Openai/69606181-ab0c-8001-96cc-1653bd658833

This conversation was exported from ChatGPT

gpt-5-2

User: P0087 fault code

P0087 fault code

Assistant: P0087 is a Fuel Rail/System Pressure Too Low fault code.

P0087 is a Fuel Rail/System Pressure Too Low fault code. In plain terms: the engine isn’t getting enough fuel pressure compared to what the ECU expects.

!https://cdn11\.bigcommerce\.com/s\-m32opxf6o2/images/stencil/original/products/10781/813483/12686809\_media\_01\_\_70584\.1764615810\.jpg?c=1 !https://marvel\-b1\-cdn\.bc0a\.com/f00000000270532/www\.underhoodservice\.com/wp\-content/uploads/2022/11/Fuel\-Pump\.jpg !https://m\.media\-amazon\.com/images/I/71Ka1FYzsiL\.jpg 4

The ECU monitors fuel pressure via the fuel rail pressure sensor. If actual pressure stays below target for a certain time/load condition, it throws P0087.

This usually shows up under:

• Acceleration
• High load
• Cold start
• Hard driving / towing

- Loss of power (especially under load)

• Hard starts or extended cranking
• Rough idle or stalling
• Limp mode
• Check Engine Light
• Poor fuel economy

###

• Low-pressure pump (in-tank) or
• High-pressure pump (direct injection engines)

- Very common if the filter is overdue

• Can cause intermittent pressure drops

- Stuck open → pressure bleeds off

• Electronic regulators can fail silently

- Sending bad data → ECU thinks pressure is low

• Often sets P0087 + related pressure codes

- Restricted fuel line

• Kinked hose
• Bad fuel (water/contamination)
• Low fuel level (yes, this can matter)

- Pump relay

• Wiring voltage drop
• Corroded ground

If you want to be efficient and not throw parts at it:

- What RPM?

• Load?
• Speed?
• Fuel pressure commanded vs actual

- Mechanical gauge (low-pressure side)

• Scan tool live data (rail pressure)
• Compare idle vs acceleration

- Fuel filter age

• Fuel level
• Listen for pump priming
• Check for fuel leaks

- Voltage at fuel pump under load

• Ground integrity
• Pump relay operation

- Does pressure reading make sense when key-on?

• Any sudden drops or flat-lined values?

Running lean due to low fuel pressure can:

• Overheat pistons
• Damage injectors
• Cause detonation
• Kill catalytic converters

If the car feels gutless under load, don’t push it.

- Fuel filter replacement (cheap, often overlooked)

• Fuel pump replacement (most common true fix)
• Fuel pressure sensor (moderate cost)
• Wiring repair near pump or rail

If you want, tell me:

• Year / make / model / engine
• Gas or diesel?
• When the code appears (cold start, highway, hard acceleration)

I’ll narrow this down to the most likely single cause for your vehicle instead of generic advice.

User: 2014 Audi Q5 2.0

2014 Audi Q5 2.0

Assistant: Got it — 2014 Audi Q5 2.0T EA888, direct injection.

Got it — 2014 Audi Q5 2.0T (EA888, direct injection). For this specific platform, P0087 has a very clear “greatest hits” list, and we can narrow it down fast.

!https://strperformance\.com/64179\-large\_default/20\-tsi\-high\-pressure\-cam\-follower\-hydraulic\-pump\-tappet\-fuel\-system\-20\-tfsi\-engine\-ea888\.jpg !https://storage\.googleapis\.com/rp\-production\-public\-content/64o9o0dp56q703i4jgm20xb7yd8c !https://www\.europaparts\.com/media/catalog/product/cache/abf26066ecd46d435ee2486b4a5aee03/8/r/8r0919051n001\.jpg 4

The ECU is seeing fuel rail pressure drop below target, usually under acceleration or load.

On this engine, that almost always points to a supply-side issue, not injectors.

###

This is the #1 known failure on EA888 engines.

• The HPFP is driven by a cam follower
• When the follower wears: - Pump stroke shortens - Rail pressure drops - ECU throws P0087
• Often happens without noise
• Can cause camshaft damage if ignored

Classic signs

• Loss of power on highway on-ramps
• Hesitation above ~3k RPM
• Code appears only under load

⚠️ If the cam follower hasn’t been inspected/replaced, this should be priority #1

Audi uses a filter + pressure regulator assembly.

• Clogs over time
• Starves HPFP
• Very common if filter is original

Interval reality

• Audi says “lifetime”
• Reality: 60–80k miles max

Cheap fix compared to pumps.

- Supplies fuel to the HPFP

• Weak pump = HPFP can’t keep up
• Often shows: - Long crank - Pressure drops under load - Sometimes paired with P310B

- Usually sets implausible signal codes

• Flatlined or erratic readings
• Not the first thing to replace

- Pump control module

• Ground under rear seat
• Relay fatigue

###

Look at:

• Specified rail pressure
• Actual rail pressure
• Compare at: - Idle - Steady cruise - Hard acceleration

If actual falls behind target → mechanical issue.

This is fast and decisive.

• Remove HPFP (top of engine)
• Inspect follower: - Flat = OK - Dished or punched = problem
• If worn: - Replace follower - Inspect cam lobe - HPFP may also need replacement

- Verify pressure at idle and load

• If low side can’t maintain pressure → pump or module

Continuing to drive with P0087 on this engine can:

• Score the intake cam
• Destroy the HPFP
• Lead to $3–5k repair instead of $150–600

This is one of those “small fix now vs big fix later” Audi problems.

1️⃣ Mileage

2️⃣ Does it happen only under acceleration or also at idle? 3️⃣ Any other codes (especially P310B, P2293, P0089) 4️⃣ Original fuel pump / filter?

Once I have that, I’ll tell you exactly what to replace first — no parts cannon.

User: 118k miles

118k miles

Assistant: At 118k miles on a 2014 Audi Q5 2.0T, P0087 is no longer a “maybe” problem — it’s a known wear-out issue.

At 118k miles on a 2014 Audi Q5 2.0T, P0087 is no longer a “maybe” problem — it’s a known wear-out issue. Based on mileage alone, here’s the straight, no-BS answer.

!https://www\.ttforum\.co\.uk/attachments/screenshot\-2022\-10\-29\-at\-16\-19\-14\-png\.493327/ !https://image\.made\-in\-china\.com/365f3j00VRyBPuNdynkl/06e127025n\-06e127025q\-High\-Pressure\-Fuel\-Pump\-for\-Audi\-Q5\-2009\-2012\.webp !https://i\.ebayimg\.com/images/g/MLwAAOSwSv1fIKKd/s\-l1200\.png

###

At 118k:

• The cam follower is almost certainly worn
• Many fail between 90k–120k
• Once worn, the HPFP cannot build enough rail pressure
• ECU throws P0087 under load

⚠️ This is time-sensitive If the follower punches through, it eats the camshaft → $3k+ repair.

###

Pull the HPFP and inspect the cam follower

• Takes ~30–45 minutes
• Very cheap part
• 100% diagnostic certainty

Outcomes:

• Follower worn/dished → Replace follower + likely HPFP
• Follower punched → Stop driving → cam inspection required

Replace the fuel filter (integrated regulator)

• Original filters at 118k are usually restricted
• Starves the HPFP
• Common contributor to P0087

Even if it’s not the root cause, it will become one soon.

Test low-pressure in-tank fuel pump

• Weak pump = HPFP can’t keep up
• Especially shows up during acceleration
• Often paired with hard starts

❌ Replace injectors

❌ Replace the rail pressure sensor first ❌ Ignore the code and “see what happens”

Those are how people turn a $200–600 fix into thousands.

Until this is addressed:

• Avoid hard acceleration
• Avoid highway pulls
• Do NOT tow
• If it goes into limp mode → stop pushing it

Lean running on this engine kills parts quietly.

At 118k, this is no longer diagnostic speculation.

This is maintenance debt coming due.

If you want, tell me:

• Do you wrench yourself or shop only?
• Any other codes present?
• Does it hesitate mainly above 3k RPM?

I’ll tell you exactly which parts to buy (OEM vs aftermarket, what’s worth upgrading, what isn’t).

User: Just more info

Just more info

Assistant: Perfect — that Reddit post actually confirms what I was already leaning toward, and it rules a few things out.

Perfect — that Reddit post actually confirms what I was already leaning toward, and it rules a few things out. Let’s tighten this down.

Key takeaways from the “more info”

You didn’t just get a random P0087 — you have:

• Confirmed symptoms: misfire, lurching, power loss
• Occurs under load / driving, not just a stored code
• HPFP + LPFP “replaced” by seller (unverified quality/work)
• 500-mile drive before failure → marginal system finally fell below threshold

That combination is textbook EA888 fuel starvation, not a sensor glitch.

Critical clarification (very important)

“I have read about camshaft followers but I’m uncertain if that applies to this motor”

✅ YES — it absolutely applies

Your 2014 Q5 2.0T (EA888 Gen 2) DOES use a cam follower.

Audi quietly improved it over earlier versions, but they did NOT eliminate the wear mechanism. At 118k, it is still one of the highest-risk items on the engine.

Why the seller’s “new pumps” don’t clear it

This is the trap many people fall into:

Scenario that fits your case perfectly

1. Original cam follower is worn/dished
2. HPFP stroke is reduced
3. Seller replaces HPFP + LPFP chasing pressure
4. Pressure is better, but still below spec under load
5. ECU throws P0087 anyway
6. Car feels “okay-ish” until pushed → misfire/lurch

👉 New pumps do NOT fix a worn follower or damaged cam lobe

In fact, a new HPFP on a worn follower accelerates cam damage.

Fuel filter: good move, but…

Replacing the fuel filter is necessary maintenance, and yes, a clogged one can cause P0087 — but:

• A filter alone rarely causes misfire + lurching
• A restricted filter usually causes gradual power fade, not sharp hesitation
• At 118k, the filter is likely a contributor, not the root cause

Think of it as removing one choke point — not the main blockage.

The ONE check that matters most right now

🔴 Pull the HPFP and inspect the cam follower

This is not optional at this point.

What you’re looking for:

• Flat, DLC-coated surface → OK
• Dished center → worn
• Hole or mushrooming → STOP DRIVING (cam inspection)

Why this is urgent If the follower punches through:

• Intake camshaft is usually damaged
• Metal goes into the oil
• Repair cost explodes

This is the fork in the road between:

• $100–600 fix
• $3,000+ engine work

What I strongly suspect (based on everything)

Primary: Worn cam follower ± early cam lobe wear Secondary: Old fuel filter worsening the pressure drop Possible but less likely: Aftermarket HPFP not meeting spec

What I’d do if this were my car

1. Do not drive it hard again
2. Replace fuel filter (since it’s already coming)
3. Pull HPFP the same day
4. Inspect follower before running it further
5. Decide next step based on what you see — not guesses

If you want, I can:

• Tell you exact torque specs & removal order
• Recommend OEM vs aftermarket follower
• Help you identify cam damage visually
• Advise whether the car is still safe to drive short-term

Just say how deep you want to go. This one’s very solvable — but only if you check the right thing now, not later.