E24 6-Series

1976-1989 / Coupe / Germany

All E24 6-Series problems All workshop issues

Minor Cooling System

9. Cooling System Degradation

Symptoms

Overheating. Coolant leaks from hoses, the expansion tank, or the radiator. The temperature gauge creeps above normal, particularly in traffic or on hot days.

Cause

Every rubber and plastic component in the cooling system degrades with age and heat cycling. The expansion tank becomes brittle and cracks. Rubber hoses harden, crack, and blow off their connections. The original radiator develops internal blockages that reduce cooling capacity. The thermostat sticks closed, preventing coolant flow.

Fix

Replace the entire cooling system proactively: radiator ($300-600), all hoses ($150-300 for the set), expansion tank ($60-100), thermostat ($40-60), and water pump ($120-200).

Total parts cost: $700-1,200.

This is preventive maintenance, not a repair, if you wait for components to fail, you'll overheat the engine and cause far more expensive damage.

Use a brass/copper or aluminium aftermarket radiator for better cooling than the original plastic-tanked unit.

Cost mentioned in fix

$300-600$150-300 for the set$60-100$40-60$120-200cost: $700-1,200

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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