I have a 2000 S40 with automatic transmission and the 1.9T. It has 141,000 miles on it and ran great until this problem.
I recently have a shuddering when the car has been driven for about 10 miles. It started after I had sprayed the engine off at a car wash trying to be careful not to get the wrong things wet. Car has the check engine light on and it normally comes on in the winter and goes out when the weather gets warmer. It is staying on this time though. It kind of shudders and loses power driving from 60-75 mph. It only dose it when the car is at highway speeds and after the care has been driven at highway speeds for more than 10 mins. It is fine once I get off the highway and in traffic.
If I give it more throttle it just shakes violently until I lift off the throttle and it goes away. It only happens when the motor is under load. Seems the longer you drive the car it goes away.
I have changed the plugs with no help and also bought a new coil and switched from the 3-4 cylinder with no change. I have tried changing gas also with no help.
I have been hit bad with the economy and can not afford to take to a shop for repair so I need your help in a bad way. I need to be able repair myself if possible.
Would you think I should try another coil to eliminate that completely before moving on?
Remember it drives fine in the city stop and go and just dose it after being driven at highway speeds for at least 10mins or 10 miles.
Thanks In advance for any help.