Need help diagnosing P0087 - Fuel Rail/System Pressure - Too Low
Thread Starter
Junior Member
Joined: Nov 2018
Posts: 63
Likes: 7
From: DC
2014 E63
Need help diagnosing P0087 - Fuel Rail/System Pressure - Too Low
Hello all,
I have a 2014 E63 with around 66k miles; I occasionally get the P0087 code (Fuel Rail/System Pressure - Too Low) whenever I drive the car hard. CEL comes on and car goes into limp home mode, but after I clear the code car drives normal. I've gotten the code about 2-3 times over the course of 1 year of ownership. Car is stock except for resonator delete and UPD cold air induction kit.
It's the only code that comes up. What do you guys think could be the issue? Faulty fuel sensor? Clogged fuel filter? Do these cars even have external fuel filters?
Thanks for the advise.
I have a 2014 E63 with around 66k miles; I occasionally get the P0087 code (Fuel Rail/System Pressure - Too Low) whenever I drive the car hard. CEL comes on and car goes into limp home mode, but after I clear the code car drives normal. I've gotten the code about 2-3 times over the course of 1 year of ownership. Car is stock except for resonator delete and UPD cold air induction kit.
It's the only code that comes up. What do you guys think could be the issue? Faulty fuel sensor? Clogged fuel filter? Do these cars even have external fuel filters?
Thanks for the advise.
Last edited by crazybear; Sep 30, 2020 at 09:14 AM.
Super Member
Joined: Nov 2011
Posts: 973
Likes: 376
From: Austin, TX
2013 SL550 BiTurbo
the fuel filter is built into the driver's side(Left) sending unit(in the tank). You'll need to change the entire unit as the filter is "not serviceable". Best price I've found so far is here.
Filter P/N(driver's/left side) is: 2184700495
Punp P/N(Passanger's/right side) is: 2184700595
I would monitor/log the HPFP circuit pressure and see what it is doing. Pressure should stay steady and not drop significantly(you'll see a slight drop, when going full throttle, but it should recover almost immediately). Could be a filter or lift pump issue, but you'll usually get a LPFS Low Pressure code before you get a HPFP Low Pressure code. It is possible you could have a faulty HPFP, or a bad injector, or even a faulty HPFP Circuit Pressure Sensor.
Filter P/N(driver's/left side) is: 2184700495
Punp P/N(Passanger's/right side) is: 2184700595
I would monitor/log the HPFP circuit pressure and see what it is doing. Pressure should stay steady and not drop significantly(you'll see a slight drop, when going full throttle, but it should recover almost immediately). Could be a filter or lift pump issue, but you'll usually get a LPFS Low Pressure code before you get a HPFP Low Pressure code. It is possible you could have a faulty HPFP, or a bad injector, or even a faulty HPFP Circuit Pressure Sensor.
Thread Starter
Junior Member
Joined: Nov 2018
Posts: 63
Likes: 7
From: DC
2014 E63
the fuel filter is built into the driver's side(Left) sending unit(in the tank). You'll need to change the entire unit as the filter is "not serviceable". Best price I've found so far is here.
Filter P/N(driver's/left side) is: 2184700495
Punp P/N(Passanger's/right side) is: 2184700595
I would monitor/log the HPFP circuit pressure and see what it is doing. Pressure should stay steady and not drop significantly(you'll see a slight drop, when going full throttle, but it should recover almost immediately). Could be a filter or lift pump issue, but you'll usually get a LPFS Low Pressure code before you get a HPFP Low Pressure code. It is possible you could have a faulty HPFP, or a bad injector, or even a faulty HPFP Circuit Pressure Sensor.
Filter P/N(driver's/left side) is: 2184700495
Punp P/N(Passanger's/right side) is: 2184700595
I would monitor/log the HPFP circuit pressure and see what it is doing. Pressure should stay steady and not drop significantly(you'll see a slight drop, when going full throttle, but it should recover almost immediately). Could be a filter or lift pump issue, but you'll usually get a LPFS Low Pressure code before you get a HPFP Low Pressure code. It is possible you could have a faulty HPFP, or a bad injector, or even a faulty HPFP Circuit Pressure Sensor.
Thread Starter
Junior Member
Joined: Nov 2018
Posts: 63
Likes: 7
From: DC
2014 E63
So I was able to log: lowest fuel rail pressure got was around 1430psi (~98bar) at fuel operating temp and idle at around 700. When I revved it, it would go up significantly. Short terms were fine also. Not sure what else to do. Maybe add a bottle of fuel system cleaner.
Trending Topics
Thread Starter
Junior Member
Joined: Nov 2018
Posts: 63
Likes: 7
From: DC
2014 E63
For everyone else following, I logged this morning and fuel pressure still seemed fine while cruising (1540 - 1760 psi) and for hard pulls (up to 5k rpm) it got up to 2500psi. I didnt see a dip in the psi nor did I get a CEL. I will keep logging and see if I can replicate the issue. Its been really inconsistent.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Joined: Aug 2016
Posts: 60
Likes: 15
ML350, E550 Coupe, 53 F100, 458 Italia, 458 Spyder
For everyone else following, I logged this morning and fuel pressure still seemed fine while cruising (1540 - 1760 psi) and for hard pulls (up to 5k rpm) it got up to 2500psi. I didnt see a dip in the psi nor did I get a CEL. I will keep logging and see if I can replicate the issue. Its been really inconsistent.
Was there a fix? I haver the exact same issue on the same engine
Thread Starter
Junior Member
Joined: Nov 2018
Posts: 63
Likes: 7
From: DC
2014 E63
Super Member
Joined: Sep 2018
Posts: 961
Likes: 103
10-second E550
the fuel filter is built into the driver's side(Left) sending unit(in the tank). You'll need to change the entire unit as the filter is "not serviceable". Best price I've found so far is here.
Filter P/N(driver's/left side) is: 2184700495
Punp P/N(Passanger's/right side) is: 2184700595
I would monitor/log the HPFP circuit pressure and see what it is doing. Pressure should stay steady and not drop significantly(you'll see a slight drop, when going full throttle, but it should recover almost immediately). Could be a filter or lift pump issue, but you'll usually get a LPFS Low Pressure code before you get a HPFP Low Pressure code. It is possible you could have a faulty HPFP, or a bad injector, or even a faulty HPFP Circuit Pressure Sensor.
Filter P/N(driver's/left side) is: 2184700495
Punp P/N(Passanger's/right side) is: 2184700595
I would monitor/log the HPFP circuit pressure and see what it is doing. Pressure should stay steady and not drop significantly(you'll see a slight drop, when going full throttle, but it should recover almost immediately). Could be a filter or lift pump issue, but you'll usually get a LPFS Low Pressure code before you get a HPFP Low Pressure code. It is possible you could have a faulty HPFP, or a bad injector, or even a faulty HPFP Circuit Pressure Sensor.
Thanks
Super Member
Joined: Nov 2011
Posts: 973
Likes: 376
From: Austin, TX
2013 SL550 BiTurbo
Sorry for the late response, new job... Haven't been online in a while...
