I am completely baffled by this problem and I was hoping someone might have some insight. This is the first Volvo I've owned but I work on Volvo trucks for my living. The engines in my company's trucks hold up quite well, I heard many good things about the Volvo 2.5, and I absolutely loved everything about the XC90, so I decided to purchase one. I did a lot of searching and found a used XC90 with 105k miles on it and complete maintenance records. The vehicle was owned by the same people since new and dealer maintained the entire time. The biggest hole I can find in the maintenance records is about 10k miles but the owner explained that some records had been misplaced and a 10k mile hole is nothing to fuss about in my opinion. Anyway, at 119k my check engine light came on for Intake Camshaft Timing Over-advanced. No big deal, I knew I needed to do the timing belt at 120k so I had already purchased it. I replaced the timing belt and fired up the engine with no issues at all. I let it idle until it reached operating temperature and then went to give it a few gentle rev's to get the coolant circulating well so I could top it off (I had also replaced the water pump while I was in there). Upon revving the engine I heard a very clear clicking that sounded like lifter noise. I shut the engine off and re-checked the timing marks and they were all perfect. I fired the engine up again and at idle it was perfectly quiet but as soon as it got above about 2000 rpm I could hear the clicking. I figured I would just drive it gently and the problem would either reveal itself to me or go away.

One day accelerating near my place of employment the "Low Oil Pressure. Please Stop Safely." message came up on the dash, the clicking got louder, and I heard a couple of squeaks. I ran a red light to pull into a parking lot and immediately shut the engine off. I checked the oil which was full, let the car sit for a little while, and then started it up again. The clicking was now there at idle but no messages on the dash or any other sort of noises. I limped it very gently the remaining mile to my place of employment and then called for a tow that afternoon. I was assuming that the O-rings had worn out for the oil sump pick-up tube and dropped the oil pan to investigate. To my horror, instead of some dry and cracked looking O-rings, I found a bunch of metal. The #2 connecting rod bearing had spun. The squeaking I heard was apparently the #2 connecting rod bearing on it's last leg and the lifter noise must have been caused by the oil pressure leaving through that bearing and starving the top end of oil.

I have two questions. First, what on earth would cause a dealer maintained vehicle to spin a connecting rod bearing in an engine that is supposed to be as reliable as the Volvo 2.5T?

Second, how do I split the engine block to remove the crankshaft for repair? I do not have the money to have a dealer or an independent shop make the repair so I am doing it myself. I have removed all of the peripherals from the engine and have just the block, head, and valve cover left in the car as a complete unit. I cannot remove one of the bell-housing bolts because the "angle gear" (trans-axle) is in the way but that bolt is only holding the bottom section of the engine block to the transmission. My plan is to split the upper engine block from the lower engine block so that the valve cover, head, and upper, complete with pistons, comes out of the vehicle and the lower section will stay right where it is. After the two halves are separated I can send the crankshaft out for repair with the offending connecting rod and then put it all back together. I have removed all of the bolts from the underside of the lower engine block and my engine hoist still tries to lift the entire vehicle instead of separating the halves. Looking at a breakdown of the engine I cannot find any reason why it shouldn't be able to come apart while still in the car. Is there some reason the diagram doesn't show that I cannot split the halves while it is in the car? Thank you for your help!