2.1L Warning. Codes - water pump replacement.

lvdaytona

New member
Hello srt4ny....

steps for testing solenoid:

1. check for power and ground at solenoid connector. I used a small pin( from wife's sewing kit) with my dvom to check this, you don't want to try forcing dvom probe in connector. it will damage pins. You need to check for voltage with engine running. Should be system voltage (13-14v)
2. Check source vacuum to the solenoid.
3. Check to see if solenoid is transferring vacuum to water pump.

Hope this helps!
 

lindenengineering

Well-known member
Just a tip
The secret to diagnosing this vacuum solenoid system is with a two channel oscilloscope hooked into the harnesses with piercing probes.

I thought this had gone way with the 1980's Asian cars & huge vacuum system controls with Mukini carburetors .
Now its all back like a another bloody nightmare !
Luckily today I don't need to fire up my old oscilloscope. You can buy two channel hand helds for a not a lot of money.
The easy way to diagnose those pesky issues is just look at solenoid activity with a wave form signal .
Dennis
 
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Mendobob

2014 144" WB 4cyl
My van engine light just came on the other day - with the 2.1L Warning. Codes - water pump replacement - May be a dumb question - but - It does not sound like you want to drive very far before getting fixed... My van is not leaking fluids externally - but the vacuum seal appears to be shot. Dealer is 2.5 hrs away. I do have a competent mechanic but he can't work on it for 2-3 weeks...
 

keshvin

New member
Does anybody know if it is possible to replace a vacuum control coolant pump (A6512001602) with a non-controlled version (A6512001702) on a OM651 in order to eliminate all the coolant/vacuum issues that come with the vacuum controlled version?

Would this throw any fault/CEL?
 
D

Deleted member 50714

Guest
Does anybody know if it is possible to replace a vacuum control coolant pump (A6512001602) with a non-controlled version (A6512001702) on a OM651 in order to eliminate all the coolant/vacuum issues that come with the vacuum controlled version?

Would this throw any fault/CEL?
I haven't read about any, yet. I guess eventually someone will come up with a HACK.

Unless ECU firmware reconfigured, yes it will throw codes.IMG_1903.JPG

sounds like a can of worms to me. Waterpump operation is controlled by ECU to expedite engine warm up. In fact, it doesn't operate for the first 1-3 minutes after power-up.

IMHO, better to keep stock. Unless of course, you possess the necessary knowledge, skills and equipment to make the change.
 

keshvin

New member
Thanks Bobnoxious.

Yeah I wish I could replace the pump to get rid of this problem and modify the sofware so it wouldn't throw an error code. I can also turn on my coolant preheater if it's freezing outside...
 

borabora

Well-known member
It's really hard to gauge from this thread how common this problem really is. It seems an ugly failure that when it rears its head can cause other problems and be expensive to fix. My understanding is that my '16 2500 2.1 does not have a drivetrain warranty anymore since the '16 model only had 36k/36months warranty.
At 81k miles my van runs flawlessly and has apparently been well maintained. I plan on doing long trips to the Yukon and Alaska where the closest MB dealer might be more than 1000 miles away at times. Is the water pump and valve replacement something I should do preemptively because it is such a common failure point??? As an engineer I generally think that fixing things that ain't broke is not a very good idea because the repair itself generates a new failure point.
I'd appreciate any feedback from 2.1l owners and others.
 

avanti

2022 Ford Transit 3500
My understanding is that my '16 2500 2.1 does not have a drivetrain warranty anymore since the '16 model only had 36k/36months warranty.
The water pump is covered under the Diesel Engine Limited Warranty, not the basic drivetrain warranty. Doesn't that go for 5 years/100KK miles on your van?

I don't see any reason to preemptively replace the unit. As far as I know, it does not fail silently. Just don't ignore the failure code.
 

borabora

Well-known member
The water pump is covered under the Diesel Engine Limited Warranty, not the basic drivetrain warranty. Doesn't that go for 5 years/100KK miles on your van?

I don't see any reason to preemptively replace the unit. As far as I know, it does not fail silently. Just don't ignore the failure code.
I think the 2016 model only has 36/36 -- at least that's what google tells me but I have some paperwork that I'll check.
 

avanti

2022 Ford Transit 3500
I think the 2016 model only has 36/36 -- at least that's what google tells me but I have some paperwork that I'll check.
The only thing you can trust is the Warranty manual that came with your van, or a facsimile thereof. You can't trust the Internet. Never enter a dealer's service area without this document in your hand.

Here is yours:

As I suspected, your Diesel engine Warranty is 5/100K, like everybody else's.
 

borabora

Well-known member
Great information, avanti!!! Thank you very much. So, at least I am covered for another 20k miles.
I am wondering if the problem was somehow mitigated in later model years of the NCV3 as that problem must have come to MB's attention by then and often minor changes are made, sometimes without changing the part number.
 

PolySprinter

New member
Hi Borabora -
I also have a 2016 (2500 170WB 2WD w 2.1L OM651 engine). 61,000miles when I bought it; the water-pump was found bad. The local MB dealership covered it under the 5yr/100k engine warranty, as stated above (including the vacuum system).
If yours is not "bad" though (i.e., throwing codes or visibly leaking), I doubt they will touch it, and I agree with the others that it seems like an unnecessarily expensive proposition to fix it preemptively - it will cost you the same later if you need it, past the warranty. Note that the clock starts when the van is first sold (not when manufactured), so you might have more time on your 5yr than you think.
Also check your DPF support brackets... these had a nasty habit of breaking off on these vans, leaving the DPF itself vulnerable to break at the flange ($$$). The brackets were redesigned after 2016 and are said to be much more resilient. I replaced mine (broken too) - that was a $500 job at my dealership (not covered under the US warranty though :(. Interestingly, MB Canada DOES cover it! Grrrr.)
To my understanding, these are the only two major Achilles Heels for that van.
 

borabora

Well-known member
Hi Borabora -
I also have a 2016 (2500 170WB 2WD w 2.1L OM651 engine). 61,000miles when I bought it; the water-pump was found bad. The local MB dealership covered it under the 5yr/100k engine warranty, as stated above (including the vacuum system).
If yours is not "bad" though (i.e., throwing codes or visibly leaking), I doubt they will touch it, and I agree with the others that it seems like an unnecessarily expensive proposition to fix it preemptively - it will cost you the same later if you need it, past the warranty. Note that the clock starts when the van is first sold (not when manufactured), so you might have more time on your 5yr than you think.
Also check your DPF support brackets... these had a nasty habit of breaking off on these vans, leaving the DPF itself vulnerable to break at the flange ($$$). The brackets were redesigned after 2016 and are said to be much more resilient. I replaced mine (broken too) - that was a $500 job at my dealership (not covered under the US warranty though :(. Interestingly, MB Canada DOES cover it! Grrrr.)
To my understanding, these are the only two major Achilles Heels for that van.
Thank you so much for all that information. To some degree perusing this forum can turn one into Sprinter hypochondriac. So far my van is running great and I shouldn't be worried but since I plan these 6-10k miles trips on occasion I need to be pretty careful. I'll take a look at the DPF bracket.
 

elemental

Wherever you go, there you are.
To some degree perusing this forum can turn one into Sprinter hypochondriac.
Understatement of the month candidate here. It is comforting to know that if something goes sprong the forum may have some collective experience to help you make good decisions about what to do, but reading all of the individual, anecdotal accounts of the very worst things that have every happened tends to trigger our brains and may make it difficult to stay rational. Keep calm and drive on.

I had an interesting experience with my Toyota 4Runner when it was nearing the end of its factory warranty period. Just before the factory warranty that covered the engine ended, I had my vehicle in for service to the Toyota dealer from which I purchased it. It was just amazing that the dealer techs determined that my water pump was going bad (I hadn't spotted any sign of problems with it), but lucky for me (said in a very sarcastic tone of voice) they were able to replace it at no cost to me (factory billed for warranty service).

Funny thing... I took the vehicle to a different Toyota dealership (closer to my commute route to work) not too long thereafter (less than a year or 10,000 miles) for service that I was paying for. Following an initial review of the vehicle, the service advisor let me know that my water pump needed to be replaced (at my expense), again despite my not observing any signs of failure. When I told him that was unlikely because it had just been replaced, he actually told me I didn't know what I was talking about and wanted me to prove it to him. I showed him the paperwork just to make sure he knew I knew what was going on; didn't let them touch the water pump, and never went back to that dealership. Funny thing... my vehicle is now 20 years old, with 245k miles on it, with no further replacements of the water pump necessary (so far).
 

T.J.T

Member
2014 with 175,000km

Out of extended warranty by 15,000km (10,000 if you count when I drove it off the lot "new")

Just had CEL come on for this. I checked some vacuum lines and good news is no water in them that I can tell but I am having everything replaced as they suggested it. Doesnt seem like a repair I want to guess at parts.


Earlier in the year I had a low coolant warning come on the dash, it makes sense to me now that I know what this CEL is. I wish it would have triggered the CEL at that time
 

Inertiaman

Well-known member
I'm hoping folks can give me some feedback on whether to be concerned, take any pre-emptive action, or just chill.

I have a 2014 OM651 with 82k miles, original owner. I've had intermittent "low coolant" indicator light issues since December 2017 @ ~ 45k miles. It began during an extremely cold period when I was driving through Iowa (like -30F overnight cold). The light would immediately clear after I stopped and restarted the engine. As I made my way to warmer climates, the light stayed off. Until summer . . . then it would come on every 10 starts or so, but immediately clear on subsequent stop/start. It continued that way for another year. Coolant level on overflow reservoir didn't seem to visually change during that time, it was always above min and just below the seam in middle of reservoir.

With this as the background, I had the van in for scheduled maintenance (transmission fluid, brake flush, etc) at Lynwood MB north of Seattle in April 2019 @ 60k miles. I specifically mentioned these coolant light issues and they investigated. Told me they found no issues or evidence of a problem. I assume this means that there were no coolant related codes in the history. I'm confident that the mechanic was competent and honest on this issue, since he also found a small wallet w/ $300 in it that I had lost a year earlier (trapped in cavity that got exposed when he did airbag recall work) and he returned it w/ all the cash :).

Then in December 2019 I took it to a dealer here in Tucson, 10 days before my 5 year warranty expired, to get a "check up", hoping that would establish a warranty period timing on any still-developing problems if any codes were found. To my disappointment, the service writer wouldn't do anything without me signing off on a $500 charge pre-approval. I was like "look, this has been a problem for 2 years, doesn't that justify looking at it?" He claimed it was irrelevant to warranty because "cooling system isn't the engine, that warranty passed." I was like "you're seriously telling me that the water pump isn't part of the engine?" I got frustrated. They wanted ~$200 minimum for an "inspection" (one hour service minimum maybe??). I ended up leaving without any service or diagnosis, fairly pissed off. Very different experience than the Lynwood dealer.

ANYWAY, to make a short story long, after that dealer fiasco, I got myself some compatible coolant. mixed it 50/50 with distilled water, and added one pint of 50/50 to the reservoir back in January 2020. I never saw the coolant light again. Until today. It lit up on first start, went away on second start. I checked coolant, and its definitely below the level I filled to in January 2020, maybe 8-16 ounces less.

The good news is that I haven't had any CEL lights this entire time. (I assume when people here are saying CEL and code P261F, they mean that there was the "general" CEL light and a scan showed P261F? NOT the the coolant icon light?).

I don't have a scanner. Can I assume that the engine has never thrown a P261F or P0128, if I've never had a CEL?

Any suggestions on the sequence of inspections I should do to try and determine if my coolant loss is related to the coolant in vacuum system? Or a more benign leak/problem? I'm willing to acquire a scanner if helpful (although dreading the 2 day rathole reviewing threads here to select my preferred scanner!!).
 

sprintguy

16+ yrs Master Commercial technician
Here is the proper way to diagnose the vacuum system and coolant pump codes with tips and tricks that I have gained over the years.
1: code check , like the LI document states , question 1 , does the system have low boost codes as well ? The low boost codes with the coolant pump switchover valve blocked code will give you the severity of the damage.
Check #1 : connect a vacuum gauge between the booster and vacuum reservoir, the gauge needs to be "T'ed" in. The gauge should be reading between 800 mBar and above. this check tests vacuum supply after the booster (control side).
Check #2 : shut off engine and perform vacuum hold test at water pump supply after the switch over valve. System should hold vacuum above 800m Bar.
Next check is to apply smoke to the water pump vacuum connection after the switch over valve at the metal pipe. smoke test pump. if no smoke is seen and pump does not hold vacuum then replace pump, switchover valve and vacuum reservoir. note always inspect the vacuum line for crusty white dried coolant or oil. If no oil is found but the white dried coolant is , clean out or replace vacuum lines and check for further contamination of the vacuum system. replace other components based off of visual checks , IMPORTANT !! check the brake booster thoroughly, small leaks can cause issues with boost control.
If you replace the water pump and associated damaged parts then the over temp light comes on usually it is the coolant temp sensor that is the problem, also codes for coolant system not reaching temp can occur.
Note that the coolant pump is only actuated off during cold starting for aprox. a minute or so.
Here are some more trouble shooting tips.
1. always check system source vacuum between reservoir and booster. if low (around 600 mBar or lower ) remove check valve from booster and cap valve off then retest, this will eliminate the booster as an issue (9 out of 10 times low source vacuum is the booster leaking) Just know that a small booster leak will not affect brake performance.
2. the smoke test at the vacuum feed pipe is essential , if no smoke machine is present remove the water pump and gasket block off the oval vacuum port on the plate and vacuum test at the feed pipe . If it does leak off then all that does need to be replaced is the o-ring and feed pipe. You will still have to remove the front adaptor plate.
3. If you are replacing the coolant pump for an external leak, replace the switchover valve and the reservoir anyway. If it is leaking externally there is a high probability that the pump is leaking internally.
4. USE ONLY MB PARTS !!! I cannot stress this enough! Aftermarket pumps (especially with the metal impeller) tend to not extend the slip collar all the way over the impeller vanes.
5. Check the pump impeller and counterbore when removed to verify there has been no contact between the 2 components.
6. If you do not feel comfortable performing any of these steps , bring it to a competent repair facility.

Carl
 

Inertiaman

Well-known member
Thanks for that comprehensive summary Carl.
I acquired a Scangauge II and queried for codes. It showed no current codes and no pending codes. Hopefully that is another positive sign, consistent w the fact I haven't had any CELs.
But I'm wondering how thorough or accurate the SG2 may be in detecting past codes?
Now to find the location of the vacuum reservoir (under the air filter assembly??) and associated vacuum lines to inspect.
I wish I would find a tiny leak somewhere on the coolant hoses to more safely explain my slight coolant losses, but such a trivial leak + 5% humidity here in Tucson makes it hard to find any evidence.
 

sprintguy

16+ yrs Master Commercial technician
Thanks for that comprehensive summary Carl.
I acquired a Scangauge II and queried for codes. It showed no current codes and no pending codes. Hopefully that is another positive sign, consistent w the fact I haven't had any CELs.
But I'm wondering how thorough or accurate the SG2 may be in detecting past codes?
Now to find the location of the vacuum reservoir (under the air filter assembly??) and associated vacuum lines to inspect.
I wish I would find a tiny leak somewhere on the coolant hoses to more safely explain my slight coolant losses, but such a trivial leak + 5% humidity here in Tucson makes it hard to find any evidence.
Ok to answer the coolant loss question, If it takes at least a service or 2 to lose a couple cups , that is normal. over a year span (how many miles) to lose up to a pint I have seen and some I could never find the leak. For some reason the pressure bottle system on Benz cars and vans just go through coolant between services. That is why you or your mechanic should top up the coolant during the service.

Carl
 

borabora

Well-known member
What about this write up that P261F can occur after the van sits for a while?
I had my water pump replaced about 3000 miles ago and everything has been perfect since then. Today after the van sat for about 10 day I drive it and notice CEL within a 1 minute of starting (could have been on from beginning). I drove a bit and it did not clear. Scan gave me a single error, namely P261F which I cleared successfully and it has not come back within 10 miles.

Am I deluding myself if think it might be nothing and simply due to the van sitting for a while (something that has happened before without any issues).

Should I go the shop or should drive and see if the problem comes back???

Thanks gurus!
 

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