Engine sound.

[Anubisxc70]

2004 XC70 D5 awd.

I know sounds and clunks are always a pain to sort out. But here it goes maybe you guys have some idea.

4 weeks ago, my intercooler, radiator, egr valve, and Maf were changed. From this changes two things came up. First was smoke, that was caused by a defected MAF, the old went in and it seems it solved the problem.

The second change is, noise inside the cabin, the car became more noisy especially between 1500 and 2200 (i think) when it pulls its really loud. Now the strange parts. Its not every time, and usually the noise decreases with temperature i guess, after being running for an hour or so the noise seems to reduce.

I have checked the exhaust for leaks, the only i couldn't see very well was the flexible, i could find none. I have checked the fire wall , the seal from the steering wheel, all is fine there. I didn't see nothing against the body so it could cause an eco.

Vida tells my car has 3 codes. Air quality sensor, radio is missing, and cruise control not working...but it does. So none related for the engine to make that sound.

I guess the parts i have changed...could not cause the sound, strangely that it got louder since they were changed.
The car pulls like it never did at higher rpm on cruise its silent unless of course a hard pull is made.

I know i can buy soundproof material and make it better, but i would like to know your opinions about it.

Many Thanks...................once again