Engine oil blow-by problem

[dom14]

Hey guys,
This has been going on for a while. I have managed to(thought I did) fix the problem for a while
with a brand new PCV valve, but after few weeks, it's back again.
The blow-by is as on the pictures. Mostly from the rear passenger side of the rocker cover gasket.
Gasket is brand new. The bolts are tight enough. I recently disconnected the PCV hose from the PCV valve and
plugged the PCV valve. So, basically the hose and blow-by is venting into the engine bay atm.
I did it with the idea of addressing the "excess blow-by" issue.
Regardless of that, the blow-by continues from the ear passenger side of the rocker cover gasket.
The blow-by from anywhere else doesn't bother me, 'cos there isn't a lot of blow-by to create a mess in other spots.

It appears to happen after engine fully warmed up(or may be not), and on higher revs(if my observation is correct).

I think the engine heat and the high revs contribute to it more.

I didn't do any compression tests or leakdown tests this year, but last year they came out ok.

So, what's going on with this troll?

I would like to fix it once for all, 'cos the oil mess is not good after few weeks, from the rear passenger side of the rocker cover gasket, as in the pictures. Dripping oil creates a mess on the block, clutch housing and perhaps it gets inside the clutch housing as well.

Any tips, ideas, advice will be appreciated.

P.S. It's an RB30, carby model. No engine modifications. I'm running 10/30 oil atm, even though it's the summer.
Usually I run 20/50 during the summer.

[nissannewby]

In the second pic it looks as though the gasket has blown out. Is this the case or am I looking at it wrong? Is the rocker cover sealing face on the head flat?

[mudnut]

Have you put a straight edge on the rocker cover, as over-torquing of the screws will warp the alloy cover.

[dom14]

In the second pic it looks as though the gasket has blown out. Is this the case or am I looking at it wrong? Is the rocker cover sealing face on the head flat?

THe gasket is good. The gasket goes into a groove on the edges of the rocker cover, and there's a few millimeters or protuberance.
So, I think even if there's slight warping of the rocker cover edges, it should seal ok. But, I can assure the rocker cover edges are flat and there's no warping, 'cos I tested it on flat glass surface, as well as with a machinists ruler(last time). Sealing edge of the cylinder head is also flat without any warpage or bumps.
I'm pretty sure it's excess blow-by. But, I am at lost why it oozes out of the rear end of the rocker cover gasket, instead of blowing out of the PCV vent hose.

Even turboed engine's blow-by that is managed with catch cans, etc and they don't blow by the edge of the gasket.

Only thing I haven't done so far is to super tighten the rocker cover bolts to see if that fixes the problem.

[dom14]

Have you put a straight edge on the rocker cover, as over-torquing of the screws will warp the alloy cover.

Yeah, I did it last time before I replaced the gasket. It came out as fine. I couldn't see any warpage on the rocker cover edge or the cylinder head edge.

May be, I'm tightening it wrong? Not properly balanced?!! Or not tight enough??!!

[dom14]

How about installing an extra breather line from the rear end of the rocker cover near where it's leaking??!!
And perhaps plumb that into the air cleaner?

[nissannewby]

Are those fittings and hose for your breather and pcv after market?

Did you actually torque the bolts with a torque wrench?

[Throbbinhood]

Hey Dom!

I had that exact leak in mine. I replaced it with a new gasket, and a few weeks later had the same leak.

Re-tightened all the bolts, this time with the tiniest bit of thread lock on them, and it's been fine ever since.

Probably doesn't help you much - but if you haven't torque'd them with a torque wrench, maybe they need to be nipped up a bit more?

[dom14]

Hey Dom!

I had that exact leak in mine. I replaced it with a new gasket, and a few weeks later had the same leak.

Re-tightened all the bolts, this time with the tiniest bit of thread lock on them, and it's been fine ever since.

Probably doesn't help you much - but if you haven't torque'd them with a torque wrench, maybe they need to be nipped up a bit more?

It did help mate. I think, part of the problem might be that those bolts at the back coming loose from the vibration.

I'll give it a go.

Thanx

[dom14]

Are those fittings and hose for your breather and pcv after market?

Did you actually torque the bolts with a torque wrench?

Fittings are stock ones I think, 'cos I've never replaced them, as well as the hoses.

I didn't use torque wrench for the bolts. I thought, having done heaps of them, my hand feeling might be as good?

May be, to get the right balance for each bolt, I better use a torque wrench?!

I'm not quite sure how I adapt my 1/2" torque wrench for that job. I might have to get creative and use an adapter.

[Throbbinhood]

Fittings are stock ones I think, 'cos I've never replaced them, as well as the hoses.

I didn't use torque wrench for the bolts. I thought, having done heaps of them, my hand feeling might be as good?

May be, to get the right balance for each bolt, I better use a torque wrench?!

I'm not quite sure how I adapt my 1/2" torque wrench for that job. I might have to get creative and use an adapter.

FWIW, I didn't use a torque wrench. Just did it by hand, reasonably tight without damaging the rubber washers. As I said, bit of thread lock or similar - as my rear ones had basically come all the way undone.