1998 V70XC - Oil Leak Puzzle

[VolvoOwl98]

There was a thread where someone rammed stiff Pcv tube into the block hole and packed it full of carbon gunk, then cut that piece of tube off , rinse, repeat. This cleared the draft hole without dropping the pan

That’s a neat trick, I’d be interested in reading through that thread. I still have to drop the pan eventually, I’ve got a kit with new seals and it looks like the pan hasn’t ever been touched (safe for the nice dent on the underside)

[VolvoOwl98]

There was a thread where someone rammed stiff Pcv tube into the block hole and packed it full of carbon gunk, then cut that piece of tube off , rinse, repeat. This cleared the draft hole without dropping the pan.

Once you get it partly open, bottle cleaning wire brush and routing to get it clean.

Maybe Mike alder from Australia wrote that up? It was someone famous

Looked for a while to find it, wasn't able to find the discussion though

I did find this thought, viewtopic.php?t=53246, as well as the thread I earlier mentioned in passing for an improvement to the PCV system (viewtopic.php?f=1&t=53448#google_vignette which I'm thinking of doing for good measure also

I did some inspecting around, and there's still definitely a leak, but with the culprits in mind (and thanks to the blessing bestowed by some visiting family) there's numerous parts on the way (front and rear camshaft seals, front crankshaft seal, oil pump gasket/o-ring kit, and oil cooler line kit), with the goal being to install them after resolving the PCV issue

Two good bits of good news, one being that she's seeing fewer miles per week so that should slow issues becoming worse, and that upon inspection of the turbo oil return line it's as dry as a bone (thank goodness! I don't have to deal with that pain in the hands again)

I am certainly curious to see why crankcase ventilation tube (p/n: 9471644) that runs from the oil trap to the PTC valve has oil leaking from it, especially since the whole system was replaced when I bought Saskia. I am going to try abscate's advice of running a double gasket for the cap, as well as checking the fitment and clamp snugness of the PCV hose at the top of the head

(To clarify, I’m not going for a full timing belt and water pump servicing since that was done only 7k miles ago on 6/6/25 at a Volvo indie shop with FCP Euro KIT-517997 ( https://www.fcpeuro.com/products/volvo ... tbkit217wp) by the previous owner. Also the belt still looks to be in good shape)

[VolvoOwl98]

Saskia's continued to be giving herself an oil change as time goes on, so I'm in the preparation stage to do the following:
- Front and rear camshaft seals,
- Front crankshaft seal,
- Oil pump seal kit,
- Dropping oil pan (replacing seals and cleaning out PCV passageway thingy)
- Re-tapping the drain plug for an M20x1.5 drain plug to replace the stretched threads (OEM M18x1.5)
- New M20x1.5 drain plug (304 stainless steel, CNC machined, copper crush washer, 5000 gauss neodymium magnet (link: https://hpsperformanceproducts.com/prod ... 2641806526)

For a 1998 V70XC, the following bolts are needed if you want to replace the ones securing the oil pan to the bottom of the engine block:
M7x40 - need 3 - p/n: 985322
M7x20 - need 22 - p/n: 985133
M7x100 - need 4 - p/n: 985324

(for the oil thermostat housing (p/n: 3528199) that, as I understand, diverts oil into an oil cooler built into the radiator, two six point socket screws (p/n: 986226) have to be removed (T40 torx), which has some discussion here: viewtopic.php?t=36007&start=30. It would probably also be a good idea to replace the seal (p/n: 1366791)

I already replaced the torque mount not too long ago, so that should be good. Will be buying new bolts for the exhaust camshaft position sensor, the old ones are stiff and seem ready to strip at a moment's notice... (p/n: 986226)

(Will also install new coolant expansion tank, cap, and silicon hosing for it (do88) since they have to be taken out anyway, and the expansion tank is developing internal hairline fractures

[jmartin919]

When I did my oil pan it called for a very thin coating of anaerobic sealant.

[VolvoOwl98]

When I did my oil pan it called for a very thin coating of anaerobic sealant.

Yep, p/n: 259760

[jmartin919]

I used Permatex Anaerobic Flange Sealant