Dear Boris,

Hope you're well. Yes! Volvo VADIS - the superseded dealer parts/service database - shows that the B230FT engine used in the '92 940 Turbo indeed has a crankcase ventilation system.

This consists of a flame trap and an "oil trap" (breather box). If not clogged, this system allows any crankcase over-pressure to be vented, with oil fumes being pulled into the intake manifold, and thence into the engine, where those fumes are burned.

As engines age, combustion gases can get by the piston rings, and add to pressure normally present in the crankcase. So long as the crankcase ventilation system is clear of obstructions, this over-pressure does no damage.

If the crankcase ventilation system is clogged, the over-pressure can force oil past seals (crankshaft [front or rear] or camshaft) or even displace the seals, creating major oil leaks.

The flame trap - a white plastic fitting - is housed between the third and fourth intake manifold runners (arms). The oil breather box is mounted below the flame trap. It can be removed without first removing the intake manifold, if the idle air control valve is removed.

Hope this helps.

Yours faithfully,

Spook