New Owner of 2015 Navion 24VP

[Roadburnz]

Hi, We just purchased a new (to us) 2015 Navion 24VP and drove it from Denver to our home in the Houston area. We've been dreaming of owning one for a while and finally decided to not wait any longer and make it happen.
The drive from Denver was fairly uneventful. A couple of issues with items not working as we expected (newbie operator error). One thing that we did notice after refueling the first day was that that the engine seemed to start rattling/knocking under certain load conditions. We're hoping that it has something to do with the quality of the fuel. I plan on taking it in to have a mechanic give a listen.
We've been researching the 24V unit for a long time so of course we have a long list of upgrades/improvements that I plan on doing (TPMS, Sumo Springs, Hellwig Anti-SwayBar, Trik-L-Start, PI Hardwired EMS, etc........).

Looking forward to any wisdom/advice.

[Old Crows]

Welcome! First thing: Are you sure you refueled with DIESEL?????? After your next refueling, did it run OK? If yes, it was probably mis or wrong fueling. A few gallons of gas could be burned off if it was diluted with diesel in the tank. Yes, would run like crap. Next fueling, it could burn out and be OK.

HINT! DO NOT TRUST THE COLORS OF THE PUMP HANDLES!!! Every fuel station uses different color handles. It may be yellow, green (most common), blue.... Look at the label on the pump & follow the hose.... And before you pump... DOUBLE CHECK! (I put a label on the frame of the fill port.... GOT DIESEL????? as a reminder to check.

Any dash lights????

Sprinters are complex and need competent diagnosis of problems. Take it to a Mercedes dealer with a Sprinter service department. They have the scan tools, computers and corporate back up to diagnose and the correct parts to repair/replace defective bits.

It is possible that there is a recall OR an update to the engine management system that has never been implemented.

If it's emission control related, the repair may be covered by the emissions warranty, 10 years/100,000 miles.

[Roadburnz]

Hi and thanks for the reply. Yes, I made sure that we used diesel. The diesel did have “up to 15% biodiesel” so we thought that this may be the problem. It still did the rattle after refueling a couple more times. I haven’t seen any dash lights or error codes. I do plan on going to the local Mercedes dealer and have them check it out. Thanks again for the advice.

[Old Crows]

OK. No lights is very good! Maybe.... If the RV sat around the fuel degraded and it is working its way clear with fresh fuel. Could be a difference in the Cetane rating of the fuels used. Cetane is opposite of octane... It is how easily the fuel combusts.

Another possibility is... You are hearing the "rumble" of the diesel particulate filter being cleaned. It will sound like a big blowtorch. As it cools down the exhaust will ping, chirp, crackle, pop and make all kinds of weird noise. (Sounds like a big air cooled aircraft engine after shut down.) It talks to you. That is all normal. Should happen about every 400 miles +/-.

Occasional use of > 5% biodiesel is not a problem. Mother Benz does not recommend ANY diesel conditioners, additives, or "stuff" added to the fuel. That said... I have used PRI-D because it is stored a lot and it prevents degradation of the fuel.

IME, the 3.0L V6 (OM-642) can be very quiet or sometimes rattle depending on the mood it is in.

FWIW, if you do not have lights on the dash..... If it was mine, I'd run some more fuel through it. If it goes away, so much the better. If the power, performance and efficiency are satisfactory.... I'd say it was them fairies, Gremlins, and wee people being driven off.....

[Roadburnz]

My unit has the 2.4L turbo. When the noise comes it sounds just like a gas car when it has bad gas and starts knocking/rattling right before it downshifts. I have drove it around a little bit since we got home and the noise does seem to have gotten a lot better. But the previous noise seemed worse when the engine was warm so I need to drive it around for a longer time. I just purchased some of the Pri-D so we’ll see if that helps too. Thanks again for the advice.

[Old Crows]

Oh Dear! MY BAD!!! I keep forgetting that Mother started the I4 twin turbo around 2014/15 models. Chassis is often a year earlier than the 'registered' year because they get the chassis sometime before they build out. No big deal. For practical purposes, it's a 2015.

Yes, the I4 twin turbo with the 7 speed close ration box is an awesome combo. Should get about 1-2 mpg better than the V6/5 speed (which is also an awesome setup!) Well, a couple more thoughts if I may....

One of the minor 'adaptive' issues with both our Sprinter RVs (a class B and now our View Profile, C) is the transmission shifting was kind of sketchy until we put 5-7 K miles on it. The issue is that the power management algorithms (V6/5speed) are designed to shift up at lower rpm and stay in higher gears when slowing down to maximize fuel economy. When slowing down, for example, it would stay in 3rd down to say 25 and not downshift. If you tried to 'pull out of the hole' with slow acceleration it would struggle and give what I called the MOOSE CALL. A protesting, groaning, howl for several seconds!!! It would shudder and eventually make its mind up to either downshift... or stop bitching and get on with it. Eventually that has gone away. I attribute it to the engine not making rated torque/power because it was not fully worn in at low mileage. I also believe that the transmission is 'adaptive,' meaning that it learns your driving habits over time. How long that takes is unknown and it may be a perpetual learning process to keep the efficiency high.

I'd try using the 'paddle' shift and just tip it left and then stroke it down a gear or two and see if that helps. These engines are 'high rpm' diesels and will spin up quite well. My OM-642 can easily make about 4200 rpm in lower gears. Not that you would run it there. The OM-642 is best somewhere around 2500-3100 rpm.. While I'm of the opinion that you can't 'lug' a computer controlled automatic, it might be that it isn't yet comfortable working down in the lower rpm range. I don't now about the I4's 'happy' rpm range. Sorry.

Cheers!