Intermittent P0087 on 2011 JSW TDI 160k miles, haven’t been able to pinpoint problem

Joined
May 24, 2023
Location
Northwest Nebraska
TDI
2011 JSW TDI
Hello all,

I’ve been a longtime reader of the forums as I fix odds and ends on this vehicle I purchased from a local used car lot in 2020. No clue what the maintenance history was like, it sat on the dealer’s lot for over a year and was picked up at a big auto auction. I don’t know what the status is of the emissions fix, but I assume any warranty associated with that would be expired.

I’m having a fuel issue that I’m having trouble figuring out. I am getting intermittent P0087 low fuel rail pressure codes and the vehicle drops into limp home mode. Sometimes every 10 miles, sometimes I’ll go 100 miles without it. There’s also a hydraulic-sounding whine coming from under the hood when it happens. I actually thought it was a failing power steering pump the first time I heard it due to the specific sound. However the sound does not change in pitch when turning the steering wheel or raising the throttle.

If I pull over and let the car rest for a minute then restart the engine and start driving it is completely normal until the next time it throws the code. I’ve taken to using my basic Wi-Fi ODB code reader (I don’t have VCDS) to reset the fault codes when it happens so I don’t have to pull over and wait to restart the engine. Doing it this way doesn’t seem to have any affect on how often it happens. My anecdotal experience is it happens more often in the heat, but I also don’t drive it out of town much in the winter so that could also be the reason I notice it less.

After searching the forums and looking around online extensively I’ve done the following:

First, I replaced the fuel filter and found no metal shavings and no other debris.
Second, I replaced the fuel metering valve on the HPFP and checked for metal shavings in the HPFP. Also no debris there.
Third, I have tried tracing the source of the hydraulic whine and it seems to be emanating from one of the lines coming out of the fuel filter.

At this point, I’m not really sure what to do. None of the posts I can find mention any kind of noise like I’m hearing. It doesn’t seem like an HPFP failure so I don’t want to go through the labor and expense of replacing it unless that’s almost certainly the problem. I’ve heard about restricted fuel flow causing issues, but I’m not sure how to diagnose that.

I would appreciate any kind of troubleshooting tips you can offer, and I would be happy to provide more information if it would be helpful. Thank you!!
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
First, there is no power steering pump... that car uses an electric assisted rack, so you can rule that out.

Second, have you placed your hand on the electric fuel pump (the auxiliary pump) under the hood and felt if it was vibrating badly and perhaps the source of your noise? It's in a rubber mounting in a metal bracket right up top near the coolant bottle. It could be failing, OR, the electric lift pump in the tank could be failing and starving the aux pump for fuel.

That would be my guess from your DTC and your description.
 
Joined
May 24, 2023
Location
Northwest Nebraska
TDI
2011 JSW TDI
First, there is no power steering pump... that car uses an electric assisted rack, so you can rule that out.
Good to know, thank you!! I had no idea.

Second, have you placed your hand on the electric fuel pump (the auxiliary pump) under the hood and felt if it was vibrating badly and perhaps the source of your noise? It's in a rubber mounting in a metal bracket right up top near the coolant bottle. It could be failing, OR, the electric lift pump in the tank could be failing and starving the aux pump for fuel.
The sound is coming from exactly that area! Let me reproduce the issue and I’ll report back soon. Thank you so much.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
That aux pump is a Bosch unit, and can be found by searching for the Bosch long number 0-580-464-121. Volkswagen will just sell the whole assembly, which is 5N0-906-129-B but it costs more and so long as nothing is broken in the mounting you can just change out the pump itself.

But the in-tank unit is best serviced as the whole assembly, access panel under the rear seat. Pierburg, Siemens-VDO, or Bosch supply those. The OEM number is 1K0-919-050-AB.
 

Realcamogirl

Member
Joined
Jun 19, 2020
Location
IN
TDI
2012 Jetta
Did you solve this problem? I have the exact same issue with my 2012 Jetta.
First, there is no power steering pump... that car uses an electric assisted rack, so you can rule that out.

Second, have you placed your hand on the electric fuel pump (the auxiliary pump) under the hood and felt if it was vibrating badly and perhaps the source of your noise? It's in a rubber mounting in a metal bracket right up top near the coolant bottle. It could be failing, OR, the electric lift pump in the tank could be failing and starving the aux pump for fuel.

That would be my guess from your DTC and your description.
 
Joined
May 24, 2023
Location
Northwest Nebraska
TDI
2011 JSW TDI
Did you solve this problem? I have the exact same issue with my 2012 Jetta.
I’m so glad you responded, I’ve been meaning to update and I keep forgetting to log in and write it up.

The problem is not solved. I ordered a replacement aux fuel pump and replaced it. The hydraulic-sounding whine was definitely coming from the area of the aux fuel pump, and I‘m fairly certain that it’s the only thing in that area that could produce the sound I’m hearing. However, the new aux fuel pump is making the same sound and I’m getting the irregular P0087 codes.

Performance is about the same as before, I don’t think having the new pump has made a difference one way or the other. When I first replaced it, I felt like it was somewhat better but I don’t believe that any more now that I have some more miles on it. At this point, I’m not sure what to do. I’ve seen some videos on how to diagnose a fuel restriction and I’m going to try going down that road. Perhaps there’s a fuel restriction in the tank or the lines that is causing the aux fuel pump to struggle and start vibrating/making noise??

Sorry to hear you’re having the same issue, good luck to you on fixing it. Hopefully somebody has a few suggestions for us to try.
 
Joined
May 24, 2023
Location
Northwest Nebraska
TDI
2011 JSW TDI
Checking in to ask for some more assistance. The new aux fuel pump is still making the same noise. I took the vehicle for a highway drive after work today and it was popping P0087 codes every few minutes and even started to cut out a little bit before I turned back toward town. I stopped to turn the engine off for a bit and it made it back to town without cutting out.

What is the purpose of the aux fuel pump and what is the flow of fuel through it? I’m trying to work out how to look for some kind of fuel restriction.
 

Tuheeden

Veteran Member
Joined
Sep 18, 2022
Location
North Carolina
TDI
2013 & 2014 Jetta sportwagon
Ok, this will sound crazy but that system CAN run with the fuel lines to the HPFP pump reversed. If someone changed fuel filter and took the hoses off and mixed them up putting them back on, you would get issues like you are describing. I will look at mine in the morning and give you the hose mapping to verify
 
Joined
May 24, 2023
Location
Northwest Nebraska
TDI
2011 JSW TDI
You know, I did have the fuel filter replaced not long before this happened. If you could share some hose mapping information, that would be tremendously helpful. Thank you!
 

Tuheeden

Veteran Member
Joined
Sep 18, 2022
Location
North Carolina
TDI
2013 & 2014 Jetta sportwagon
You know, I did have the fuel filter replaced not long before this happened. If you could share some hose mapping information, that would be tremendously helpful. Thank you!
Dont know if those links will work for you (I still cant figure out how to upload photos....)
However the CJA and the CBA hoses 3 & 4 (the 2 closest to the front of the car) are REVERSED and I have actually done this.
So from back/left to front right - hose 1 is input from fuel tank, hose 2 is output - return TO fuel tank, 3 is output to HPFP, 4 is input from fuel rail (fuel returning from the rail) - So if #3 and #4 are reversed, the car will run but will spit an error under any real load.
 

Tuheeden

Veteran Member
Joined
Sep 18, 2022
Location
North Carolina
TDI
2013 & 2014 Jetta sportwagon
I believe everything is hooked up correctly, but here’s a picture just in case. What do you think?
Yea that looks correct.

Usually the low fuel pressure code on the CP4 fuel pump is either the aux pump, a filter clogged or the HPFP is failing but I think you reviewed all of these options
 

calimustang

Veteran Member
Joined
May 17, 2010
Location
Central FL
TDI
2011 JSW DSG (buyback, RIP), 2014 JSW TDI, 2015 Passat TDI, 2013 Jetta TDI.
oh boy. have you checked the fuel tank? there may be mold/mildew or some kind of debris clogging that makes aux pump to work harder as theres not sufficient fuel flow?

I had the very same whining sounds back in 2018. 5 HPFP failures and 6 months later from 20k miles to 25k miles, the idiots at VW finally thought of checking the fuel tank and BEHOLD! it was caked in mold/mildew from car sitting during the buyback period of 2 years.

they covered it all and the very next day, I slapped the CP3 on and never look back, she chugs flawlessly at 171k miles now.
 
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