GL350 hard idle in cold and altitude
 

Hi

Been driving our new to us 2011 GL350 from Boulder to Denver recently for skiing. Great ride and acceleration up the mountains.

But, then when I get to about 8500 feet, the truck starts to idle really hard. If I put in neutral, the hard idle goes away. It seems to only happen when it's cold (20-30F) range.

Today, when heading into breck crawling due to snow on the roads, it started doing it again. By the time we pulled in to park, we could also smell something strong, chlorine or something.

The behavior is not consistent - but has happened three times. And it's not just cold related - drove it across country in 10f weather and had no idle or smell issues.


Any ideas.

Could the smell be ammonia? If so there may be something weird going on with the Diesel Emissions Fluid (Adblu) system.

Have your transmission looked at. You mentioned it idled fine when you put it in Neutral?

These turbo diesels run great at altitude an in cold, IF the fuels and fuel additives are good. (I live in IL and drove my ML CDI to the top of the Rocky Mnt via Estes Park. Really nice there.)

Come to think of it, there was a post somewhere in which a member had issues in the same area, and he traced it back to bad fuel from a station near the bottom of the mountains in that area. After he drove out that tank, the issue cleared up and never returned.:nix: