XJ6 (Series I-III)

1968-1992 / Sedan / United Kingdom

All XJ6 (Series I-III) problems All workshop issues

Common Engine

Cooling system inadequacy

Symptoms

Engine runs hot, particularly in traffic or on warm days. Temperature gauge climbs, coolant may boil over, heater blows hot when it shouldn't.

Cause

The XK engine was designed when cars moved constantly and relied on airflow for cooling. In modern stop-start traffic, the cooling system is marginal. Radiators clog with scale, thermostats fail, water pumps lose efficiency, and fan belts slip. Australian heat makes everything worse.

Fix

Comprehensive cooling system service: flush and recore (or replace) the radiator, new thermostat, new water pump if weak, check fan belt tension, and consider an electric fan upgrade.

Fresh coolant (50/50 mix, not straight water).

Budget $1,000-2,500 AUD for a thorough cooling system overhaul.

Cost mentioned in fix

Budget $1,000-2,500

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Other known issues

Common Engine

XK engine oil leaks

Oil weeps from cam covers, timing chain cover, sump gasket, and rear main seal. The engine bay is perpetually oily. Oil drips on the exhaust and creates smoke.

Common Engine

SU carburettor problems (Series 1)

Rough idle, flat spots, hesitation, black smoke, fuel smell, poor starting.

Common Engine

Fuel injection issues (Series 2 and 3)

Hard starting, rough idle, hesitation, stalling, poor economy.

Minor Engine

Head gasket failure

Coolant loss, white smoke from exhaust, overheating, mayonnaise under the oil filler cap.

Minor Engine

2.8-litre engine problems

Excessive vibration, bearing failure, overheating, poor performance.

Minor Bodywork and Rust

Sill corrosion (structural)

Outer sills bubble and perforate. Inner sills rot silently behind trim. The car's rigidity decreases, doors sag, gaps become uneven, and the body flexes over bumps.

View all 28 XJ6 (Series I-III) problems