Parts for your 1998 Subaru Forester-Crank angle sensor

1998 Subaru Forester crank-angle-sensor (crankshaft position sensor)

Technical sources confirm the 1998 Subaru Forester is fitted with a crank-angle-sensor, more commonly called a crankshaft position (CKP) sensor by Subaru. The 1998 Forester Factory Service Manual details the CKP signal as a primary engine timing input for the ECU, and Subaru parts catalogues list the CKP sensor (e.g., EJ20/EJ25 engines, typical PN family 22056AA0xx). Independent manuals for the era, such as Haynes/Gregory’s for Forester/Legacy/Impreza, also specify CKP testing and replacement procedures for 1997–2002 models.

On this SF-series Forester, the crank-angle-sensor sits at the front of the engine facing the crankshaft timing sprocket. It reads a toothed reluctor and tells the ECU exactly where the crank is in its rotation. That timing data runs the show: spark delivery, injector timing, and fuel/air strategy. If the CKP signal goes missing or messy, the ECU can’t confidently fire the engine, and it’ll either refuse to start or run poorly.

For routine servicing, the sensor itself isn’t a scheduled replacement item, but it’s smart to keep an eye on its connector and harness. Heat, oil weep, and vibration can harden the loom and cause intermittent faults. During major services (timing belt intervals, cooling system work, or front-end accessories off), it’s a good moment to visually check the sensor body for damage and ensure the plug is clean and snug. A quick squiz for corrosion and a gentle clean of the connector pins with appropriate electrical cleaner goes a long way. There’s no user-set “gap” on this setup—the mounting is fixed—so if it’s damaged or readings are out of spec per the factory manual, replacement is the go.

Common red flags that point at the crank-angle-sensor include:

• Cranks but won’t start, especially when hot, then starts again once cooled.
• Intermittent stall with no spark and a dead tacho, then sudden recovery.
• OBD-II fault codes like P0335/P0336, plus rough running or misfire feel.

Diagnosis first: scan for codes, check live RPM while cranking, inspect the wiring, and confirm the timing belt condition and alignment. If the sensor’s the culprit, replacement is straightforward: isolate the battery, access the sensor at the front of the engine near the timing cover, remove the retaining bolt, swap in an OEM-quality unit, route the loom correctly, and torque to factory spec. After fitting, clear codes and verify stable RPM signal and clean starts. Using a genuine or reputable brand sensor keeps the Forester happy for many more kilometres.

Popular questions

What are the symptoms of a failing crank-angle-sensor on a 1998 Forester?

Typical signs include cranking with no start, random stalling, a dead or jumpy tachometer, and fault codes like P0335/P0336. Some owners notice the issue more when the engine is hot, with normal behaviour returning once it cools. Fuel economy and drivability can also go off if the signal is weak or erratic.

Can a dodgy crank-angle-sensor damage the engine?

Not directly. The ECU will usually shut down spark/fuel if it can’t trust the signal, so it’s more of a no-start or stall scenario than a mechanical risk. The bigger trap is misdiagnosis—similar symptoms can come from timing belt issues or wiring faults, so a proper check is essential.

Should the crank-angle-sensor and cam sensor be replaced together?

They’re separate parts doing different jobs. There’s no rule to replace both unless diagnostics point to faults in each. Many mechanics replace only the failed sensor, then confirm clean signals from both CKP and cam sensors with a scan tool and road test.