on - took to my shop and he called me today sayin losing compression in cylinder number 1. Car is 2014 E63S wagon with 34K on the clock. To fix said he needs to drop eng and replace cylinder head

Anyone else experience this yet? Said it's becoming more common on this engine due to turbo placement and heat generated by the turbos. Typically affects cylinder 1 and 5. Odd thing is that cylinder 5 usually gets hit first.

Luckily i had purchased a 3rd party warranty through USAA when i bought the car and it expires 7/21/21 or 60K miles. Made a copy of the warranty and took to my indy mechanic (master tech) who is going to read through and then start the process.

The million dollar question is to do cylinder #5 at the time of removal or do #1, remove tune and just enjoy the show and miss the extra GO?

Or get it all fixed, put for sale, and upgrade to a 213 wagon.

Just sharing

mdotk

Weird I have never heard of this being a "common" issue - maybe others have.

NoVAe63s

Might be a common issue found at that particular shop, wink wink.

Mojo20032004

bunch of high hp guys running around close to 100k if not over and havent reported said issues

1MavRick

i think you kinda buried the lede on this one. i have absolutely heard of folks with a tune having issues with cylinders 1 and 5. its due the tunes running excess boost and the heat is higher than normal. i've seen it on the forums and it happened to one of my boys, here in Atlanta, a couple of years ago. not sure if i've ever heard of a stock M157 having those issues, tho. what tune do you have?

baldmike73

yes my bad - my car is not stock tuned from a shop in SD (now out of bis) right before i bought the car 5 years ago -

baldmike73

Update - NIck (owner) of Mercedes of Silicon Valley (indy shop ins San Jose) is the man. Was about to drop the engine for warranty claim and a buddy of his (AMG Master Tech at a dealership) told him try one last thing - take a camera into cylinder #1 and look at the pistons as it could be carbon build - low and behold that final check was the culprit - he sprayed a ton of something in through the plenum and then drove the car at 4K+ rpm plus for 20 mins to get the eng HOT to get the carbon build up to flake off. After a few days of driving/testing/retesting the issue is gone and compression is back to normal - drives just like it did prior. I was really nervous to break the engine wide open and was contemplating selling once fixed - but my baby is back to 100% and on the road. Note to self - drive it once warm, get it HOT and clean it out every once and while -

C32owner

Thanks for the update, valuable post this.

eirp

It’s unlikely that carbon build-up bad enough to result in a loss of compression would show up suddenly with a CEL. You are talking about build up so freaking bad the rings don’t seal or the valves are sticking.

Maybe they got a false low reading the first time around. Pretty common when compression testing.

kenneyd

I have a background as an aviation mechanic, the number one cause of compression loss was always carbon buildup. We would just run them lean and hot... Fixed almost every time

eirp

I don’t doubt that at all. I just doubt that the first sign of the problem in a road vehicle would be a CEL and sudden loss of compression.

baldmike73

Im sure he is not bs'ing me as i'm sure he would have loved to have had a 1$2K warranty job vs the $170 he charged me. He did say that his buddy (AMG Master Tech) at one of the bigger AMG shops in the Bay Area said this has happened on more occasions than he can count and did get in there with the camera to test and did just kenneyd said and it did the trick - i even asked him to keep for a few additional days to continue to drive/test and said it never came back. I am not a tech so I wasn't there to argue. The only thing i argued was that i tried to pay him alot more money to which he wouldn't let me.