XJ6 (Series I-III)

1968-1992 / Sedan / United Kingdom

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

Common Engine

SU carburettor problems (Series 1)

Symptoms

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

Cause

The twin SU HD6 or HD8 carburettors need regular maintenance, jet needles wear, diaphragms split, float valves stick, and the mixture goes rich or lean. Most mechanics don't understand SUs and make things worse.

Fix

Strip, clean, and rebuild both carburettors.

Replace needles, jets, diaphragms, and float valves.

Set float heights.

Synchronise with a proper flow meter.

Budget $400-800 AUD for rebuild kits and a few hours of patient work.

Cost mentioned in fix

Budget $400-800

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// More XJ6 (Series I-III) problems

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

Cooling system inadequacy

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

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