Known-good values
Known-good values by engine
What does a healthy engine read? Mechanics report live data and measurements from cars that run correctly, and each engine page shows the median and the normal range, next to our typical guide. No more guessing from forum posts with numbers that contradict each other.
How it works
- After a confirmed repair, or on a healthy car, add at least three values from live data or your measurements.
- Each member counts once per engine (your latest readings). The median appears from 3 members up, with the middle half of the readings as the range, so one odd reading cannot pull it.
- Only totals are shown, never who reported what. The admin can hide readings that are clearly wrong.
Engines
VW Group 1.9 TDI PD (Pumpe-Düse)Diesel · 1998–2010 · no readings yetVW Group 2.0 TDI common rail (EA189)Diesel · 2008–2015 · no readings yetVW Group 1.6 TDI common rail (EA189)Diesel · 2009–2015 · no readings yetBMW N47 2.0 and 1.6 dieselDiesel · 2007–2018 · no readings yetRenault/Nissan 1.5 dCi (K9K)Diesel · 2001–2021 · no readings yetPSA/Ford 1.6 HDi and 1.6 TDCi (DV6)Diesel · 2004–2018 · no readings yetFiat/Opel/Suzuki 1.3 Multijet, CDTI and DDiSDiesel · 2003–2018 · no readings yetMercedes-Benz OM651 2.1 and 1.8 CDIDiesel · 2008–2019 · no readings yetToyota 2.0 and 2.2 D-4D (1AD, 2AD)Diesel · 2005–2015 · no readings yetMazda 2.2 diesel (MZR-CD and Skyactiv-D)Diesel · 2008–2022 · no readings yetVW Group 1.2 and 1.4 TSI (EA111, timing chain)Petrol · 2006–2015 · no readings yetVW Group 1.8 and 2.0 TSI/TFSI (EA888, generations 1 and 2)Petrol · 2007–2013 · no readings yetPSA/Stellantis 1.0 and 1.2 PureTech (EB)Petrol · 2012–2023 · no readings yetFord 1.0 EcoBoost (three-cylinder)Petrol · 2012–2022 · no readings yetBMW/PSA 1.6 THP and VTi "Prince" (N14, N18, EP6)Petrol · 2006–2018 · no readings yetRenault/Nissan 1.2 TCe and DIG-T (H5Ft, HRA2DDT)Petrol · 2012–2018 · no readings yetHyundai/Kia 2.0 and 2.4 Theta IIPetrol · 2009–2019 · no readings yetFiat 1.4 MultiAir and 0.9 TwinAirPetrol · 2009–2020 · no readings yetVolvo 5-cylinder petrol (2.0–2.5, turbo and non-turbo)Petrol · 1997–2016 · no readings yetHyundai/Kia 1.6 GDI (Gamma)Petrol · 2010–2019 · no readings yetToyota/Lexus 1.8 Hybrid (2ZR-FXE)Petrol · 2009–2022 · no readings yet
What you can report, and the typical guide
| Value | Engines | Typical guide |
|---|---|---|
| Engine | ||
| Idle speed, warm (rpm) | Petrol and diesel | Usually about 650–900 rpm |
| Coolant temperature, fully warm (°C) | Petrol and diesel | About 85–105 °C |
| Oil pressure, hot idle (bar) | Petrol and diesel | Typically above about 1.0 bar |
| Oil pressure, hot, 2,000 rpm (bar) | Petrol and diesel | Typically above about 2.5 bar |
| Compression, typical cylinder (bar) | Petrol and diesel | Petrol about 11–15 bar, diesel about 25–35 bar |
| Air and fuel | ||
| Air mass, warm idle (g/s) | Petrol and diesel | Petrol: roughly 1 g/s per litre of engine size |
| Air mass, warm idle (as mg per stroke) (mg/stroke) | Diesel | Compare with specified in live data; changes with EGR |
| Total fuel trim, warm idle (%) | Petrol | Within about ±10 % |
| Total fuel trim, 2,500 rpm (%) | Petrol | Within about ±10 % |
| Manifold pressure, warm idle (kPa) | Petrol | Naturally aspirated: about 25–40 kPa |
| Boost at full load (absolute) (mbar) | Petrol and diesel | Turbo engines: compare with specified boost |
| Fuel system | ||
| Injector pulse width, warm idle (ms) | Petrol | Port injection: often about 2–4 ms |
| Fuel pressure, low-pressure side, idle (bar) | Petrol and diesel | Check the specification for the system |
| Rail pressure, warm idle (bar) | Petrol and diesel | Diesel common rail: typically about 250–400 bar |
| Rail pressure while cranking (bar) | Diesel | Typically past about 200–300 bar within 1–2 s |
| Largest injector correction, warm idle (mg/stroke) | Diesel | Typically within about ±2–3 mg per stroke |
| Emissions | ||
| Particulate filter differential pressure, warm idle (mbar) | Diesel | Low on a clean filter; compare with the reading at 2,500 rpm |
| Electrical | ||
| Charging voltage, 2,000 rpm (V) | Petrol and diesel | About 13.8–14.7 V |
| Lowest battery voltage while cranking (V) | Petrol and diesel | Above about 9.6 V |
| Crankshaft sensor resistance (inductive type) (Ω) | Petrol and diesel | About 200–2,000 Ω |
| Injector resistance (petrol port injection) (Ω) | Petrol | High-impedance: about 11–18 Ω |
The guide is ipacen's typical range, not manufacturer data. Always compare with the specification for the engine.