740 / 760

1982-1992 / Sedan / Estate / Sweden

All 740 / 760 problems All workshop issues

Common Engine

Flame Trap Clogging (PCV System)

Symptoms

Rough idle, oil leaks from every seal, oil in the intake tract, sometimes a whistling noise from the crankcase breather.

Cause

The flame trap (a little plastic box under the intake manifold) clogs with oil sludge. This blocks crankcase ventilation, which pressurises the crankcase and blows oil past every seal. Volvo's fancy anti-backfire device becomes an oil-leak generator.

Fix

Remove the intake manifold (easier than it sounds), unscrew the flame trap, and replace it.

Part is cheap.

Clean out the PCV hoses while you're there.

Some people fit an external oil catch can to avoid future issues.

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// More 740 / 760 problems

Other known issues

Critical Engine

Oil Leaks from Cam Seals and Valve Cover Gasket

Oil puddles under the front of the engine, sometimes dripping onto the exhaust manifold and smoking. The valve cover gasket weeps oil down the side of the block.

Critical Engine

Timing Belt Failure

The engine dies instantly, often with a loud slap or clatter. Won't restart. If you're lucky, it just stops; if you're unlucky, bent valves and a destroyed head.

Critical Engine

Oil Consumption (Turbo Models)

Blue smoke on startup or under boost. Oil level drops a quart every 500-1000 miles.

Critical Cooling System

Radiator and Heater Core Leaks

Sweet smell in the cabin, puddles of coolant under the car, overheating, fogged windscreen that won't clear.

Common Cooling System

Expansion Tank Cracking

Coolant level drops, small puddle under the passenger side of the engine bay, sometimes a pressure release hiss.

Critical Cooling System

Thermostat Sticking

Engine takes forever to warm up, heater blows lukewarm air, or (if stuck closed) the engine overheats.

View all 27 740 / 760 problems