Sprinter Mercedes Trouble Survey pls contribute

[jackfish]

Originally Posted by Deny

Do not let the light come on because of low DEF level. Then you do not have to worry about it not going out.

Just Fill the tank after every trip-and- if you are on a long run- fill it about every 4th tank. Keep a little DEF with you as you travel

I don't think so.

[lindenengine]

Originally Posted by jackfish

I don't think so.

Just for info
There are three sensors in the tank.
As the level runs down they go progressively into "dry mode".
Normal top off should make them go "wet" again.
In some occasions due to several reason they won't reset even after a few key and drive cycles.
A suitable MB scanner can access the Adblue or Adblurr system as I tend to call it and reset the system.
It is not unknown to have communication problems and suspect connection issues on the tank sensors themselves; especially if you have a leak and white DEF crystal deposits are present on the tank carcass.
Dennis

[S Bradley]

Now that is a good exchange of information.

Keep it coming so we can all learn more about our Mecedes.

How to recognize issues and hopefully prevent them or at least minimize potential problems.

[MarsMan]

2015 Coachmen Prism 24J on a 2014 MBS 3500 Chassis.
At 10,000 miles no issues
no DEF added as of yet (will top off before next trip)
averaging approx 20mpg
brakes were spongy when we first test drove it
Weight with full water, 1/2 tank of fuel, empty waste tanks, 2 adults and all supplies 10,600 lbs
need to drive it in 4th and avoid D at speeds less than 60. Seems to be more responsive and the system does not seem to strain. I have always felt the tranny sifts too soon for these heavier rigs on the MBS

[User1011]

Keeping the DEF reservoir tank topped off is fine. For some reason this seems to be a hotly debated conversation. A Sprinter service supervisor at a Mercedes Benz dealership confirmed that there is absolutely no harm in doing so. It is nothing more than a tank just like your fuel tank or your windshield fluid reservoir. All can be kept topped off -- no issues. Not saying you need to top off the DEF all the time but it can be topped off every 2000 miles or so; whatever you wish.

Our DEF tank is 3.2 gallons. We used approximately ~1.5 to 2 gallons for 4000 miles. This equates to about 3 cents per mile. As "lindenengine" states there are several sensors in the tank. If you ignore all - it will necessitate a 'tow' to a service center. It's about the same as if you run out of diesel fuel --- ain't gonna go anywhere either.

[User1011]

Typo -- should have been 0.003 cents per mile --

[lindenengine]

On thing to bear in mind is quality of the DEF fluid itself.
It may well be full in the storage tank but is that fluid good enough to neutralize the pollutants in the exhaust system?

Normally speaking fluid obtained from a reliable source should meet the specs but it does have a shelf life and the urea can turn to crystals especially in RV applications where prolonged storage is often a fact of life.
Winter thaw & freeze up of the fluid, and separation can cause the fluid to degrade. This will cause system operation problems and warning light illumination which are not always easy to remedy once you get under way for your summer driving season.

One active test is to actually check the pump and injector operation, done obviously with a suitable scanner.

The system should develop 5000 HPa of inject pressures and two RV units I have seen recently only produced around 3500 HPa . The dealer wanted to change out the pump and injector at about $2500 tariff, when in fact I cured it by simply draining the tank and filling it with fresh DEF fluid ridding the tank of dormant crystals suspended in the tank, then conducting a few tests.
Cost was around $250.
Hence if your RV has spent a long stretch of storage time without use consider flushing out the tank and filling it with fresh DEF fluid. Might save you some holiday spending money.
All the best and having mentioned this to one dealer who supplies my parts I notice they have now started offering DEF flush services on all Sprinters--How strange!
Dennis

[lindenengine]

On thing to bear in mind is quality of the DEF fluid itself.
It may well be full in the storage tank but is that fluid good enough to neutralize the pollutants in the exhaust system.

Normally speaking fluid obtained from a reliable source should meet the specs but it does have a shelf life and the urea can turn to crystals especially in RV applications where prolonged storage is often a fact of life.
Winter freeze up of the fluid, and separation can cause the fluid to degrade. This will cause system operation problems and warning light illumination which are not always to remedy once you get under way for your summer driving season.

One active test is to actually check the pump and injector operation, done obviously with a suitable scanner.

The system should develop 5000 HPa of inject pressures and two RV units I have seen recently only produced around 3500 HPa . The dealer wanted to change out the pump and injector at about $2500 tariff, when in fact I cured it by simply draining the tank and filling bit with fresh DEF fluid ridding the tank of dormant crystals suspended in the tank.
Cost was around $250.
Hence if your RV has spent a long stretch of storage time without use consider flushing out the tank and filling it with fresh DEF fluid. Might save you some holiday spending money.
All the best and having mentioned this to one dealer who supplies my parts I notice they have now started offering DEF flush services on all Sprinters--How strange!
Dennis

[eestork]

Originally Posted by eestork

2013chassis, 2014 thor citation coach with slide out/curved dinette class b+:
rear end-dually replaced at 2500 miles, skylight entirely replaced, refrigerator electronics replaced all in first year. nothing so far in second year at 14,000 miles.

high pitched whine with touching accelerator--they wanted me to wait for 12,000 miles--are you joking? no sound after replacement.

[mike in tx]

Well, after several more weeks at Mercedes, hopefully the problem has been cured with the sudden stoppage. It seems that it was related to the fuel pressure sensor all along, but specifically was related to the electrical connections sending info to and from it. I was told that the technicians have re-staked the electrical connections, which were apparently loose and sending faulty information, showing high fuel pressure at low speeds and idle, so would shut off the fuel supply to the engine. In the beginning, I suggested there might be a problem with the fuel sensor, just from the way it acted when it would die. The only way to kill a diesel is shut off the fuel supply, as it does not rely on an electrical charge to detonate the fuel. Hopefully, this ongoing problem is history, and we can enjoy our rv more. Of course, now we are waiting for the new high pressure propane line to be replaced again with the Winnebago factory recall. We were probably part of the reason for that recall as our first propane line blew as we were traveling down the highway in August 2015. It was replaced with another of the same part number, which Camping World said needs to be replaced again with the new part number line, but is not available at this time...We really like the Sprinter chassis rv's, but are having a hard time getting the bugs out of this unit..

[thomasd923]

Have re-occurring issue with check engine lamp on. SCR below threshold, third time. Had long term adaptive memory reset (knew that was not a fix!), software update and most recently the cleaned the dosing valve, claiming that it had def crystallized on the valve. So now I need to wait til spring to see if it is finally fixed. Also my shaft for the slide out broke while on a trip, that was a huge headache...Thor could not tell me who made it, but thankfully a persistent customer service rep got the answer. Then Lippert said the parts are no longer available! Finally they found some parts so I ordered 2 sets. Gear rack was never properly secured by Thor, only 2 bolts used out of 4, had to drill holes for additional bolts. They never bothered to remove the adhesive backing for the heaters on the black and gray tanks so the pads didn't make contact. Other than that I really enjoy it!

[lindenengine]

Originally Posted by mike in tx

Well, after several more weeks at Mercedes, hopefully the problem has been cured with the sudden stoppage. It seems that it was related to the fuel pressure sensor all along, but specifically was related to the electrical connections sending info to and from it. I was told that the technicians have re-staked the electrical connections, which were apparently loose and sending faulty information, showing high fuel pressure at low speeds and idle, so would shut off the fuel supply to the engine. In the beginning, I suggested there might be a problem with the fuel sensor, just from the way it acted when it would die. The only way to kill a diesel is shut off the fuel supply, as it does not rely on an electrical charge to detonate the fuel. Hopefully, this ongoing problem is history, and we can enjoy our rv more. Of course, now we are waiting for the new high pressure propane line to be replaced again with the Winnebago factory recall. We were probably part of the reason for that recall as our first propane line blew as we were traveling down the highway in August 2015. It was replaced with another of the same part number, which Camping World said needs to be replaced again with the new part number line, but is not available at this time...We really like the Sprinter chassis rv's, but are having a hard time getting the bugs out of this unit..

This is an interesting post.
I have come across a growing number of Sprinters with this issue and all have had water in the fuel.
The van doesn't have a full blown water sedimenter like many NA brands so care has to be exercised when fueling up.
Fuel stations that do not have high diesel fuel turn over are suspect as water condensation builds up in the storage tank and you then buy this fuel only to experience cutting out and stalling!
Water in the Bosch fuel system will play havoc with the operations often injuring the in tank LP pump and the HP FIE pump in the front of the engine.
Costs can range from about $6500 to fix just the basics up to about $14,000 if the whole FIE system needs to be changed due to water and rust/ contamination in the vital components.
For this reason I recommend you bunker up at truck stops where big rigs fuel.
All the best
Dennis

[lindenengine]

Originally Posted by thomasd923

Have re-occurring issue with check engine lamp on. SCR below threshold, third time. Had long term adaptive memory reset (knew that was not a fix!), software update and most recently the cleaned the dosing valve, claiming that it had def crystallized on the valve. So now I need to wait til spring to see if it is finally fixed. Also my shaft for the slide out broke while on a trip, that was a huge headache...Thor could not tell me who made it, but thankfully a persistent customer service rep got the answer. Then Lippert said the parts are no longer available! Finally they found some parts so I ordered 2 sets. Gear rack was never properly secured by Thor, only 2 bolts used out of 4, had to drill holes for additional bolts. They never bothered to remove the adhesive backing for the heaters on the black and gray tanks so the pads didn't make contact. Other than that I really enjoy it!

The re-flash is to change how the DEF fluid is being injected as it has a tendency to cause condensation in the refractory cracking the ceramic section NOx sensors. If properly re-flashed the CEL WON"T come on within 200 miles, Beware and call the dealer if it does.
MB are on their third re-flash of this system.

I find crystal separation is common on RV's due to lay up times; hence I recommend a tank flush at the start of the driving season.
Cheers Dennis

[Camper Ken]

Lindenengine:
If I drive my motorhome once a month, say for 25-40 miles during periods of "storage", will this prevent crystalization problems with the DEF?