Volvo: 98 S70 T5; Frigid weather: Engine stall under load at start-up, volvo s70 t5, weather max

Question
Hi,
My car:
Volvo S70 T5 (stock turbo)
1998 model year (1997 in-service date)
155,000 miles
Automatic transmission
I only use supreme grade octane exclusively
Factory recommended service always followed very precisely.

On extreme cold mornings (ambient temperature is btw +7 deg F to negative 13 deg F), and I start my car, I let the engine free idle for 30 seconds for oil circulation. After the 30 seconds, with my foot holding on the brake, I gently shift into "D". This has resulted, on some occasions, in an immediate engine stall. (I had to restart, rev slightly above idle and wait another 30 secs to prevent stall when placing back in gear). This has never happened before even though I followed the same exact cold weather start-up routine in the past. Is There A Particular Part That May Have Degraded And Needs Attention?

Please note some other pertinent information:
Problem is intermittent [for example, sometimes at -5 deg F it will happen and sometimes it won't]
The compression is within specs. I had it checked by the Volvo dealer.
The engine ALWAYS delivers a reassuring strong confident engine-start even on those particular days when it stalled after placing in gear.

I drive very gently (rpm below 1800) until engine reaches normal temp in order to warm up engine components. I never allow prolonged free idling at start-up since owner's manual advises against this action in frigid weather (max 30 seconds allowed by owners manual when temp is below 5 deg F). The dealer checked the computer for fault codes and none were present.  Then, he cleaned the throttle body (which appeared clean already) but this did not help since the problem repeated after as well.

Sometimes, in dead cold weather as my car is coming to a halt, (let's say approaching a stop sign), a subtle vibration has alerted me that the engine has dipped to 100rpm below idle (car is still in decelerating forward motion).  The engine then quickly corrects itself (in about 1 to 1.5 secs) and the vibration disappears.

I have oil consumption at rate of 1quart every 1200 miles (but there is never any smoke from the exhaust even at start up).
I have very good mgp numbers. Comparison of readings from the car's digital fuel consumption indicator against my other 2 cars (they are sport sedans as well) have repeatedly shown that the Volvo provides the best mpg even though this car is older and faster than them. The oxygen sensors have never been replaced.

Your input will be appreciated.
Please post this question for everyone; I can't seem to activate the "post on forum" option.

Thanks.
Ghassan  

Answer
Hello! Extreme cold weather can take it toll on many engine components. It seems like you have covered all bases in checking out the car. In my experience, if the car is only acting up in extreme cold conditions I wouldn't worry too much about it. I would just let the car warm up for an extneded period of time.

Jimmy