240 smoke under hood - not oil leak

The crankshaft damper pulley is defective. The outer sheave set is a press fit over a rubber sleev to the hub. When they get older the rubber shrinks and the sheaves spin reluctantly over the rubber causing smoke. Once the rubber heats up the whole mess sticks together for a while and then repeats the process over again each time the car sits long enough for the parts to cool. Eventually the sheave section will just fall off and all the lights on the dash will come on. You will lose operation of the water pump, alternator, power steering and air conditioning if equipped. Usually the pulley just falls off toward the motor as the car is moving, however if it falls off during braking it can damage the radiator. I'd get it fixed fairly soon.

Bob

-- The goal when driving is to miss the maximum number of objects.

It happened to our 765T when my wife was tooling around town. Imagine her surprise to see a big chunk of her car rolling into the ditch behind her after the lights came on and the steering got heavy!

Mike

Thanks very much to the two good people who replied. I just looked under my hood again this morning, and I see that coolant is collecting (in a little pool) on top of the case, just behind the fan and below the housing for what I assume is a concealed belt. (Is that the timing belt? Again, I really don't know a thing about car parts.)

So, it's just coolant that blows off the first few minutes of operation. I wonder where the leak source is. I don't think it's a hose. All the hoses to and from the reservoir and radiator are below the coolant "pool." Can I assume the metal engine case above the spot is leaking around some seal of another?? Does this make sense? The car has 260K miles, so nothing would surprise me at this age. If so, can I assume this would be a very expensive repair, as everything must be taken apart.

Thanks again, Volvo people.

Water pump is probably shot. But have the other issue checked out as well since it has the potential to be dangerous.

Aha. The water pump is housed in the same compartment as the timing belt, right? If so, that's just above where the coolant is collecting, I think. Assuming the water pump needs to be replaced, I'm wondering about the labor and parts costs. Does the timing belt need to be removed, or is this a quick and inexpensive procedure (assuming an experienced Volvo mechanic performs the work)?

Since the timing belt should be replaced every 50,000 miles or so, you might as well have it all done at once. The water pump can be replaced without removing the timing belt, but not vice versa. This is pretty standard stuff, any competent mechanic can do it. But the water pump won't be the cause of the smoke that is being seen.