Warning, LONG POST FOLLOWS:

I have done my homework by reviewing the FAQ's. Some of them are helpful, but I think my problem is not covered.

Here are the symptoms and my analysis. Please, give me your opinion.

So many small things and no idea of what is related to what. The car is a 1994 940 turbo wagon with 200k miles. I do about 2000 miles yearly. Generally the car runs well and it has been maintained. I have replaced the cooling hoses at the bottom in front of the transmission and I have cleaned the air intake valve, both within the past couple years. The RPMs are usually at 600 and steady, except when they drop to nothing. Warm weather seems to be the cause, by warm I mean 50 degrees and above, but that’s one of the problems.

Last summer (warm weather) after the car was warmed up the RPMs would drop to near zero and sometimes the car would stall. With colder weather in the fall, things improved. But, when the weather warmed up as it does from time to time, even during the winter (Boston) the low RPMs and stalling would return.

A couple years ago, with an inexperienced teenager at the helm, the car was cooked a bit, when the radiator lost water. I monitored the engine by examining the exhaust and decided, without anything more objective than that observation, the head and/or head gasket had altered in some way allowing coolant to enter one or more cylinders. This was guess work based on very limited information.

A clever friend advised trying pepper and I added 3 tablespoons to the coolant reservoir with what seemed to be improved results that is, not skipping on start up. This is important because of what I have been experiencing lately.

In this very cold season, some mornings the car will start, but skip badly for the first 20 seconds. About once a week, particularly when it is very cold, the car won’t start at all - at first - but after several tries and a rest period of 5 minutes it will. Then it skips so much that there is not enough power to drive up hill (my driveway). After a half minute of running it seems to “kick” into its usual even running mode with no skipping. And if its cold weather, the RPMs maintain at 600. There is no problem until the next time it happens again when left over night. Sometimes, after a cold night it doesn’t skip, which leads me to think the problem is related to the position of the valves and/or pistons when the car is shut down. All of this makes me think water/Coolant in the cylinders.

The following may be unrelated, but worth mentioning:

1) Occasionally, the fan continues to run after the engine is shut off. I am familiar with cars in which this happens by design, but never before in my experience with 240, 740, 940. If I turn the ignition on and off again, it usually stops the fan, but sometimes, I have to do it several times. If I leave the car with the fan running it shuts off by itself. I don't find it running when I return.

2) Sometimes and this is, again, intermittent, I’ll be driving along with the heater on and suddenly the air will change to cool as if I have turned the thermostat down all the way. This will continue for a few minutes and then correct itself and things will be fine. It almost seems as if the correction occurs as a result of cornering, but that is just a foolish supposition on my part. I have recently replaced the hoses that go to the heater core at the engine fire wall and I was careful to install the valve correctly.

3) When I check the coolant … and this may be significant to the head gasket/leak theory … the coolant level seems to drop slowly, but there is no indication under the car of any coolant escaping. I know what that looks like and I would notice it. But the level does drop over the course of a week or two, so that I have to add ½ quart. This supports the theory that coolant is getting into the engine and burning off. It doesn’t explain why the car continues to run so smoothly once the initial skipping has passed. Maybe these Volvos are so good, they run well on anti freeze.

I haven’t tried another dose of pepper, but I think that would be the easiest and next step. If the problem abates, it will tend to support the coolant in the engine hypothesis. Otherwise, the car is just about perfect, meaning everything works, no dents, no cracked tail or parking lights, etc. etc., intact grill. With limited knowledge I tend to address issues as they arise, rather than being aggressively pro-active. I have done some significant work, over the years, but a motor job, meaning a head gasket is not on the list of things I am prepared to attempt, at least not while it is 10 degrees out, and probably not when it is 50 or 100, either.

Anecdotal story: For several years I stopped at my mother’s house every other day in the winter to hand feed her steam boiler, that couldn’t seem to hold its water. I disparaged the suggestion of adding a liquid sealant, thinking this was just hog wash. A few weeks ago, I figured I had nothing to lose by trying it, other than $20 for the liquid sealer. I added the sealer. The problem now seems to have stopped. This made a believer out of me and in the case of the 940, pepper might do the same thing.

What do you think? Could the skipping be something else, like an injector. I have added some dry gas recently. Frozen water in a cylinder seems to me like the best guess. (Right, if it is coolant, it won't be frozen!) Trying to start the car eventually breaks the ice down, or mixes it with the fuel enough so that after a while it fires. It then takes 1/2 minute to work the dilute mixture out of the engine.