First some perspective. This V8 was designed by starting with a Yamaha-designed inboard boat engine, a high-revving V8. As an inboard boat engine, stuff is pretty to get to. Installed as a car engine, not impossible but not so easy.
If you can set aside the time you can DIY the re-seal of the valve covers and timing chain cover without removing the engine,using hand tools and an electric or air impact wrench. The big but manageable headaches are getting the harmonic balancer off-on (tight quarters) and getting the fuel rail off – some fuel hoses are covered in rubber but are actually hard nylon and when people bend them they usually break the Nylon-12 fuel pressure sender mount, which until recently was unobtainable. You can now get replacements from a company that fabricates custom parts for race engines, at a decant price – just search on Amazon or eBay, the are not hiding. TBH the replacements are better than the originals probably owing to the fabricators’ experience on racing engine conditions –they are CNC machining them out of metal and installing brass fittings. One would even consider getting and installing one to replace the original before it breaks, they are that good and that fairly priced. The coil connectors get brittle with age BUT they are 100% the same uses on many toyota, lexus and chevy (yes GM) cars and internally use standard weather-pak bits. I’ve replaced most of mine., while standing in the weather, bent under the hood over the engine, using a $20 knock-weather-pak crimper and a $15 box of replacement terminals and shells I bought over the internet. Because the Denso injectors are also common, you can easily get the filter baskets and o-rings on the aftermarket for short money, too.A fellow from one of the Volvo owner groups published a nice set of instructions for the re-seal job you can download as a .pdf, just do a search for volvo v8 oil leaks or some such, on this site – should find a link to it in the XC90 pages. IF you have a mechanic do this reseal for you it should run into the low 4 figures (USD) because it is time consuming and not because it involves animal sacrifices or unnatural acts, it does not. You can get a kit of ALL the gaskets and consumables needed for the job from FCPEuro for some hundreds of dollars and do it yourself, including cleaning (and painting !!) the valve covers etc over a weekend. (you get wolf tickets if you paint them Volvo Blue!) To slow down the drying-out of the replacement gaskets you can spray those with (also Volvo Blue) Hylomar before install. Granted, a can of spray Hylomar will run you $30 – $40. But there is a reason Rolls-Royce developed the stuff for problematic engine sealing jobs like this one.
The power steering pump is a relatively easy re-seal, various parties sell a kit of FKM orings to replace the original neoprenes for less than $30. The pump itself is quite robust. If you want to go all-out you can replace the bearing while you are in there, when you open it up get the number off it and get a replacement from McMaster Carr or your friendly regional MRO parts jobber.
You will want to have a copy of VIDA 2014D – do a search on this web forum for “VIDA DICE” to see ways to obtain one.
What I would do –
If you are dong most/all the work yourself, and the service records are (pretty) complete, I would go for it but be prepared for learning curve. It will not be cheap to own. It’s not too bad once you figure out global sources for parts and the why-and-how of the Ford platform (EUCD) the car is built on in the first place. Posts in this forum were helpful (I have a 2009 S80 V8) and youtube videos (for instance those posted by VolvoSweden) also helpful however, watch out because there are some instructional posted by people obviously suffering from cranaial-rectal inversion. Insights I gained from working on a Lincoln and a Mercury (Ford) I used to own (same engine control strategy, different parts) were a make-and-break thing for me initially, mine did not run right when I got it because PO’s mechanic, a good buy, could not figure out how to actually fix a random misfire the car had. And the service information did not anticipate this problem ** except ** for some reason Volvo-Ford put a detailed technical description of how the ignition functions in the service manual narrative. Based on that I deduced what was wrong, had to do with a dissimilar metals situation introducing a capacitance that actually filtered a signal the ECU needed to adjust engine timing. Once eliminating that situation with conductive grease, the problem was solved and has stayed solved for 2+ years. Your problem is that given the other stuff going on with this Volvo variant, not many people are going to figure that kind of situation out on this car, period.
If you have kinda deep pockets and a good independent mechanic who’s worked on Volvo-Ford-LandRover cars on this EUCD platform, you’ll likely be fine although they may not have the same gusto for finding parts as you the owner; that can be a sore issue. And in any event it will likely be expensive.
If you are not planning to do the work yourself and have no independent Volvo mechanic, it’s a Hard Pass. The cars are old enough that (1) even in the dealer network, service is an issue and (2) unless you’re using used and aftermarket parts the cars are not really possible to maintain due to obsolescence of factory parts – when the variant turned 10 y.o. in the USA, Volvo killed many of the unique V8 parts – gives a new meaning to the term, “rarity.” For instance, when it comes time to work on the CV joints you will likely want to remove them and replace just the joints unless you can get high quality reman axles. You can obtain good SKF and other joints from Europe. You will want (need) an aftermarket screw-press version of a Ford tool to replace front wheel bearings and another to replace rear trailing arm bushings. There’s another tool to rebuild the rear diff (get it via Land Rover actually). No kidding you may run into substantial trouble getting proper repair work done.
Good luck.
Best,
Albertj