Hi, I will appreciate if I can have some help from this forum.

My XC90 220000 KM On it started to surge. While Idle when I accelerate which is not smooth, but when I reached over 80 KM it becomes smooth.

First I thought there must be some head gasket problem because when I changed spark plugs year ago I saw oil around plugs. But now when I checked the plugs they are pretty clean, then I changed the coils but no difference. By the way when I disconnect coil 5,4,3 left to right no difference but when I disconnect 1,2 it does shakes.

Now my next suspect is injectors, Pressure test and Turbo Boost Valve.

what can be the culprit? please advise.

 

Engine size would help. It could be a number of things. Is the check engine light on at all?

 

Yep, engine light is on. And its 2.5T. 5 Cylinders.

 

Did you pull the code? Knowing the code number would be a good place to start...

 

yeah checking the check engine codes is 1000 times more accurate than people guessing over the internet.