❗❗ The single biggest cause of issues with XC90s and 3.2 engines is delayed maintenance. Do it earlier rather than later.
- Here is a general video about the 3.2 (& P3 3.0 T6) maintenance guide. Note, the suggested maintenance schedule and intervals are posted below in the table based on real-world feedback from 3.2 owners and can differ from this video. FCP 3.2 diagnostic & maintenance guide
- ⭐ Here is an online resource for factory (VIDA) documents, and repair guides. (scroll to the bottom for the XC90 versions): Free Online Volvo factory repair guides seen in VIDA (may have to use an ad blocker, click outside of the pop-up screen)
I realize now that most of my work is not on the 3.2 engine in my XC90. It has been a bulletproof 6cyl with good oil changes and maintenance. From my experience, here in this post is what I suggest for the 3.2 engine, regardless of year.
Volvo 3.2 SI6 engine: B6324S | Oil Consumption – Engine info
❗ (May 2023) Note: Many 3.2 owners report having serpentine and cooling parts fail between 105k-135k miles. That means before complete failure, major wear and age were building up, such as having a wobbly pulley or some seeping coolant. There are also reports of the A/C compressor getting damaged due to delayed serpentine work.
Scheduled Service (New)
I am adding this table to help with the scheduled service for the 3.2 engine. Thanks to posts on SwedeSpeed, 3.2 owners have shown the Volvo/dealership recommended service intervals to be too long. The shorter intervals are listed based on owners’ experiences with repairs. Explanations, links, and videos are provided after the table.
Hint: Do the service earlier and if the time comes to change these items again, use the FCP lifetime replacement warranty.
| Part/Service | Volvo recommendation (miles) | Repair schedule and interval based on Owners’ experience (miles) |
|---|---|---|
| Serpentine Belt Service | 150,000 | 100,000 |
| Cooling System | 150,000 | 100,000 |
| Decoupler (A/C side) | 150,000 | 100,000 |
| Alternator | When there is an issue with charging | When there is an issue, but the decoupler bolted to the alternator can seize. If you have the alternator out, or have access, check the decoupler and gear/pulley bolt. Should have been checked by 130k-150k miles, but if this alternator decoupler seizes, it could potentially cause the drive gear bolt to loosen. |
| Oil and Oil change interval | 7,500 mile interval, 5W-30, 0W-30 Euro Castrol (A3/B3) | 5,000 mile interval, 0W-40 oil (A3/B3, A3/B4) |
| Engine mounts | when it breaks | 100,000 |
| PCV | when you hear a whistle | 100,000-120,000 |
| Spark Plugs | ~65,000-70,000 | 50,000 |
| Ignition Coils | when they leave you stranded | 150,000 |
| Brake vacuum pump seal/o-ring kit | when it leaks oil | 75,000-125,000, if you have over 125k miles install the seal/o-ring kit before it leaks oil |
| Fuel pressure sensor | when you get a code and engine runs rough | 100,000-120,000 |
| Fuel system & injector cleaning | may upsell as part of major service | –Fuel filter every 100,000 -Use a good modern fuel system cleaner once every other oil change since these 3.2s are older. Some owners do it before each oil change. |
| Transmission fluid | Volvo recommended lifetime, no replacement (this recommendation conflicted with the maker of the transmission, Aisin) |
–60,000-80,000 first change (12 qts) –20,000-40,000 interval after the first (12 qts) –If over 110,000 miles doing 1st change, do a 2nd change within 500-1k miles (12 qts). Then follow the 20k-40k interval. –Use specific transmission spec fluid. Do NOT use multi-spec/universal trans fluid. Depending on year and VIN, it’s either JWS-3309/T-IV (better Synthetic T-IV option), or JWS-3324/WS for later years. –Reviews on using Synthetic Ravenol T-IV |
⭐Here’s a list of serpentine, decoupler (A/C side), and vacuum pump parts and part numbers. (New)
Serpentine Belt Service (plus water pump, thermostat, & hoses)
I’ve done all the 3.2 maintenance myself and I suggest not to wait until 150k miles to do the serpentine belt service. I suggest to service it closer to 100k miles. This should include the belt, pulleys, tensioner, water pump (kit), water pump coupling, and thermostat (add upper/lower radiator hoses, small oil cooler hose & its o-ring). At ~90k miles, I could already hear pulley bearing wear noise (scratchy). You can start with the first link below (workshop manual, 3.2 serpentine) and work through the following pages for a guide on the process. I would add to do the thermostat at the same time as the water pump. I did not use any special tools. The thermostat assembly is electronic (has a temp sensor) and accessible under the intake manifold. I was able to change it without removing the intake using a long extension and a flex joint (or universal joint). Lastly, on the drive belt itself, use a good brand, such as Volvo or Contitech. I have used Goodyear or another brand in other European cars and they are not the right size.
– Use quality Volvo coolant or equivalent European formula, such as blue G48 coolant spec.
➕ Many people change the large radiator hoses, but miss one small oil cooler hose and o-ring. The plastic end of the small hose can get brittle & break and the o-ring can start to leak. This is the thread for the small hose and o-ring people miss. Part numbers: small hose 30713530, o-ring 31109235. Good idea to change at the same time. Double check a plastic piece didn’t break off in the engine block, this is common.
❗ Keep an eye on the coolant reservoir because between 100k-150k miles there have been multiple reports of the plastic nipples fatiguing & cracking, where the coolant hoses connect to. Some replace this reservoir as well as the cap (it’s a pressure release).
Videos & info for the serpentine & cooling:
Decoupler & seal (new)
This has been seen to last ~120k-150k miles, but needs the serpentine to be apart.
**Best is to combine this job with the serpentine work at 100k miles because this decoupler pulley drives the serpentine system and the seal will leak oil. When removing the serpentine, you will be 90% done with the work involved in accessing the decoupler. You can test if the decoupler pulley will spin one way and not the other.
This decoupler (a.k.a. overrun clutch) and seal are on the A/C side of the engine.
*(TIP) The direction for loosening this decoupler pulley bolt is standard thread direction (righty tighty, lefty loosie), but needs a special tool to hold the decoupler pulley while loosening the torx center bolt. This decoupler helps prevent READ issues by reducing shock since the decoupler allows the serpentine system to free-spin like a 10-speed bike when the engine rpms drop.
❗This decoupler seal is solely the main source of an oil leak in the 3.2 engine (minus the vacuum pump). Change it when you have access doing the serpentine job before it becomes a mess.
⚠This decoupler pulley could be listed under the alternator section in parts lists, but you will know it’s the A/C side decoupler because it has ribs on its pulley to match the serpentine belt.
*(TIP) The decoupler seal does not need a special tool if you purchase a quality aftermarket seal. Don’t pay extra for a Volvo seal tool just for this. Here’s a thread showing how the quality aftermarket seals come with a plastic tool.
➕ up to 2010, 3.2 A/C bracket may need an alignment tool. Upon removal of the A/C bracket for the decoupler access, there are spacers for the mounting bolts and a spacer washer under the center of the bracket. You can get away without an alignment tool if you don’t spin/turn the adjusting spacers, mark their position & the bracket position, and tape the spacers from moving while you do the rest of the service. If you do accidentally move/spin the spacers, then you need to find the tool 999-7262. Here is a thread on it. You can find this tool as aftermarket, or on ebay. I bought one off of Amazon (JM Auto Tools brand).
-Get the: decoupler, cover (might come with the decoupler), seal, and new bolt in case you strip it. Add the special pulley torx bolt tool (CTA 1072).
Oil Selection
I’ve done tons of research and shared my work/experience on other posts. I suggest Mobil 1 FS Euro 0W-40 (A3/B3, A3/B4) for its cold weather flow, high temp protection, and amount of zinc. The zinc can help prevent wear associated with 3.2 oil consumption. Also, use a good oil filter such as Mann, Mahle, or Volvo. I like to keep a 5,000-5,500 mile oil change interval instead of 7,500. Oil is cheap compared to engine work due to oil consumption caused by premature wear. I don’t like conventional oil for this modern engine because conventional oil with use can get too thick on cold temp start-ups and too thin when hot. Too thick of an oil on cold temp start-up might bypass the oil filter because of the high oil pressure as well as take longer to reach the vital engine parts. A bad combination. Lastly, do not overfill the engine as the oil may go through the PCV.
❗ If you look at the threads with the oil analyses linked below, the synthetic 5W-30 oils (typically A1/B1, A5/B5 spec) shear down to a 20 weight by ~3k miles.
Oil consumption, P0420/P0430 code (new)
These two issues can be related. Oil consumption affects both variants of the 3.2 engines. The key factor is to use quality synthetic oil with shorter 5k mile oil change intervals. If your 3.2 has been strictly maintained at the dealership, this can cause the oil consumption issue due to the extended oil change intervals (oil breaks down and can lead to carbon buildup). Look at the used oil analyses listed in the “Oil Selection” section to see why the dealership/Volvo 7,500 oil change interval can cause issues (the 5W-30 oil also shears down, gets too thin).
❗PCV (a.k.a. oil separator/air handler) Don’t underestimate the importance of this part!!
*(TIP) Don’t wait to change this whole box with a good OE or OEM one (avoid cheap). In addition to oil consumption and vacuum issues, an old PCV can lead to, lean, rich, and catalyst inefficiency codes, P0420 & P0430. People have chased issues spending a lot more money on other parts & work when the main culprit was the PCV.
Many many newer engines use an internal diaphragm for the PCV or crankcase ventilation. This part on top of the engine can cause a whine or vacuum sound (it can also be quiet) and may cause an oil consumption or running issue. I also suggest a scheduled replacement around 100k miles. It is not if but when the diaphragm rubber will break (same in many other new engines across different makes). Easy to change. It’s a 10-minut job.
*(TIP) Get the entire PCV unit either Volvo or OE FoMoCo brand or Land Rover. All the same good quality, but the Volvo brand could be cheaper at times. Avoid cheaper aftermarket copies as they can have issues. It may look similar, but do you know how much vacuum their PCVs operate at?
⚠ This part does not need to be whistling to be bad. Before it completely fails, or contributes to oil consumption without noise it’s a good idea to change it. This oil can affect all cylinders and can also travel to the catalytic. A failed PCV can affect both banks of cylinders from running properly.
Alternator
This is a part that could fail, but it is not difficult to change. It is also known because the bolt for the drive gear can come loose on the READ side. ❗ If this decoupler seizes, it could cause the drive gear bolt to loosen, connected to the READ side (click for forum thread), causing a charging issue. Regarding trying to refresh an alternator, sometimes it makes more sense to change an entire alternator rather than trying to refresh it with a new decoupler and voltage regulator parts. The cost of those parts could equal 60%+ of a new alternator, and refreshing an old alternator would still have an old bearing. A new alternator should have a warranty as well (lifetime if from FCP). Here are videos to help guide changing it. If you have to change the alternator or have access, remove the decoupler’s drive gear bolt (READ side) and add blue Loctite to prevent it from backing out. New intake manifold seals should be used and the Victor Reinz ones are affordable.
⚠This decoupler could be listed under the serpentine section in the parts lists and it has a cog gear (has teeth) as its pulley.
Videos for the alternator:
Engine Mounts
Do them around 100k miles. Depending on driver history and driving style, you can go longer or shorter. All XC90 engine variants will need engine mounts. The 3.2 does not have the same type of upper torque mount style as the 2.5 or V8, but has one on the passenger side. If you hear a metallic vibrating noise, it could be your upper torque mount. Hutchinson brand is a great brand alternative to the original Volvo.
- Replace the 1) front, 2) rear, 3) upper passenger side torque, 4) lower passenger side, and 5) the transmission torque mount under the driver’s front side.
- If worn-out engine mounts are left in place, allowing the engine to move and shift, this could lead to premature wear on the driveshaft, axle CVs, and older rusty exhausts.
Spark Plugs
I like to use original Volvo ones, but people (and I) have used Bosch. I think Denso is used for the later S5 engine (2011+). I don’t trust other brands as far as it running smoothly in the engine. Change around 50k miles because the 3.2 likes to rev on downshifts. That extra use in upper rpms can increase spark plug wear.
Ignition Coils
These should last a long time. The 3.2 does not suffer from the same coil pack issues seen in the 2.5t. You can wait until one goes and then replace all 6 so there is a more equal spark between cylinders. Also, change all six because if one goes, the others might not be too far behind. If you want to change them on a scheduled timeframe, then 150k miles is a good mileage based on normal wear on the coils/boots (people do see them last past 200k miles, some have not). If your 3.2 has over 150k miles and you are planning a road trip across the country with kids, do the coils. These can stop your drive and might take days to source parts (depending on your location), worse if it’s a weekend. Delphi coils from FCP should be marked FoMoCo and are OE coils, but double check. Post further down this thread about replacement coils.
Brake Vacuum Pump
The seal for the vacuum pump can leak oil. The remedy is an affordable kit. Not difficult to do and easy to check for the oil leaking. It can go at 60k miles or at 120k miles, not really mileage specific. Fix if leaking.
*(TIP) There is a plastic coupling/connector connecting the brake vacuum hose to the vacuum pump. This important connector can break easily upon removal due to the brittle plastic spring clip lock. Here is the replacement part number (30714933 ) and a thread about it.
Videos:
Fuel Pressure Sensor
This sensor will fail, do it around 100k-120k miles. This part is shared across engines and models for Volvo and is a known failure sensor indicated by a trouble code. Buy Bosch. There is less room to remove the holding screw than in a 2.5t. I used the same bit ratchet used for the water pump coupling and a flathead screwdriver wrapped in a towel to give very little side force to keep the ratchet straight (between the ratchet and valve cover hump). Another option is to purchase an “L” shaped torx set. It is vital to use the correct size torx so you don’t strip the screw. Should be a tight fit and you can test the fit on a new screw (p/n 986201).
Fuel system cleaner, Fuel injection cleaning (new)
With the 3.2 engines getting older and you have already changed the fuel filter at 100k miles, the next thing to do for maintenance is a good modern fuel system cleaner. This will help with rust cleaning, the negative effects of ethanol in gas, and build-up in fuel injectors. You can do every other oil change. Some people do it before each of their oil changes so any contaminants that go into the oil are removed.
R.E.A.D
You do not want this problem, but if you hear metallic bearing noise around the serpentine area, then you may have a READ issue, but I haven’t really heard of people having an issue recently. Personally, I think good oil and good oil change intervals can help with this area. Most of the 3.2s with these issues have already expired from the market. Here is info on what it takes to fix it.
Technical Bulletin (TJ)
This is if there is an oil consumption issue. Many still do not have it, including mine. It is helpful in what to look for, such as with reading the spark plugs.
http://australiancar.reviews/_pdfs/Volvo_Technical-Journal-24643_I6-oil-consumption_201204.pdf