If it has not been attended too, I would suspect the PCV system requires disassembly and cleaning. If this is the problem, and it is not attended too, it will eventually result in leakage.
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I would also recommend replacing the thermostat at the same time.

 

Actually I had the PVC system replaced last year using the kit from iPD iirc.

 

....Has the timing belt service been completed?

 

^^This. On my previous S40, I did not track this down until it was too late. It blew the front cam seals and was pretty expensive to repair. With the car running, listen for a whistle and see if the sound changes while the dip stick is removed. that sound is pressure built up in the crankcase and causes blow by with the oil resulting in oil loss. this will also lead to premature deterioration of the catalytic converter.

 

It would smoke like mad when cold with a blown turbo seal, especially on the exhaust side. Loss of power could be not spooling too.
Hard to say w/o checking the boost.

 

I don't have any smoke when cold starting. Only real loss of power I have noticed is slight loss of power on long hills, where it now downshifts when it previously did not. I'll add checking the boost to list of things to consider.

Any additional help or experience appreciated.

 

I'm still suspicious of the PCV system. Have you tried the rubber-glove/balloon test on the dip-stick tube? Do a search if you are not familiar with this.

 

Thanks, will check into this.

I believe the timing belt was changed at the same time, I'll verify, but I'm not understanding what affect the timing belt could have.

 

... and I don't think you answered about the timing belt system service?? ... this and the PCV service go well together. "Two birds ...."

 

Its just at your mileage ... the belt and associated is due. I would not want you to overlook it ...or you will have far worse issues.

The timing belt will not cause you any of the symptoms you describe ... it just that the belt job and the PCV job can be done together as they share "workspace"... some little savings in disassembly/assembly time if done together.

 

Understood. My tech is a good friend. Last year I took the vehicle to him and asked him to check everything, change anything due, change all fluids, with the intent to keep the vehicle for several more years with this as primary transportation for my wife and family.

Both he and I are big on combining labor items as you suggest, wherever possible, on items that might soon be due ("while you're in there, just go ahead and...") in order to minimize long-term overall costs.

My bottom line for some decisions that are marginal is to ask him "What would you do if it was your car and family?" Certainly maybe not a question you would ask most shops, but one given this man's character I don't hesitate to ask.

Thanks for your suggestions to reduce cost, and your experience; it'll help us zero in on the cause quicker. Any other suggestions welcome.

 

Is there a concise procedure somewhere for checking turbo, pressure, TCV etc.?

 

I have an 06 XC90 2.5t with 132K miles and I've had the same problem for about the last 60K miles or so - consumes about 1 qt per 1000 miles. I've had the PCV service done, no change. My theory is that the turbo is burning the oil if you shut the car before letting it cool down. If I wait the 2 mins or so (at the cost of increase fuel consumption), it seems to make a difference in the oil consumption. I've been using High Mileage oil and recently put 10W40, thinking that the heavier weight may help??? And yes, our MPG has similarly dropped significantly and we get about 14-15 around town. This is even with fairly new LRR Contis on. Need to make sure the tires are properly inflated always. Not sure what else to do but accept it, which is why I also buy 2 jugs of oil when I do the oil change.

fyi- the timing belt is a 120K mile item on this engine along with the fuel filter.

 

06 xc90 2.5t I have 115k on it now, bought new, and have changed the oil every 3k miles. Have averaged around 1 qt consumed per 3k miles. This is slightly higher than normal,considering it is a turbo, but I have it at the Volvo dealership now. They think it might be the turbo leaking but not sure. PCV was cleaned not long ago and is still good. I will report back when we find the issue. Care is still riding great, just recently noticed the slight oil consumption or leak and want to be proactive. I'll keep us informed