Sorry this is so long I just want to make sure you have as much info as possible. I’m working on a 2006 Volvo XC90 2.5T AWD. Here’s the problem and what I have done to fix it so far. It started with the dreaded “NO OIL PRESSURE-safely stop the vehicle immediately “ Which I did and checked the oil which was 1/2 qt low and the engine sounded fine, no clattering or clanging or other no oil engine noises. I was only a few miles from home so I stated her up again to take her home and she sounded fine. The error message popped on and off maybe twice on the 10 minute ride home. I topped off the oil and called it good but the next day i drover around locally for an hour or so and the message popped up again and again the engine sounded fine but I took her home immediately (again I was only a few miles from home) and looked up the possible causes which you all know. So I started with the easiest, I dropped the sump replaced all the O-rings, cleaned the pickup tube and the sump, changed the filter and filled with new 10W-30 full synthetic. The error message popped up again a day later. So next I did the glove test, it failed so I replaced the PCV/ oil trap system and cleaned everything that needed to be cleaned as per the instructions (man what a pain in the A**) and while I was there I also replaced the oil pressure sensor. When it was done I did the glove test again and it passed with flying colors. Couple days later my girlfriend took the car out to run some errands after an hour or so the message popped up AGAIN! DAMN! After looking on line for possible causes I dropped the sump again replaced the O-rings again only this time with genuine Volvo parts cleaned the pickup tube (it looked clean but I did it anyway) cleaned the sump (there was about a teaspoon maybe a tablespoon of crud in there) changed the filter (there was a small amount of crud on it) and put it back together. It was really hot outside so I waited a day or so to put it back together so every last drop of oil drained out of the engine. Anyway I filled it with 5W-40 full synthetic and called it good. I went to start it up and it was making this loud horrible screeching noise from the drivers side of the engine compartment (at least I think its coming from the drivers side) its kind of hard to tell. I immediately shut her down and checked the oil level and it was perfect. The noise sounds kind of like a slipping drive belt only its coming from the wrong side. I started her up again a couple times and let it run for a few seconds to try and ascertain the problem to no avail. I needed to move the car from the driveway about 10 or so yards away so I started her up once more and moved the car which went just fine no problems accept for the noise. The engine sounds fine and smooth and she starts right up no problem…any ideas?

 

For the oil pressure light - change the oil pickup to the new style "tulip" shaped pickup tube.

Don't know about the squeal - but more than likely has to do with something you touched. When it's making the noise pull the dipstick. If the noise goes away there is too much vacuum in the crankcase - if so something is wrong with the PCV system that was just touched. Maybe the metered orifice banjo bolt came apart.

 

Bought the car used from a private party about a year ago and it already had the tulip style pickup tube. Removed oil stick and it did not affect anything. Didn't touch anything accept what you would normally touch dropping the sump and reinstalling it. All my tools were accounted for. It's a mystery for sure. I'm paranoid to leave it running for any length of time for fear of doing serious damage to the engine, but honestly i don't think the noise is coming from the engine it self. In fact i'm 90% sure it isn't. Turbo maybe? BUT- if so, why? it was running fine before and all i did was drop the sump change the O-rings, installed new filter, reinstalled the sump and put in new oil...that's it. don't see how the turbo could go **** up just sitting there.

 

Have you checked the oil pump?

 

Hello All, Thought I’d give an update on my problem and how I solved it just in case someone else encounters the same issue. So it turns out I had over tightened the two 13mm bolts that bolt the sump to the transmission. Who knew those pesky torque figures are actually important and not just a suggestion. Anyway I really tightened those suckers down because they seemed a little lose when I removed them. As a result the over tightening of those two bolts warped the transmission case enough for the flex plate to rub the inside of the tranny case and one of the bolts that hold the sump to the block. As soon as I loosened them the screeching noise went away and she purred like a kitten. So there ya go, lesson learned…always pay attention to the torque specs- their important.

 

Does anyone know where I can get step by step instructions' on replacing the turbo on my 2006 xc90 2.5t AWD. I've spent the last week off and on trying to find work ups and/or videos on the subject but I can't find anything worth a s**t. I'm confident I could figure it out but that's doing it the hard way. There's always tricks to any job. So if anyone can steer me in the right direction I'd really appreciate it. Thanks