E24 6-Series

1976-1989 / Coupe / Germany

All E24 6-Series problems All workshop issues

Critical Engine, M88 (M635CSi)

8. Valve Clearance Drift

Symptoms

Ticking from the top end of the engine, particularly when warm. Loss of power in the affected cylinders. In severe cases, exhaust valves burn from insufficient clearance (running too tight).

Cause

The M88 uses bucket-and-shim valve adjustment. Unlike hydraulic lifters, the clearances change as the valve seats wear and the shims bed in. BMW specified checking every 20,000 km, which many owners defer.

Fix

Valve clearance check and shim replacement.

The camshafts must be removed to access the shims.

This requires specialist tooling and knowledge, do not attempt this on a roadside.

Cost: $400-600 at an M-car specialist.

Shims are available from BMW (part numbers vary by thickness, $10-20 each) and aftermarket suppliers.

Cost mentioned in fix

Cost: $400-600$10-20 each

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// More E24 6-Series problems

Other known issues

Minor Structural and Body

1. Front Subframe Mount Corrosion

The front subframe mounting points corrode from road spray and accumulated grime. In advanced cases, the mount tears away from the body under braking or over bumps, causing a complete loss of front suspension geometry.

Minor Structural and Body

2. Rear Trailing Arm Pickup Point Corrosion

The rear trailing arm mounting points weaken from corrosion, causing the rear suspension to shift under load. Symptoms include vague rear-end handling, uneven rear tyre wear, and clunking from the rear when cornering.

Critical Structural and Body

3. Windscreen Surround Corrosion

Bubbling paint around the windscreen edges, particularly at the lower corners. By the time paint is bubbling, the underlying metal is often perforated.

Common Structural and Body

4. Door Bottom Corrosion

The lower edges of the doors develop rust bubbles. In advanced cases, the door skin perforates. Paint appears to blister from the inside out.

Critical Engine, M30 (633CSi, 635CSi)

5. Timing Chain and Tensioner Wear

Rattling noise from the front of the engine on cold start, lasting 2-10 seconds until oil pressure builds. In severe cases, the rattle persists when warm. If the chain jumps teeth, the engine timing shifts and performance drops dramatically, in worst cases, valve-to-piston contact occurs.

Common Engine, M30 (633CSi, 635CSi)

6. Bosch L-Jetronic Fuel Injection Issues (Early 633CSi)

Rough idle, hesitation on acceleration, rich or lean running, poor fuel economy. The engine may start fine cold but run poorly once warm, or vice versa.

View all 15 E24 6-Series problems