Extreme blow-by - No sludge in Oil Pan - 2007 XC70

[cmayo1]

Here's some backstory:

I bought a 2007 XC70 with 227k (yikes) miles on it for $800. The car struggles to find it's pep, but doesn't stall and starts everytime (knock on wood). It also had some check engine codes that we cleared before driving it home. I've attached the codes in a picture.
The car needed to be driven ~40 miles home, and it made it with no check engine lights back on (later I drove it another 5 and still nothing).

I started a compression test and found oil in the spark plug sockets. Like, a lot of oil, but more so in certain cylinders. 2 and 3 had the most, 1 and 4 had fresh oil, and 5 had old, sludgy oil. The top had oil underneath the cover, but closest to (what i assume is) a tube that moves oil somehow, because a majority of it was right next to that tube. I'm 80% sure that tube works with the PCV, but I'd like to be corrected. Also, taking off the tube did not reveal any sludgy oil.

We tightened it up, cleaned the oil out, let it drain and ran the compression test. All the cylinders were about even at 145-150psi. We started it up and it came back on fine. Next day, ran the compression without oil in the cylinders and got around 180psi for all. (im worried that me clunking the cheap-o compression gauge i bought caused it to fudge numbers, but all numbers were close to one another)

Now, I know the check engine code says that the CAT is going, but once we started it after the compression test, plumes of smoke came out of the exhaust from the oil in the tubes. There is also an exhaust leak between the resonator and the catalytic converter (the leak is after the CAT, not before) and plumes came out of there as well.

I took it around the block, maybe 5 miles, to get it warm to see if there was blowby coming out of the dipstick, which there was. At that point, it solidified to me that this was a PCV problem.

Now, from my understanding, PCV issues can also contribute to sludge in the oil pan where it drains to the bottom of the pan. My first thought was to drop the oil pan rather than do the entire PCV job in case I needed to move the car, since it seemed more reasonable to do. Once I got the pan off, there was no sludge.

Zero.

Can someone please ease my mind a little and tell me what might be causing this much blowby? Would a bad CAT cause blowby in the dipstick hole? I'm talking a lot of blowby, just white clouds coming out the oil cap and dipstick. Is this a PCV problem that just hasn't got to the oil pan?

Thanks in advance!

tl;dr - oil in all spark plug sockets *potentially* caused by a PCV tube in between cylinders 2 and 3 that isn't clogged. majority of oil in cylinders 2 and 3. good amount of blowby out of dipstick, but no sludge in oil pan. Exhaust and CAT easily pushes out fumes, but check engine light says bad CAT? or PCV issue even without sludge in the oil pan?

[erikv11]

I don't see any bug read flags in the codes. Exhaust leaks and vacuum line leaks could account for most of them, but most importantly is probably see which ones come back.

That hose you talk about to the top of the cam cover is indeed part of the PCV system. All the oil on top could have easily come from that. Maybe just that hose was leaky where it fastens, maybe the PCV was clogged causing it to leak, maybe both.

The blowby could easily be caused by clogged PCV system, without sludging up the pan. A similar test (the "glove test") commonly done for clogged PCV is to remove the oil cap and put a latex glove over the hole, and see if the glove inflates (PCV blocked) or sucks in (PCV working) with engine revs.

If you still have the pan off, super useful would be to check the square drain hole/tube from the oil trap (part of the PCV) into the pan.

Sounds like it needs PCV work then go from there. I didn't think carefully about the CAT part of your question, maybe someone else will

[cmayo1]

Thanks, Erik. The glove tests does exactly what you expect: blows it up like a balloon. There was no sludge in the drain hole whatsoever. I have the kit for the PCV, so I'll probably just end up tackling that.

[cn90]

The PCV hose PN is 8692217.
About $45 at Volvo dealer or FCPEuro.
Do not use Rein or Vaico, it will break in 1-2 yrs.

If you are so short of cash, then use a standard heater hose with I.D. = 5/8" and clamps.
Just make sure the bend of the generic hose is gradual and not pinched.
Yes, you can do all this without removing the I.M.
I posted the tricks in this forum. Basically use an appropriate socket to enlarge the inside of the hose a bit, add some oil and it will slide on top of the oil trap.

Leave the rectangular cosmetic cover out for now so you can monitor the oil leak.
The plastic cover that is over timing belt: no need to remove it.

PS: at this age and mileage, yes, do a PCV overhaul when you have time/money.

[cmayo1]

Thanks, CN. If you have the title or link to the post, I'll bookmark it for later. I haven't run it enough to see if the leak continues, but I have the whole overhaul kit from FCPEuro which includes that hose, so it'll be changed anyway.

[cn90]

My trick was just for that one hose.

If you already have the PCV kit, then you need to remove the I.M.

If you happen to replace the tsat, then access to that notorious bolt is easy.

[cn90]

Btw, all of my P2 Volvos: I remove and store the cosmetic cover on the garage shelf. This way I can easily inspect this area for oil leak. It also makes it easy to check/replace ignition coils, plugs.

[erikv11]

That's a good idea to consider replacing the thermostat at this time. More $ out of the pocket but much, much easier during a full PCV service.

I read your post again but I don't really know about how e.g. a clogged cat could be relevant here.

[jonesg]

these simplify t'stat removal.

https://www.amazon.com/Neiko-10080A-8-I ... r=8-5&th=1

very low profile 10mm univ socket for the problem bolt, uses 1/4" ext.

https://www.amazon.com/dp/B07R7JKG74?re ... title&th=1

[Krons]

Definitely want to replace the PCV components before the pressure pushes out cam seals or main seals. Keep the dipstick out a bit if you have to drive it to relieve the pressure, maybe cut a slot in the oil cap rubber gasket too.

FCPEuro sells the whole kit. Not very technical but a lengthy process, a number of YouTube videos on it. I got cold feet and let my good Volvo Indy mechanic do it lol.

If you drop the pan, at your mileage you will want to replace the pickup tube orings as they can get brittle and suck air causing low oil pressure.

When was the timing belt last done? Hate to ask…if not recent may want to do cam seals, water pump, tensioner, idler and hoses to make it bulletproof. It’ll be good for 300-400k if cared for.