UPDATE on Mercedes Sprinter: Will Not Go, Normal idle in P but RPMs drop in D or R with Engine Lugging Nastily at 400-500 RPM — ***POSSIBLE FIX***
re: Mercedes Sprinter Issues and Breakdowns: Sprinter Will Not Go, RPMs Drop Very Low (Normal idle, put into D or R, RPMs drop, Engine Lugs
re: UPDATE on Mercedes Sprinter Issues and Breakdowns: Sprinter Will Not Move, RPMs Drop Very Low
re: 2017 Mercedes Sprinter: Is it Going to KILL ME by Failing to Move at a Crucial Time?
re: Mercedes Sprinter
Read the first link above in particular to understand the issue.
In brief, at altitudes ~6000 ft and above (perhaps lower), it can take up to 10 minutes before the Mercedes Sprinter will go anywhere, even with the accelerator floored.
Cold exacerbates the issue, but it happens at altitude even when relatively warm eg 50°F or so. It can be extremely dangerous (as in death or serious injury), let alone annoying.
Here is a video taken in October 2022. It shows the same issue as all previous years. This was prior to the mitigation discussed below.
Mitigation that seems to work — Cetane/winterizer and/or BG 245
On a recent 6-week trip, I spent most time at an altitude of 8400 feet. I encountered the “no go” lug-then-stall-and-die problem regularly. Lowest temperatures did not go below 28°F, but the problem happened even after nights well above freezing.
Moving on later in the trip, I spent time at 8000 to 12000 feet in the White Mountains with temperatures down to 20°F or so parked overnight (and as low as 8°F and not above 16°F on one day). I had no issues at all. Indeed, the van/engine was eager to pull away and go immediately upon startup, with no hesitation, no lugging, etc. Engine idle was ideal, and smooth.
The difference? About 100 miles before getting up into the White Mountains, I added:
- To my 48 gallon fuel tank upon fillup, I added Power Service diesel fuel Cetane Boost and winterizer/antigel @AMAZON, specified to treat 100 gallons, eg 2X the suggested ratio for winterizing.
- One quart of BG 245 premium fuel system cleaner @AMAZON.
My hypothesis is that one (possibly both) of these additives was responsible for eliminating the stall/lugging/no-go issue. While this was only one trip, each and every day for 5 days at altitude and cold I had an eager engine right upon startup, with no lugging and no stalling. That defies all prior 5 years of experience as well as the previous 4-5 weeks.
I can think of no other factor that could explain the perfect operation.
My guess woud be that the Cetane booster/winterizer alone did the trick, since I rarely add the BG 245 stuff except on a low tank (maximal concentration/minimum dilution for most effect), and this time I had a full 48 gallon tank, diluting the BG 245 substantially. And since I regularly use BG 245 to clean up crud, I discount the idea that it was responsible. Yet I cannot rule out that it contributed or was even the primary benefactor—I will have to experiment to find out.
Since the past 5 years of stall issues occured sometimes at even relatively warm temperatures (Charles H reports up to 80°F), I dismiss fuel gelling from cold temperatiures as a factor. I’m guessing it is the Cetane boost at work (+8 when treated at 2X the specified ratio?). But I cannot rule out the BG 245 being involved.
Next trip to altitude (cold or not), I will try just the Cetane Booster to see if behavior is good. At over $50/quart for the BG 245, I hope it is the Cetane Booster (about $12).
Quick note on the BG 245
BG 245 premium fuel system cleaner @AMAZON works in my view. The trick I use is to add it only when down to ~6 gallons of fuel so as to have a high concentration in the mix. Even better if you are handy (I’m not) is to add it directly into the fuel filter, start the engine briefly (10 seconds or so), then shut it off and soak overnight (dump the rest into the fuel tank). That should help dissolve away any nasty deposits.
Sprinters get a lot of money put into them. Higher operating costs for frequent oil changes with top-grade oil are massively cheaper than the problems you can run into. If you want to use the garbage-grade oil Mercedes puts into your Sprinter (NOACK 25%, nil zinc to protect the timing chain, very poor ability to handle soot, etc, just horrible stuff not even rated for a diesel engine), be my guest, but the chickens will come home to roost doing so.
Recommendation: change oil every 4000-5000 miles for normal operation, every 3000 miles if the engine is idled a lot. And avoid idling unless absolutely necessary.