Jaguar XK8 Engine Reconditioned, Rebuilt & Used Supply and Fit Across the UK

The Jaguar XK8 uses the AJ-V8 all-aluminium V8 engine family throughout its production run from 1997 to 2006. Earlier models carry the 4.0 litre AJ27 unit, while models from 2003 onwards use the improved 4.2 litre AJ34. Both are naturally aspirated V8 petrol engines the supercharged XKR variant uses the same blocks in boosted form.

Nikasil is a hard, low-friction cylinder bore coating used on early XK8 4.0 litre engines. In the UK, high-sulphur fuel caused the coating to degrade leading to bore wear, compression loss, increased oil consumption, and eventually engine failure. It primarily affects 4.0 litre engines produced before approximately 2001.

Failsafe engine mode is a protective ECU response triggered when the system detects a fault that could cause engine damage. It limits power output and can be triggered by a range of faults from sensors and fuelling issues through to more serious internal problems. Our same-day diagnostics identifies the specific cause before any repair is recommended.

Rebuild costs vary depending on engine variant (4.0 or 4.2), the extent of internal wear, and which components require replacement or machining. A Nikasil-affected 4.0 litre rebuild is typically more involved than a standard 4.2 litre rebuild. We provide fully transparent, itemised quotes before any work begins.

Our complete supply and fit service is based at our workshop . For customers further afield, we offer UK-wide delivery with full technical support. Emergency fitting slots and same-day diagnostics are available for urgent cases.

The XK8 4.0 litre engine typically requires a 10W-30 or 10W-40 fully synthetic oil meeting the relevant Jaguar specification. The 4.2 litre engine generally uses a 5W-30 fully synthetic oil. Always verify against your specific production year and engine number.