Regen in action?

[Air99]

This was quite alarming, after some idling and driving slowly around Scottsdale AZ looking for propane, restarted the engine and found the engine icon light on, throttle response required a much deeper push. Last time it happened was in Minneapolis, after some slow driving around Lake Calhoun, we were back on the highway I could tell something was amiss, it felt like the turbo gave out, I could not go faster than 60mph but there was no check engine light, then everything returned to normal after an hour of highway speed. We’re currently half way on a cross country trip to Florida, and it happened again, this time it was longer and more lethargic than before. Luckily the I-10 leaving Phoenix was fairly flat but I could not hold 65mph, trying downshift to 4th and stepped on the gas did not help. I even tried the cruise control it actually made it worse by slowing down to 60mph, it was scary when everyone was passing you at 75 or higher. I have read a lot about DEF, EGR, DPF, long idle time etc. and using a particular engine oil for this finicky but powerful motor (for a 3 liter!), if this is indeed the automatic process of cleaning itself of soot and whatever else to meet EPA requirements while you drive, then Mercedes-Benz please give it another system indicator with a countdown timer so as not to totally freak out the owners driving thousand of miles from home, thinking oh s**t I got to find a dealer asap or risk damaging the engine. Long story short, we had to pull to a rest area after half hour of lugging, shut the motor off for awhile. The next drive was better at up 70mph but the CEL was still on and I started seeing slowly improving mileage as well. By the time we arrived at Rock Hound CP in Deming NM, another engine restart and the engine light finally cleared so [emoji28] here’s to love and hate of the beautiful thing! Happy Holidays Everyone and please drive safely out there!

[Protagonist]

Strange.

I've never had anything like that happen on my 2012 Interstate; mine has never gone into anything resembling "limp home" mode (so far; don't want to jinx myself). I'll be very interested to find out what caused it on your Interstate.

It may be worthwhile for you to invest in an OBDII reader, to see what error codes were logged. If the "Check Engine" light came on, then an error code was certainly logged in the onboard computer.

Some error codes may be unique to MB/Sprinter, but knowing which codes were logged will help when you talk to your Sprinter mechanic. By the way, once you check the logged error codes, do not clear them! Leave them for the Sprinter mechanics.

[Pahaska]

On a trip, I can see when the cleaning phase happens by watching the miles per gallon indication. It does not affect the operation of the coach. nor is there any indication on the instrument panel. Typically, my average mpg might drop from 18.5 down to about 17 for a while, then slowly start climbing again. There is no discernible sound or feel.

[GETRIDAONE]

I have never noticed any signs of power loss or warning lights. At a state park we had a very nice lake side spot for one day and had to move for the following day. The office was about a 1 1/2 mile drive to get a tag for the new spot. In the parking lot there was a rather old looking truck and trailer one lane over from me. I could smell what seemed to me liked an over heating motor and said to myself I hope he makes it wherever they going. Arrive at new campsite, back in, get out and the smell has followed me. My first thought was did I leave the emergency brake on for the drive back, is the engine going to quit and have to be towed . It hit me that it was the exhaust cleaning process. The hood was so hot you couldn't keep your hand on it. I left the hood up and let it cool for a few hours before starting it again. It was back to normal and never happened again.

[slowmover]

Re-gen ideally takes only occasionally and then while underway. An engine not “worked” has greater need. An engine too large (power output), subject to stop/go traffic, and with extensive idle time will call for greater number and longer re-gen cycles to keep the emssions/exhaust from restricting.

Besides an OBD-II reader being handy, one is best off reading engine hours and dividing that into total miles. Average mph. Anything below 27-mph is contraindicated for reliability & longevity. (Meaning I wouldn’t buy one with lower than that).

When I purchased my pickup it had an extraordinarily high 47-mph average. That owner must not have gotten off the highway except for cigarettes and diesel. It assured me that high odometer miles wasn’t a problem (which has born out the ten years since).

Ideally one would want to see at or around 35-mph as a rule of thumb. Engine B50 life is calculated at this range. The Cummins in my pickup is essentially a 10,000-hr engine (350k miles at 35-mph). At that point it’s expected that 50% of engines in described service will require a rebuild.

Everyone wants fuel mileage, granted. Eliminating idling, never stopping while on a route avoiding left hand turns, is SOP for best metro delivery service. Low-rpm and light load just doesn’t heat up a Diesel engine sufficiently. EGT above 1000F for extended periods is the thing.

Too large a motor for specification is a classic problem. Then is operator error.

An engine hour meter has a reading valuable to track. If it means changing habits at the wheel, so much the better. Safety & longevity tend to track each other. Divergence is a fair distance out.

.

[InterBlog]

We got the Bluetooth OBD device that is about the size of a plum and remains plugged into the port (unless one wants to remove it). My husband had been managing it, but I recently put the OBD Fusion app on my iPhone (about ten bucks).

[Titus]

I have never noticed a regen while driving. We don't do much in-town or stop and go driving, so we probably encounter few forced regens. We were going up a long hill and stopped at an overlook at the top. I did not notice reduced power during the climb. But when I got out (left the engine running since I expected it to be a short stop) I noticed a burnt sugar smell. Placed my hand at the exhaust pipe and it was very very hot. Much hotter than I would have expected at idle even after the engine was worked hard. So I suspect that I interrupted an unforced regen (unforced means the exhaust temperature was hot enough long enough to cause the soot to burn out on its own). I did not notice the idle speed being elevated while parked - which is what some manufacturers do when a regen is interrupted. As a curious engineer I agree it would be nice to know if/when a regen is occurring, but don't know what I would do with that information.

The comment about a hot hood is odd. A regen would cause the particulate filter (exhaust system) to be hot more so than the hood.

A forced regen may cause mpg to drop (extra fuel is burnt to increase the exhaust temperature to force the regen) but an unforced regen should not impact mpg.

[Air99]

Thanks for all your input, now I’m thinking it’s best to let the dealer look at it, after a family get together in NOLA. Any reputable place to recommend?

[wachuko]

Interesting... I have a code reader (iCarly) for my BMW X5 diesel where I can monitor when these happen... but have not been able to find a code reader for the newer Sprinter (iCarsoft only works up to 2014 Sprinter).

For pre-2014 Sprinters, Matt (Sprinter forum) is giving forum members a discounted price... it was him that told me it would not work with mine when I tried to order one... I never got the discounted price from him since it was not going to work for mine... (you can also find them on eBay for around US$150.00)

https://www.youtube.com/watch?time_c...&v=VYNT_Jv8_o0

Here is the link to that reader thread:

https://sprinter-source.com/forum/sh...ad.php?t=46155

And for the discounted price and process to buy:

How to get it. It is available from multiple sellers on Ebay. Please see this thread regarding a discount.

So if anyone knows of one that would work for the newer Sprinter, do share. Not looking for generic OBDII readers, I have one of those already. Looking for something like folks have for the earlier ones with all those specific Mercedes Sprinter monitoring and change functions.

.

[Boxster1971]

Originally Posted by Air99

Thanks for all your input, now I’m thinking it’s best to let the dealer look at it, after a family get together in NOLA. Any reputable place to recommend?

Good idea to get it checked out by dealer with proper code reader. Someone on the Sprinter-Source forum recently reported similar limp mode issues he thought were associated with DPF Regeneration, but it was actually a turbo seal issue.

I use an Ultra Gauge OBD tool to monitor six engine parameters. The two available catalytic converter (CAT) temps tell me when in regeneration as temps go to 1200F to complete the burn of diesel particulates in the filter. I use the information to minimize interrupting a regeneration if possible.

[amirm]

Ah, I had no idea was such a thing. Were driving to Banf and when we stopped, I thought we had an electrical fire. The engine bay was very hot and I could smell overheated plastic. I looked around but could not find anything. But was still worried. Now I know! Thanks a bunch everyone.

[WillieJ]

Originally Posted by Air99

Thanks for all your input, now I’m thinking it’s best to let the dealer look at it, after a family get together in NOLA. Any reputable place to recommend?

If you are going farther East, I had competent service from the Mercedes dealer in Mobile, AL, when the DEF tank heater failed and the upstream and downstream NOx sensors failed. They caught the NOx sensors that the dealer in Corpus Christi missed during our spring trip.

Otherwise, look for a dealer that sells a higher volume of Sprinters and therefore services many. Not all MB dealers have a high level of competence with Sprinters.

[Air99]

Originally Posted by WillieJ

If you are going farther East, I had competent service from the Mercedes dealer in Mobile, AL, when the DEF tank heater failed and the upstream and downstream NOx sensors failed. They caught the NOx sensors that the dealer in Corpus Christi missed during our spring trip.



Otherwise, look for a dealer that sells a higher volume of Sprinters and therefore services many. Not all MB dealers have a high level of competence with Sprinters.

Much thanks for the tip, we’re currently driving eastbound on I-10, trying to reach Nola by Xmas eve rendezvous and staying through new year, then heading east to Florida, so we will use your recommendation. Quick update, we had a “check DEF fluid” warning after another CEL and limping event, we used Loves truck stop to fill DEF and what a hassle it was due to the filler neck being so small, the nozzle fit snuggly so I had to barely squeeze the trigger, if overfilled it will definitely spray you, what a mess it was! It took 3 gallons and no CEL or limping since, finger crossed but I still want to see the codes. You guys are awesome [emoji122] always!

[Protagonist]

Originally Posted by Air99

Much thanks for the tip, we’re currently driving eastbound on I-10, trying to reach Nola by Xmas eve rendezvous and staying through new year, then heading east to Florida, so we will use your recommendation.

If you have time, Mercedes Benz of Baton Rouge has always given me good service. But sometimes they take longer than I'd like…

[Air99]

Our Dumbo went into severe limp mode late yesterday again but luckily we were able to book a visit to Mercedes-Benz of Boerne (big outfit that also carry Sprinter and Metris) just northwest of San Antonio this morning. Two hours later including test drive they found and replaced a pressure (or temperature, not sure) sensor on the exhaust side that failed intermittently and we were back on the road again with a great sense of relief. So it was not a regen behavior after all. Mysteriously though, out of desperation yesterday when we doing 35mph uphills, thinking it was bad fuel I bought from a small town near our campground on the previous day, we refilled the tank when it was half empty with big name station on the freeway and Dumbo immediately took off and ran great until the dealer visit, could it just be me turning off/on the ignition or if bad diesel really made it worse with the failed sensor ...[emoji848]...Tech said it is a computer on wheels nowadays with most vehicles and you just got to be prepared for plan B. We had no issues with the last 380 miles trip today but my hair is definitely more gray!

[Air99]

We’re home now and I would like to give another update on the engine behavior during our 15km and 3 months cross country trip:
As we drove around St Petersburg FL, about 1,200 miles after first dealer visit, it went into limp mode again but without the check engine light, we had to drive it to Crown EuroCar Mercedes-Benz dealership, a tech did another system “reset”, and they also pulled the MB service records but did not see any repair or replacement data from my earlier visit to Boerne, this just baffled me. This time though whatever they did to Dumbo he just flew all the way home, 5500 miles later. I’m inclined to think it was possible that I was WAY low on DEF fluid during this trip (I added a total of 7.75 gallons between 46.5 and 52.8km!) and that may have triggered the computer to remind (punish) me until a complete reset from the second dealer. By topping off the DEF tank again at home, the consumption rate appeared to be about a gallon in 3000 miles. I need to change my habits and should always top it off before any long trips, as someone here suggested, rather than a gallon every now and then just to avoid the mess it create from overfilling. It really is amazing how much power and torque the little motor produces when everything is working right, finger crossed, and gets 18-20mpg pulling a 5-ton elephant ;-)

[FlyFishinRVr]

Originally Posted by Air99

whatever they did to Dumbo he just flew all the way home
.
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Glad everything worked out.

Oh, and it's the feather.....

[PKI]

Boy, got to have been a deep dive to pull that gem to the surface. Unless, of course, Grand kids! Pat