Dear Brickboard Readers and Members,

Re: 1990 745T auto

My car's engine suddenly started losing power on the highway at about 60 m.p.h. during a mild passing maneuver about 50 driving miles ago. Since then I have noticed the following pattern:

Normal starting. Normal drivability to about 25 mi. per hour. Big loss of power from about 25- 30 mph upwards. Engine sounded yesterday on the highway like it was missing or misfiring upwards of 25-30 mph.

The car can make it up to 55-60 mph despite the loss of power, but it takes a couple of minutes to get going that fast and the transmission keeps the car in third gear at that speed. I can get the transmission to shift up into fourth gear by taking my foot off of the gas pedal, but when the car starts slowing down and I give even a little gas again, the transmission shifts back down into third right away.

Exhaust does not seem particularly smoky, but highway gas mileage seems to have dropped to about 60 percent of normal. Motor oil level and condition both seem fine. At a standstill with the shift lever in Park or Neutral, the motor revs up to near redline with no problem.

I am still looking through the Forum, Maintenance Tips page and posts but have not found anything yet or maybe overlooked something.

What makes it unusual - for my lay knowledge - is that the car is acting normally in town at low speeds but seems like it's not developing much any power anymore for highway driving. This is a sudden development since yesterday afternoon.

The car is a 1990 740 Turbo wagon with automatic transmission. The car has 173,000 mi. on it, I have power flushed the transmission fluid two or three times so far since my acquisition at about 75,000 mi.

Thank you for reading this and thank any of you in advance if anyone can shed light on this. I am continuing to look through the Brickboard and am also pursuing local expertise.

Paul Scesniak
Beaver Dam, Wisconsin