Engine: B5244: Occasional heavy oil leak

[VroomVroomClonk]

I seem to have a major oil leak from somewhere behind the cambelt covers, but only sometimes. I recently checked the oil level and then went on a journey of several hundred miles and didn't seem to lose a drop. Then the car stood for a few days before I took it out again for about 100 miles and got oil sprayed under the car so badly that it was even all over the osr wheel arch and sprayed all up the tailgate.
This has been going on for over a year, but it will be probably be fine again now for several weeks, until one day it will all come spraying out again.
So, does anyone know please if it is possible for a PCV to fail, but just sometimes? I've tested it with a glove over the filler hole and it sucks the glove empty. But could a PCV fail in such a way that on some days I'm getting a lot of positive crankcase pressure that is blowing oil out past the oil seals on the camshafts or crankshaft, but on other days work fine again?

[oragex]

I haven't heard of such behavior. If the glove sucks in and there's no consistent vapors through the dipstick, the PCV should be good. Was it already replaced? How many miles on it?

If the car was bought used, it's not impossible that a previous owner had to replace these seals and installed them at the wrong position or even put other than OEM seals

I'd also inspect the main rear main seal while there

[ASt85]

Originally Posted by VroomVroomClonk

Have you checked to see if the oil is leaking out?
I still haven't worked out why mine has the occasional but very heavy oil leak that I raised here https://www.volvoforums.org.uk/showthread.php?t=281231

I've read your post at https://www.volvoforums.org.uk/showt...=282990&page=2

From your tagline I assume yours is a T5 - which has a turbo - I'm sure I've read something about the intercoolers failing or cracking in these models and then intermittently leaking large quantities of oil which gets sprayed back over the underside of the car.

However, it could be that the oil seals on the turbo have failed but I'd have thought you would have seen smoke from the exhaust

[VroomVroomClonk]

The car has just been in for its MoT, and whilst it was up on the ramp the MoT tester kindly let me have a look underneath, and so I can definitely confirm that the oil is coming from within the cambelt housing.
The last time I took the cambelt covers off, it was such an oily mess under there that I couldn't see where it was coming from, so I cleaned it up and then waited and waited for some oil to come out, but nothing. Then, many weeks later it all came running out under the car again so I took the covers off and everything was so covered again that I couldn't see where it had come from.
I really don't want to continue like this, so I think the best thing for me to do is to replace every possible oil leak-point within the cambelt cover. The things I intend to change are both camshaft seals, the crankshaft seal, and any oil pump gaskets and o-rings. Have I missed anything? Can anyone think of anywhere else oil could possibly be coming from in that area of the engine please, or anything else I should be doing as well?

Many thanks.

[Brendan W]

If I had to choose it would be one seal only and it would be the crank. If the cams are dry I would be slow to 'fix' them.

[oragex]

Just make sure to use genuine seals, and install them properly - there are DIY on line showing how to install the seals (some pushed them too far deep and had to do the job all over again).

The PCV must be replaced after 80K miles or 10 years in my opinion, along with all associated hoses

[VroomVroomClonk]

OK, I think I have finally found the cause of this leak, but I'm unsure how to fix it.
Firstly, I have replaced the front crankshaft oil seal, along with the oil-pump O-ring and gasket, which made no difference.
Then I checked the PCV, which was completely clear, and I mean absolutely clear, not even any blockage in the 2mm bore pipe to the banjo union on the inlet manifold. However the small 2mm ish bore plastic pipe was brittle and cracked when I removed it so I replaced that, I also replaced the brittle cam cover breather hose, and the short (75mm ish) crankcase breather hose. But still no difference, ... which is not surprising as there was nothing wrong with it in the first place.
So, I think the problem actually is the front exhaust camshaft oil seal doesn't properly reach the sealing surface on the VVT hub. There is lots of information on the internet warning about not inserting this seal too deeply and I'm aware of that. My old seal was set about 0.8mm back from the front face of the casting, i.e, not even fully to the bottom of the chamfered edge and yet it only just touches the sealing surface on the vvt / sprocket unit. See the polished shiny ring at the very edge on the attached photo.
So, I fitted a new seal, exactly flush with the front edge of the casting, and it seemed to seal fine for a few minutes but then got pushed out of the engine and the oil came pouring out. So what do I do? if I set the seal in any more deeply it doesn't reach the sealing surface. If I make it reach the sealing surface it doesn't have enough grip in the block to stay in!
With the cambelt removed, the VVT hub has no detectable radial wobble, but it does have a few mm of axial movement and a slight but detectable movement when rocked up and down or left to right (in the way that you would hold and wobble a roadwheel to check a wheel bearing). Does this mean that I need a new VVT hub? Is that why the seal doesn't work? If so, is a VVT hub a main-dealer only part in the UK? They seem to be available on eBay in the USA but nothing over here! Does anybody know the approximate price for the part from a main dealer please?
Or, am I completely missing something? From what I can see, this seems like Volvo have got this design completely wrong, and have simply put the seal in the wrong place to actually run properly on the correct part of the sprocket hub. Or is there something wrong just with my particular engine, and things are out of position somehow?

[oragex]

Empty pcv doesn't necesarily mean good pcv. It needs replaced anyway around 100K miles, along with the hoses and thd ptc nipple.
The czm seals are not flush with the surface, but flush with the bottom of the circular groove like here at 3:00 https://m.youtube.com/watch?v=ziXvdvR251w

[VroomVroomClonk]

Originally Posted by oragex

The czm seals are not flush with the surface, but flush with the bottom of the circular groove like here at 3:00 https://m.youtube.com/watch?v=ziXvdvR251w

But if I set the seal to the bottom of the circular groove like that, then it will touch the sealing face of the hub even less than the old one did?
When the old seal was set only half way between the front face and the bottom of the groove, it produced the polished silver wear ring that you can see right on the very extreme end of the sealing face in my last photo. And that leaked, so any further towards the bottom of the groove and it will leak even more.