Sammy1836

Hey everyone I have a puzzling issue, 2019 W166 GLE hit 100k.

Most of the cars life has been driving smooth highway miles, no SES/CEL on, no codes on OBD scanner yet for some reason whenever I idle for about 5 to 10 minutes or so I have some white smelly smoke coming out of the exhaust. It only happens in idle. Goes away when put in drive.

I noticed it happens only when idling for a few minutes and does not smoke at all while driving or even in when at a stop while holding breaks with car in drive.

At first I feared head gasket, did a test and thankfully wasn’t that.

I have no visible oil leaks and I’m not loosing coolant….

I’ve used Techron complete fuel system cleaner thinking maybe it’s a faulty fuel injector but it’s been a week and no change. I’m thinking of trying Techron Fuel Injection cleaner next…..

But doing some more research leads me to thinking is it possible to be a bad PCV? Or maybe EGR? I’m simply puzzled, figured I’d share here to get some other suggestions?

Thanks in advance 🙏🏼

ygmn

what does it smell like?

White tends to mean coolant and/or water vapor.

Does engine temp have any effect on smoke? cold engine more smoke or less versus hot?
What about outside air temp and humidty? cold, medium or hot? dry or your glasses fog up humid?

What test was done to rule out head gasket?

Sammy1836

Hey, thanks for the reply! It happens only when idling doesn’t have anything to do with outside temperature as this happens when it’s hot or cool out. Humid or not. It’s been this way for a while. Sometimes it doesn’t even happen for months then I find myself idling sending an email or something while parked and I see the dreaded smoke, turn off the car, turn it back on and it’s gone…

I did a chemical test for the head gasket, color stayed blue and I waited for over 10 min testing again and again on two different occasions. Color stays solid so it’s not the head gasket….

ygmn

take pic - is a cloud of smoke like a battleship trying to hide behind smoke screen? or ??

Could be something to do with moisture in exhaust if very little smoke.
ANything else different?
less power? different exhaust sound?
ANy fluid leaks?

What does it smell like?

IF tiny amount of smoke only after idling for few mins could be miniscule amount of liquid

Sammy1836

No loss off power, no difference in exhaust sound, no fluid leaks that are visible to me….

I’ll try and take pictures and a video and post it, actually not a bad idea 🙏🏼👍🏼

Sammy1836

Finally happened again, I was able to record it.

video: https://jmp.sh/x8JNqN1i

now keep in mind, soon as I turn off the car and turn it back on, it’s gone. No smoke again.

ygmn

looks like water vapor -
is it cold and humid?
does it happen after engine up to temp?
What does it smell like? (DEAD RAT?)
DO you park up hill or down hill or in flat garage? IE any dew or collected water in exhaust move towards engine or back out tail pipe when off?

IF it was me and under factory bumper to bumper warranty I would take it in to get logged on file so in case it does tur into anything they should pay for it since you brought it in.

I really think it is just morning dew steaming out tips

Sammy1836

appreciate the reply and wish it was morning due but unfortunately I don’t believe it is.

parking is flat straight, doesn’t happen at all during start up, engine is up to temp, and it doesn’t happen often. Also if you look at the video the way the smoke is coming out isn’t smooth like morning dew or water….

BlownV8

Looks like a blown head gasket to me.