2001 Volvo S40 1.9T

Fully opening the throttle from a slow speed (seems like 1st gear) gives what feels like very little torque (no wheel spin) and a rattling or knocking noise coming from the engine or transmission (hard to pin point). Does not do it while in manual. Usually around 3.5-5k rpm. I use 91 octane.

Also when cold starting the service light stays on for about 10 minutes and during this time the car sometimes idles at a higher rpm then usual around 1k rather then the usual 500-600.


Any ideas?

 

Also, tranny seems to struggle catching the next gear, feels jerky.

 

Possible problems.First you really need to fill with the highest octane avail in your area usually its 93.Then your transmission probably need new oil if ever been replaced.Use Mobil 3309 from here:
Mobil ATF 3309 Case of 12 quarts
Then the knocking noise on load could be your driver side axle and or the engine supports.Also had knocking noise by a lose waste gate arm which also made me lose some power too.Let us know if the oil in transmission ever been replaced and when.What is the millage on the car.

 

158k clicks on it. I purchased it used at 157k have no records on any transmission oil changes or any other work.

Is a tranny oil change something that can be done out of the shop?

 

Yes there is a procedure to follow if you are mechanically inclined you can do
it home.I myself just had it done in a shop in an hour bringing my own oil.I just find it way easier tho Im a mechanic myself
Had only 50K in the oil but I dont care what volvo claims that the oil need no change for the life of the car but it was black and smelly.
It would help if you could pinpoint the origin of the noise.Does it sound like it coming from one side or the middle perhaps?