2003 XC70 Where's my oil going?

[mikealder]

Carry out a compression test both dry then wet on all cylinders as it could be worn bores/ rings, if this is the case reconsider what you are doing as a replacement engine is often cheaper than a rebuild.

As for the PCV, I replaced everything except the expensive hose which is the one for PCV blow-by gas to return to the inlet for re-combustion, it is also heated by engine coolant, I simply removed the PCV blow-by pipe leaving the coolant part in place then replaced the PCV blow-by pipe with some 5/8" hose, took about three hours in total.
When you get the PCV tank off the engine connect a length of 5/8" diameter hose to the lower port in the engine block where the PCV tank was connected and try to blow through it, if it is blocked you will need to clear this port out which could involve dropping the sump and the drain port goes down through block all the way to the bottom of the sump before turning upwards, cleaning this out is neigh on impossible without sump removal - Mike

[carboncow]

As for the PCV, I replaced everything except the expensive hose which is the one for PCV blow-by gas to return to the inlet for re-combustion, it is also heated by engine coolant, I simply removed the PCV blow-by pipe leaving the coolant part in place then replaced the PCV blow-by pipe with some 5/8" hose, took about three hours in total.

Mike, Great info...

My one buddy took clear flexible plastic hose and pushed it through that lower port into the sump. He says you'll see the 'crud' collect inside the hose, cut that off and keep trying. It isn't perfect but he says you'll he surely opened that port up. He said if you could figure out a way to put a vacuum not it (think shop vac with ductape technology) it would be really cool. Oil change and flush and again in 3K miles was his plan...says he's daughters 99 has been running 3 years since the PVC replacement and clean, has negative crank case pressure and he felt that port was pretty nasty to book. I like his idea.

I may very well do a compression test to see where I'm at but as stated before I have great power and nothing nasty coming out the back...but at least I can see if one cylinder is out of whack. I'd probably not worry about an engine swap/rebuild on a 2003. The price I got this car for 4 years ago $4200 it's pretty much disposable for a dependable daily driver...I could sell it for $3500 all day long and still disclose any concerns as I do.

Are you stating the whole job took 3 hours for you or fabricating the new unique pipe? I'm going to keep re-reading your solution and see if I can fabricate similar. Was that pipe pretty crudded up?

[PierreC]

This post prompted the following ...

I had a similar mysterious oil loss on my 2002 XC70 (135.000 miles at the time) but PCV pressure at idle was negative - it "sucked" the glove. I hadn't tested the pressure at higher engine speeds, but blew the camshaft seals ... so I assumed the PCV was clogged. So after a very expensive camshaft seals repair at the dealer, I ordered the full IPD PCV kit and had it fitted by my local indie (who happens to be the workshop foreman for another Volvo dealership). It was quite interesting that the PCV was not completely clogged - there was obviously some clogging, but none of the circuits or pipes or elbows were totally clogged - so I am not convinced that the only cause of the blown camshaft seals was the PCV system.

And to add insult to injury, the oil consumption is still very high. I have used used Total Quartz 5W-40 synthetic oil since new, so the oil consumption is unlikely caused by wear and tear due to inferior oil. This continuing oil loss has got me stumped.

Pierre

[mikealder]

My one buddy took clear flexible plastic hose and pushed it through that lower port into the sump. He says you'll see the 'crud' collect inside the hose, cut that off and keep trying.

That was the same method I tried but I couldn't clear the bit at the end of the oil drain, have a read through https://www.matthewsvolvosite.com/forums ... =1&t=55413 to see the pictures from when I did the job including the internals of the sump for an idea as to why it is difficult to clear the last bit of the PCV oil drain.

Three hours was the time taken to strip and re-build it, it excludes the hours spent trying to clear the oil drain and subsequent oil sump removal - Mike

[carboncow]

My one buddy took clear flexible plastic hose and pushed it through that lower port into the sump. He says you'll see the 'crud' collect inside the hose, cut that off and keep trying.

That was the same method I tried but I couldn't clear the bit at the end of the oil drain, have a read through https://www.matthewsvolvosite.com/forums ... =1&t=55413 to see the pictures from when I did the job including the internals of the sump for an idea as to why it is difficult to clear the last bit of the PCV oil drain.

Three hours was the time taken to strip and re-build it, it excludes the hours spent trying to clear the oil drain and subsequent oil sump removal - Mike

Mike,

Checked out your post on cleaning the PVC. Any good writes up on dropping sump...I have no idea what that entails but if it has todo with pulling the engine I'm going to freak! Thanks.

[carboncow]

I hadn't tested the pressure at higher engine speeds, but blew the camshaft seals ... so I assumed the PCV was clogged.

Pierre

So do the glove test at 2000 rpm and tell us what you see. The system is two part...idle and at boost/rpms. one or both can fail.

[PierreC]

So do the glove test at 2000 rpm and tell us what you see. The system is two part...idle and at boost/rpms. one or both can fail.

As I stated, before I could do the glove test at higher engine speed (2000+ rpm) the camshaft seals blew and (after fixing the camshaft seals) I then replaced the complete PCV system with the IPD kit ...

Is there a chance that there is still a problem in the PCV system (boost part) even after replacing the complete PCV?

[carboncow]

So do the glove test at 2000 rpm and tell us what you see. The system is two part...idle and at boost/rpms. one or both can fail.

As I stated, before I could do the glove test at higher engine speed (2000+ rpm) the camshaft seals blew and (after fixing the camshaft seals) I then replaced the complete PCV system with the IPD kit ...

Is there a chance that there is still a problem in the PCV system (boost part) even after replacing the complete PCV?

I don't know enough of the system to answer that...but I do know there are the two variables to the PVC system. You would hope that both are covered by the kit but as we have discussed with others there can be blockages in the block...and knowing that ahead of time can allow one to make sure they are clear (I'll be doing the procedure this evening). In theory you could still have a blockage.

Maybe another can talk about the passage to the sump with the 180...if blocked does this cause high rpm positive pressure?