JimKatconowitz

Hello, I was driving my Ml430 2 days ago in stop and go traffic and I let the ml idle for about 45 minutes in total from that day, then went on a short drive home, the next day I left for work and everything was fine and no smoke on the start up but I was driving home I gave a little gas going uphill and got up to 2500 rpm and a cloud of smoke poured out the back tailpipe and the ml has been smoking grey-ish and really off white smoke. The car doesn't overheat and it's not loosing coolant. Could this be the build up of deposit that built up from 2 days before of idling in traffic for too long? I also attached a picture after I put my finger in the tail pipe and it was black and oily, and should I take a long drive on the highway to sort of "clear out" the deposit out of the system? I know this is obviously not normal but any ideas?

Maj. Dundee

Yes it could. Do some spirited driving hitting the kickdown sw. a few times and then change the oil.

JimKatconowitz

Mr.Maj Dundee I'll surely take your advise and go on a long highway drive, and hitting the kickdown switch a few times. I should have mentioned in the first tread that my ml is really only a city car and rarely see's the highway, so I'll try to take the ml out at least twice a month on longer drives to "clear" everything out from stop and go traffic, thanks alot. I also have a "dumb" question, I've been really easy on my ml for the 11 years that I've owned it and I've never really pushed the motor above 2500 rpm, I have very few times, but not much through the years, Should I flat out push the motor, and will it handle sudden high rpms despite being almost used to 2500 rpm as a max, thanks

Maj. Dundee

Absolutely step on it. If you drive it like a 90 yr. old constantly, build-up on valves and cylinders will occur.

Another thing, border line eng. oil could have taken a beating in that 45 min. idle event and the viscosity could have thinned out considerably.

https://en.wikipedia.org/wiki/Viscosity

JimKatconowitz

Hey Mr. Maj Dundee, I've noticed that my ml runs better after I followed your advice. But I was wondering if it matters that my ml430 has 185,000 miles? I'm trying to figure out if the older m113s with higher miles can still be "revved out" every once in a while. If this topic is foolish of me to even ask I'm very sorry, but I'm curious.

Maj. Dundee

No problem whatsoever.