2.1L Warning. Codes - water pump replacement.
- Thread starter therealtimliu
- Start date
srt4ny
Active member
Yes mine was the same way intermittent code no leaks or coolant loss but when I tested the vacuum it wasn’t holding any vacuum replaced pump and all is good now
srt4ny
Active member
Water pumps wear out over time After 125k you got a very good life out of that water pump..I don’t think the water pump is the problem on 2.1 its the fact that the pump is vacuum operated and can do more damage when it fails internally, mechanics often replace water pumps before they fail or while simultaneously making other labor-intensive repairs but failure rates of the pump is not bad I replaced mine once and i now have almost 400k on my 2015 2.1l Of course, some water pumps may not last quite that long just have to keep an eye on it look for the signs
I have now had the Thermostat (housing and sensor incl) replaced and water pump replaced by the dealer due to intermittent CEL with p0128 code. The CEL reappeared after driving 20km after picking the van up. It is going back to the dealer tomorrow for them to check out but I feel as though they may be throwing parts at the problem hoping for the best as opposed to actually diagnosing the issue at hand. Does anybody have any input on what should be done next, I don't really have the right space to deal with this myself currently (-20oC here) so I am partially at their mercy...
This is at a dealership, out of warranty, they scanned and did a "complimentary diagnosis" today all systems are normal according to them.
"First it is recommended you remove the front cover and replace the vacuum hook pipe and O ring that feeds the water pump clutch control .
Most likely you will need to change out the vacuum line part# 9064300331 & change over valve 0025407097, this line contains a hidden check valve which gets contaminated with coolant.
The system MUST maintain & hold a minimum of 23" HG,
Additionally you must check the change over valve & switch & line from the vaccum pump to booster"
This is what you are referencing?
This is the notes that I received from the tech. I feel as though they have been thorough but just want to ensure that my van is in good running condition and not risk further issues.
"Check engine light is on, connect battery charger, connect xentry, preform quick test, found store code p0128 same as previously, check odo found the code came on at 158734 aprox 200km ago, remove air filter housing, remove engine cover, process code, vehicle does not have a thermostat heating element,disconnect vacuum line from water pump, and switchover valve, check for coolant contamination, no coolant, disconnect switchover valve electrical connector and measured voltage at terminal and ground, found batt voltage, disconnect cdi m connector, measured resistance between m connector terminal 71 and switch over valve connector terminal 1, found 0.1 ohms, the resistance measured is ok, measure resistance in the switch over valve found 28ohms the measured resistance is the specified value, check for corrosion and damage atconnector and terminals, all ok, disconnect vacuum lines at at vacuum reservoir and check for coolant or oil contamination, no contamination, remove vacuum at brake booster check for oil contamination, no contamination, start vehicle, disconnect vacuum line at waterpump switch over valve check for vacuum, vacuum is present, connect pressure at the vacuum lines and create pressure, all ok, create vacuum, system holds vacuum, no leak in vacuum system, clear codes."
"First it is recommended you remove the front cover and replace the vacuum hook pipe and O ring that feeds the water pump clutch control .
Most likely you will need to change out the vacuum line part# 9064300331 & change over valve 0025407097, this line contains a hidden check valve which gets contaminated with coolant.
The system MUST maintain & hold a minimum of 23" HG,
Additionally you must check the change over valve & switch & line from the vaccum pump to booster"
This is what you are referencing?
This is the notes that I received from the tech. I feel as though they have been thorough but just want to ensure that my van is in good running condition and not risk further issues.
"Check engine light is on, connect battery charger, connect xentry, preform quick test, found store code p0128 same as previously, check odo found the code came on at 158734 aprox 200km ago, remove air filter housing, remove engine cover, process code, vehicle does not have a thermostat heating element,disconnect vacuum line from water pump, and switchover valve, check for coolant contamination, no coolant, disconnect switchover valve electrical connector and measured voltage at terminal and ground, found batt voltage, disconnect cdi m connector, measured resistance between m connector terminal 71 and switch over valve connector terminal 1, found 0.1 ohms, the resistance measured is ok, measure resistance in the switch over valve found 28ohms the measured resistance is the specified value, check for corrosion and damage atconnector and terminals, all ok, disconnect vacuum lines at at vacuum reservoir and check for coolant or oil contamination, no contamination, remove vacuum at brake booster check for oil contamination, no contamination, start vehicle, disconnect vacuum line at waterpump switch over valve check for vacuum, vacuum is present, connect pressure at the vacuum lines and create pressure, all ok, create vacuum, system holds vacuum, no leak in vacuum system, clear codes."
Last edited:
lindenengineering
Well-known member
AND what does this code P0128 tell you?
Dennis
Dennis
My understanding is that this indicates the engine coolant is not reaching the temperature that the ECM expects it to in a determined amount of time.
I do not know how this determined amount of time is calculated.
I do think that this is related to some type of issue with coolant flow.
I am working with my local dealer to try to resolve the issue, at this point they have replaced two of the major components related to coolant flow (thermostat and waterpump) and they have inspected the vacuum system that your post indicated as a possible trouble spot. The vacuum system does go beyond my understanding at this point but I am trying to gain some understanding of it's operation.
I do not know how this determined amount of time is calculated.
I do think that this is related to some type of issue with coolant flow.
I am working with my local dealer to try to resolve the issue, at this point they have replaced two of the major components related to coolant flow (thermostat and waterpump) and they have inspected the vacuum system that your post indicated as a possible trouble spot. The vacuum system does go beyond my understanding at this point but I am trying to gain some understanding of it's operation.
PolySprinter
New member
This is my first post to the Sprinter forum... must say, I would have liked for it to be in a different thread. But I just bought a 2016 Cargo OM651 170WB with 60k miles. Post-purchase inspection (sadly, couldn't do a pre-purchase one... long story) showed some "weeping" of coolant at the water pump, and they recommended replacing it; I immediately started researching it, and found this thread. I'm a bit confused with the solution steps, however, and that's why I'm posting here...
The very first post (from 4/16/19) explains he had no codes, that they just appeared AFTER he changed both the pump and the changeover valve - which makes his approach seem like the reasonable thing to do... Is the problem fundamentally that the fellow tried to do the work himself, and that that typically has a low rate of success for such a hard problem? Or that he didn't bother also changing the vacuum reservoir, carrier and inspect the entire vacuum system? This seems like a lot of additional work for a problem with no code showing. My van does not have any code showing either, at this point. What would be the preferred course of action? Are the odds of re-occurrence higher on vans that have had this problem once? I get that the answers are going to be somewhat anecdotal, but I think it's still useful.
This is my first van, and I've been dreaming of fixing one up as a camper for 2 years now... I just hope that this problem (which appears to be the Achilles Heel of the 2.1L Sprinter) won't ruin the experience. If the tried-and-true solution is simply to let the dealership mechanic take care of it - and the problem goes away for 300K more miles, then so be it: I'm happy to pay the (higher!) price - just don't want to throw good money after bad if the re-occurence is high even after THEY do the fix. Thanks much for your help.
The very first post (from 4/16/19) explains he had no codes, that they just appeared AFTER he changed both the pump and the changeover valve - which makes his approach seem like the reasonable thing to do... Is the problem fundamentally that the fellow tried to do the work himself, and that that typically has a low rate of success for such a hard problem? Or that he didn't bother also changing the vacuum reservoir, carrier and inspect the entire vacuum system? This seems like a lot of additional work for a problem with no code showing. My van does not have any code showing either, at this point. What would be the preferred course of action? Are the odds of re-occurrence higher on vans that have had this problem once? I get that the answers are going to be somewhat anecdotal, but I think it's still useful.
This is my first van, and I've been dreaming of fixing one up as a camper for 2 years now... I just hope that this problem (which appears to be the Achilles Heel of the 2.1L Sprinter) won't ruin the experience. If the tried-and-true solution is simply to let the dealership mechanic take care of it - and the problem goes away for 300K more miles, then so be it: I'm happy to pay the (higher!) price - just don't want to throw good money after bad if the re-occurence is high even after THEY do the fix. Thanks much for your help.
srt4ny
Active member
If you are having coolant weeping at the water pump thats a good sign means all you probably need is a new pump and you will be good to go its when the pump seal fails internally and the coolant in not leking from the pump but instead gets sucked through vacuum line thats whan you can run into some expensive repairs but thats easy enough to check and diagnose
Does the ambient air temp sensor (whatever picks up temp shown on the dash) have any input on what the ECM expects the coolant temp to be? and if so how much of a discrepancy may cause an issue? I was thinking that the last time we drove down from the ski hill the dash was saying +5.5oC when I would have estimated closer to 0oC we stopped for fuel and when we restarted the van the dash read -1.5oC. This could totally be out to lunch but the "sophistication" of this van is somewhat boggling.
Kajtek1
2015 3500 X long limo RV
The dash thermometer has a probe somewhere on front bumper.
Those probes are not only affected by engine heat when you stop the vehicle, but also are easy affected by evaporating water, melting snow etc.
ECU takes intake air temperature, what I think is part of MAF.
2014 2.1 126K miles
P261F
Question 1:
I have ZERO traces of coolant in vacuum lines @ changeover valve. I'm assuming it's holding the vacuum because I unplugged the lines over an hour after engine was running and I heard the vacuum escape.
Before I tear the whole thing apart would it be a good idea just to replace the changeover valve in case it is stuck? I can do the pump but i don't have any leaks or missing coolant.
Question 2:
What is this "carrier" that takes 9 hrs to replace????
PS. I did oil analysis and have no traces of coolant in the oil
Thanks
Greg
P261F
Question 1:
I have ZERO traces of coolant in vacuum lines @ changeover valve. I'm assuming it's holding the vacuum because I unplugged the lines over an hour after engine was running and I heard the vacuum escape.
Before I tear the whole thing apart would it be a good idea just to replace the changeover valve in case it is stuck? I can do the pump but i don't have any leaks or missing coolant.
Question 2:
What is this "carrier" that takes 9 hrs to replace????
PS. I did oil analysis and have no traces of coolant in the oil
Thanks
Greg
Buying OEM is usually the safe route, but if they fail as early as 60kmi, that's kinda piss poor OEM rec. Not saying there's a better choice i know of.
Kinda like both my 2014 inner tierods going bad within the first 30-40kmi.
pretty sure u get a warranty with OEM pump.
Hi Guys!
I just wanted to relay information about p261f71 on these sprinters. I had a 2014 2.1l that had all the codes mentioned in the Mercedes service bulletin concerning vacuum system contamination. I followed the bulletin and found water pump leaking and coolant in vacuum line, vacuum resevoir, and coolant change over valve. I replaced water pump, reservoir and change over valve. I cleaned out the vacuum lines. Put it all back together, drove it, and all the codes went away except p261f71( change over valve stuck on). After pulling my hair out, and going through the whole system, testing power and ground to switch over valve,and verifying vacuum to/from valve, I found out what an idiot I was..... Turns out that when you order an aftermarket water pump instead of buying a MB genuine part to save money, it bites you in the ass.... The aftermarket water pump that I ordered from Amazon looked just like the MB part at a fraction of the price. The big difference is that the aftermarket part does not have the vacuum sleeve or port. This causes the computer to see a longer than normal warm up period and then P261f71 appears! Please make sure that you verify that the pump has the vacuum sleeve before ordering or installing. I did not think anything of the new pump because I thought the water pump mounting plate had the vacuum sleeve, not the water pump. Anyway, I just don't want anybody else to have to go through this. I ended up buying pump and gasket from local MB dealer....$224 later and code gone...
I just wanted to relay information about p261f71 on these sprinters. I had a 2014 2.1l that had all the codes mentioned in the Mercedes service bulletin concerning vacuum system contamination. I followed the bulletin and found water pump leaking and coolant in vacuum line, vacuum resevoir, and coolant change over valve. I replaced water pump, reservoir and change over valve. I cleaned out the vacuum lines. Put it all back together, drove it, and all the codes went away except p261f71( change over valve stuck on). After pulling my hair out, and going through the whole system, testing power and ground to switch over valve,and verifying vacuum to/from valve, I found out what an idiot I was..... Turns out that when you order an aftermarket water pump instead of buying a MB genuine part to save money, it bites you in the ass.... The aftermarket water pump that I ordered from Amazon looked just like the MB part at a fraction of the price. The big difference is that the aftermarket part does not have the vacuum sleeve or port. This causes the computer to see a longer than normal warm up period and then P261f71 appears! Please make sure that you verify that the pump has the vacuum sleeve before ordering or installing. I did not think anything of the new pump because I thought the water pump mounting plate had the vacuum sleeve, not the water pump. Anyway, I just don't want anybody else to have to go through this. I ended up buying pump and gasket from local MB dealer....$224 later and code gone...
srt4ny
Active member
I have also made a mistake and replaced it with the aftermarket pump the first time and also had a problem so I replaced it with the oem pump and all was good and just recently started getting a p261f71 again..how did you test the change over valve? i did test the water pump and holds vacuum fine no coolant anywhere in lines the whole system holds vacuum