my vehicle is a 2015 volvo xc 60, with a 2.0T 5cylinder engine and 6speed automatic transmission from asin,the car is made in china , and no chinese mechanics seems to be able to find what's the problem with my car. here s the issue :
when i drive to the speed 40-80 km/h , the rpm starts to shake , not very dramatic,but if i accelerate , the rpm needle will go down ,up , down up a few times, especially when changing gear
i have changed many things, only helped a little but did not solve the problem, heres what i changed :
fuel pressure sensor, spark plugs, ignition coils, fuel injecter cleaned,transmission fluid (oem red oil from toyota),timing belt 3 sets, fuel filter, wastegate(not sure if its the correct name, i use the translator , its the oil leaking value for waste gas)
after i changed all that this issue its still going, especially in gear 3 and 4 it goes up and down a few time before changing gear, i asked some transmission expert, he told me because the car is not shaking during the unstable rpm, it can't be sure is a transmission problem, and i don't have any error code in ecu. this problem is driving me nuts, and i have no idea what goes wrong

this is the shaking rpm, shakes range about 200-400rpm

 

welcome

 

do you feel the engine change speeds and power levels vary or is it just that the tach seems wonky? What happens if you do some hard accelerating (a good way to produce a CEL if you have a fuel or spark issue). If you have a OBD2 reader, you can also see if it will collect run time data to measure fuel trim and O2 sensor cycles.

 

thank you for your reply !the engine while accelerating, the suction does change with the rpm change, when rpm goes up and down, the engine revs going with it.and while hard accelerating, the rpm will go up and down one or two times before gear completely downshift and revs up, it always happene around 3-4 gear.now i think its a transmission issue, but i dont know how to solve it

 

the problem with diagnosing your car is that ignition/fuel mix issues can present similarly to transmission issues (thus my comment on looking at run time data). If you suspect you have some transmission clutch slippage in the higher gears (when the tranny has to handle the most torque) then again you can look for transmission fault codes, higher than normal transmission temperature (your shop may need a more deluxe diagnostics tool like VIDA) etc but I'd also check for other symptoms like shifter flares or hard shifting. Inside your transmission there's two things in play - the clutch disks that transfer power and the solenoids that route the fluid to change the gears. Solenoids usually become a consideration when you have shifting issues (hard shifting, or slow shifts with rpm changes ), You may also hear the term valve body - which is the part of the tranny that the solenoids actuate to move the fluid through the desired path. The valve body can get gunked up which may also lead to shifting issues. When the clutch disks are worn, the usual tell is the fluid. normal tranny fluid is a dark red or almost brownish red. If its black or smells burn, then it means its been overworked or overheated and that is what kills the disks. So if you suspect slippage, You should start by doing a drain/fill using filter paper. If you see little bits come out... well that'd be part of the friction surface from your disks and you have a tranny rebuild in your future. Some people get lucky and just having fresh fluid at the correct level is enough to restore the viscosity to where the transmission behaves again. You can do your own drain fill on the 5 speeds (drain 2 quarts/add 2 quarts about 5 times...) and you can use the dipstick to set the fluid level (there's a warm line). The 6 speeds require a VIDA type tool to properly set the fluid level when the transmission temp is 55C, plus they use a drain tube vs a simple plug. Check out Youtube for some how to vids on doing a transmission drain fill for both an Aisin 5 speed and the 6 speed. With all that said, this may be where you simply understand the complexity of the diagnosis and pay a pro to assess the situation for you.

 

this issue is driving me crazy, i went to 2 transimiion professionist both said my transmission is fine, and i went to the volvo dealership, and volvo dealership told me my car is all fine with no issue, but this is my 4th volvo car and non of other had this problem while shifting gear.