Hi All,

Here is a puzzler. We bought a 2016 XC70 a year ago from a large northeast pa dealership. I did my best to ascertain one issue, does the car consume oil. After a bunch of thousand yard stares, we decided, based on the condition of the car and history, I didn’t.

we took it on a long road trip six months later and, while driving, experienced a bit of engine misfire for a moment. We dropped into a dealer in AL and the plugs were changed and oil was added. We had the oil changed just prior to the trip by the selling dealer and I suspected they used the wrong oil. We drove another 3000 miles on that trip with no oil consumption.

a couple months later after returning from the trip, we experienced the same misfire and noticed the oil level had dropped. The tech explained that the engine was burning oil by showing me the plugs which were white (not black) and suggested this was an indication of oil consumption. They ran an engine wash material through the engine and changed the oil. (They said this was the Volvo recommendation for oil consumption to loosen stuck rings). After about 2500 miles we started consuming oil again at a rate of 1 qt per thousand miles. We started the process of tracking oil consumption at the dealer, had only them put oil in the engine. I was moving to perform the piston swap on the engine and after about four services we had started the process.

I lost faith in the dealership after the service manager quit so I went to a second dealer near my work and asked them about the oil issue and they gave me a lengthy explanation about what the issue is with the engines and why they consume oil. I brought the car there to restart the process of oil consumption analysis. They changed the oil and at 1000 miles I brought the car in for an oil level check. NO CONSUMPTION.
We’ve driven the car about 1800 miles and still no consumption. The level is right at the top.

I'm scratching my head on this one. We are using Castro’s Edge a professional 10-30 as recommended by Volvo. We didn’t pull any plugs but, I’m starting to wonder what else could be causing the engine to consume oil. My 99 S70 had a bad breather box assembly which caused it to smoke and burn oil but This car doesn’t smoke (I understand that the cat will hide smoking).

thoughts?it’s got 90,000 miles on it now and we bought it at 71,000 miles.

 

there's a pretty short list of where the oil can go. Thinking about it, here's my list (not in a priority order) 1) PCV oil separator - it has a vacuum actuated diaphram which when it tears will allow oil to get into the intake air 2) ring issues - as noted they can get "stuck" in the piston's grooves, be worn and out of tolerance or there can be damage to the cylinder walls. Testing of the oil along with other tests can help determine if this is in play. Note there were service bulletins for the 2012 or so model year where this was a known point of failure that you can read up on. 3) valve seals - oil can leak into the cumbustion chamber (particularly over night) not a common issue on young cars but the symptoms are a puff of smoke on a cold start and a puff of smoke when engine braking (ie put car in low, take up close to the red line and step off the throttle). 4) head gasket issues/cracked head/cracked block. Tests here are to see if there's any mixing of oil and coolant etc 5) turbo seals - this canproduce smoke, mess with O2 sensors/cats but may leave plugs clean. 6) leaks. on older cars like my Gen 1 S40, the VVT can leak as can cam seals, particularly if the PCV gets clogged.

I think you are are the right path 1) use the correct weight oil and OEM oil filter 2) monitor the consumption over time and driving conditions (ie city/highway) 3) do a close inspection of the intake and other areas for leaks or signs of oil getting into the intake or coolant. 4) work with the service manager at your dealer. Note not all techs are equals when it comes to the hard to diagnose. Talk to the service advisor first or find a top end euro car indy who has lots of experience and see what they recommend.