Actual rail pressure has fallen below the commanded value under load. On UK common-rail diesels this is one of the most frequent causes of limp mode and cutting out.
P0087 means fuel rail pressure is too low. On UK diesels the common causes are a blocked fuel filter, a weak high-pressure pump or leaking injectors. A filter is £40 to £110 fitted, injector seals £150 to £400, a high-pressure pump £600 to £1,400. Do the filter first.
Answered by Bob — 32 years on the tools, DVSA-approved MOT centre, Birnam, Perthshire.
P0087 — also written POO87, P 0087, 0087 — is the OBD-II code for fuel rail / system pressure too low. Same code, same fix: this page covers every spelling of it.
Fuel rail pressure has dropped below what the ECU commanded — one of the most-searched UK diesel fault codes. On PSA 1.6 HDi, VAG 2.0 TDI CR and Mercedes CDI it usually means a tired high-pressure pump or leaking injectors, but a £25 fuel filter fixes it more often than most garages admit.
P0087 is a fuel & air fault code, typically costing £70–£1400 to put right in a UK garage.
What P0087 actually feels like to drive
- Sudden loss of power on the motorway — car drops into limp mode at exactly 2,500 RPM
- Restarts fine after a key-cycle, then relimps under load 20 minutes later
- Hard cold-starting: cranks for 4–6 seconds before catching
- Uneven idle with a diesel-knock 'nail' from cold
- MPG drops 3–7 mpg before the light even comes on
- Metal glitter in the fuel filter housing = CP4 pump has already grenaded
What causes P0087?
- Blocked fuel filter (check this first — it is cheap)
- Weak lift pump or high-pressure pump wear
- Leaking injector back-leak
- Sticking fuel pressure regulator
- Air drawn in through a perished feed pipe
UK vehicles that throw P0087 most often
- Peugeot 208 / 308 / 3008 / Partner 1.6 HDi (DV6 engine) — 2010–2019
- Citroën Berlingo / C3 / C4 / DS3 1.6 HDi — same DV6 shared platform
- Ford Focus / Fiesta / Transit Connect 1.6 TDCi (PSA-shared DV6)
- VW Golf / Passat / Audi A3 / A4 2.0 TDI CR (CAGA / CBAB) — Bosch CP4 pump
- BMW 1 / 3 / 5 Series 2.0d N47 & 3.0d N57 — high-pressure pump wear
- Mercedes-Benz C 220 / E 220 / Sprinter 2.1 CDI (OM651) — metering valve
- Vauxhall Astra / Insignia 2.0 CDTi (A20DTH) — leaking injector back-leak
- Hyundai i30 / ix35 / Kia Sportage 1.7 CRDi & 2.0 CRDi
- Land Rover Discovery 4 / Freelander 2 2.2 TD4 — CP4 self-destruction
How P0087 is fixed
- Change the fuel filter and retest
- Measure injector back-leakage into a graduated tube
- Test rail pressure against commanded on live data
- Replace the pressure regulator or metering valve
The P0087 misdiagnosis that wastes money
P0087 gets misdiagnosed more than almost any other diesel code. We regularly see cars where a garage has fitted a £900 high-pressure fuel pump when the actual fault was a £25 blocked fuel filter, a £60 in-tank lift pump (Bosch CP4 cars especially), or a single leaking injector overwhelming the pump's return volume. On VAG 2.0 TDI CR and BMW N47/N57 running the Bosch CP4, always cut open the old fuel filter and inspect for metallic glitter before condemning the pump — if you see silver, the whole fuel system (pump, rail, injectors, lines, tank) needs replacing because debris has circulated. If the filter is clean, the pump is almost certainly fine.
What a UK garage should charge for P0087
UK independent garage: diagnostic + rail-pressure live-data test £60–£90, fuel filter replacement £45–£110 fitted, injector leak-off test £45–£70, single injector replacement £280–£520 fitted (coding included), high-pressure pump £600–£1,400 fitted, full CP4 catastrophic failure rebuild (pump + rail + injectors + tank clean) £2,200–£4,500. Main dealer: 40–70% more. Do not authorise a pump replacement without a documented rail-pressure test on a scan tool with diesel-level coverage.
P0087 repair cost in the UK
Most P0087 repairs land between £70–£1400 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Bob's tip on P0087
Before spending a penny, replace the fuel filter with a genuine part (never a cheap eBay filter — they collapse and cause the exact same code) and refill with fresh diesel from a busy forecourt. Ask the garage to log 'actual rail pressure vs commanded' on a scan tool during a road test — if actual tracks within 5% of commanded up to 1,600 bar, your pump is fine and the fault is elsewhere (usually a leaking injector). On PSA 1.6 HDi, run a proper leak-off test with clear plastic bottles: any injector filling more than double its neighbours is the culprit. And if you run a VAG CR diesel or BMW N47, never let it run below a quarter tank — the Bosch CP4 pump relies on fuel for cooling and lubrication, and running low is the single biggest cause of the £3,000 catastrophic failure.
Can you drive with P0087?
It will cut out without warning. Treat it as a roadside risk, not a background fault.
Urgency: high.