Engine Noise While Accelerating
 

Hey guys I am the owner of a 2006 Volvo S60 2.5T with almost 152 k miles on it. Recently while driving my Volvo I have started hearing a screeching noise when I started the car up in the winter months. At first it was a very loud screech but after a few minutes the noise went back to normal. However, when driving the car and trying to accelerate up to higher speeds, there seems to be constant ticking noise that seems to fluctuate with the number of RPM's the engine is going at. The lower the RPM's, the slower the ticking noise and vice versa with higher RPM's. I have done some research on the causes that could be ranging from failed O-rings to a bad turbo. Does anyone have an idea of what the problem could possibly be and how to fix it?

Safe to drive?
 

So assuming same high pitch symptom, and pulling dipstick temporarily resolves, leading to reasonable belief that I have the same issue with my 2015 XC90, 67k miles... is it safe to drive (or risk of further damage or breakdown) 10 miles to the dealer? 150 miles round trip, for a trip this weekend?
Dealer cannot schedule time until next week...

”asking for a friend” thanks for any feedback

Engine tick is something you want to get looked at asap. You wait too long and you'll lock up your engine. I had an old beater that developed a tick and i just rode it until it died, lasted a few months. Couldn't even turn the engine by hand anymore after it stalled at a stop. Get that ticking noise looked at, could be many things. older volvos do have lifter noise which you may be hearing, not sure but it wont be related to the screeching. If you add a little more oil ( dont overfill) the lifter noise will quiet down.

EDIT: I do not hear my lifters when im driving though, only heard outside the car at idle

You probably have a PCV issue. Do the glove test on your oil fill. Put a medical glove over the fill with the cap off and car running, if glove inflates, you have a buildup of manifold pressure and the PCV system is needed to be serviced. If the glove gets sucked in, PCV is good.