My 2014 GL350 gave me a a "Check Fuel Filter" message in the middle of a 2,000 mile drive. The warning popped up in heavy rain, and it did clear the next morning. I think I did feel some power loss for a short while but that also resolved.

I was under the impression my filter was changed when I took the vehicle in for the emissions recall/service, which was not that long ago. It should not have gone bad yet.

Does the warning now mean I need to change the fuel filter? It looks like a half day's labor for me, and some serious risk of breaking old plastic parts that need to be moved for the job. Or instead of replacing it will a couple of treatments of Howe's diesel treat be enough to keep me going?

Also if anyone can access the step-by-step instructions for the procedure, I would be very grateful. The VIN is 4JGDF2EE8EA322575.

 

Looks like a good write up. Much different then my om651 but pretty much same filter, just all the crap ya gotta move to get to it.

https://mbworld.org/forums/gl-class-...42-3-0-v6.html

 

Pouring a fuel system cleaner into your fuel system will not clean the filter.
That said, I've been using 4-10 ounces of the grey bottle Power Service on just about every fill up on all my diesels since about 2001 and have yet to have a fuel related issue with the exception of when I didn't use the additive and the temps got well below -20F - my truck's fuel filter gelled up and had to be replaced. One issue, due to not using the additive. Regular filter changes (every 25K or so?) is not a bad idea.

 

Thanks for posting that, I searched the archives but missed that.

I'm going to have to change the filter, so be it. Do I need new O-rings and seals for the MAF/turbo pipe/other stuff that comes off in the process?

 

Generally a good rule of thumb is yes replace o-rings and gaskets whenever possible. Maybe if you had just done it a couple months prior then probably be ok but those o-rings have probably been in there a long time. Cheapish o-rings will save major headache down the road.

 

Beware that OM642 has CALIBRATED Tee on return fuel line, who made with plastic is easy to break.
Aftermarket offers brass Tee, but those are not calibrated and will lead to engine troubles.

 

Late reply here, but that message likely means there's water in the fuel filter. Not sure if there's a way to get it out without changing the filter. Probably picked up some bad diesel somewhere.