Leaky rocker covers

[KWAWD]

Bugger, a couple of the rear low rocker cover bolts are looking wet definitely leaking again. Just noticed them tonight cos i happened to stick my head around there.
Oil level is fine and no drips on the floor, they're just "wet".

So disappointing. Why would this happen, they were properly installed and torqued to 3.5nm?
Are the gaskets stuffed when this happens, even though they're only a few months old?
Or can i just re-tighten them?

Also, i notice a thin wet oil patch on the oil filler cap, coming from around the centre screw. I've wiped it dry a couple of times but it recurs after a few days. Is the cap stuffed?

[MadMax]

Sounds like you are getting a build up of pressure in the crankcase.
Have a look at the PCV valve and hose as well as the hose from the rear rocker cover to the intake tubing.

PCV valve can be pulled out while the car is idling and it should have a definite suck on it when you put your finger on the hole.

With engine off, I would try blowing into the PCV valve while it's off the rocker cover but still connected to the hose and intake manifold, to see if the hose is clear. Same for the spigot on the rubber intake tubing, pull the hose off and attach a piece of fuel hose to the spigot and blow, as well as blowing into the hose you've just disconnected. All 3 "blow" tests should work, ie you can easily blow air through.

If no problems there, see if the oil cap centre screw is tight, and nip up those rearmost rocker cover bolts. They will feel quite loose, but only tighten a bit, say 1/4 of a turn each.

[KWAWD]

Thanks Max, will do. But if this is the case does it mean that the blow by has forced past the gasket where the bolts are looking wet and potentially damaged it?
Do i need to replace rhe gasket again? (Even tho its only 6 months old). If it could be damaged then i'd rather replace it than worry about it, but if theres no chance of damage then i'll be happy just tightening the bolts.

[MadMax]

Not likely to have damaged the gasket. But run your finger along the line joining the rocker cover to the head and see if any is seeping down, on both front and back. Rear one can be a b#tch, as the oil may not get onto the hot exhaust, but end up on the flexible joint of the exhaust system. Then you get the smell of barbecued oil when the engine and exhaust warm up.

[KWAWD]

Thanks again Max. i cant get to one of the rear bolts due to the plenum being in the way, and i think they all should be torqued evenly rather than leaving it, so I'm going to take it back to the place who originally did the gaskets, to do an assessment of what the problem may be and go from there. I just dont have a workspace or tools to do it properly myself.
As for the PVC, i'll do these checks tomorrow and let you know if i find something.

[KWAWD]

PVC seems fine, has plenty of suction when i put the finger over it. Its slightly oily inside, but i guess that would be normal.
I assume the cap must be leaking past its seal.

Interestingly, the bolts look wet and oil can be easily collected with a rag after a run, but once its cooled down its hard to see the residue, its dry with just a thin film of yellow colour. The Penrite 5W is pretty clean and thin.

[KWAWD]

The guys who did the job back in jan have replace the rear gasket again today. I think they did a good job.
Front seems to be ok with no obvious leaks. Also replaced the cap, no signs of blockage of PVC or breather hose.
Interestingly the car seems to have a battery problem now, so i've started another thread.

[xboxie]

Were you looking for it though? These little things sneak up on you, not smart to assume it started 60 seconds before you looked.
Oil viscosity has little effect, as long as your PCV system is in good condition and pulling a bit of a vacuum in the crank case. If the crankcase is running positive air pressure because the valve or hoses are blocked, leaks will appear at the weakest spots - cam covers, oil filler cap, cam/crank seals.

Crap im leaking from the oil cap.

[Spetz]

Is it ok to just use degreaser to clean the rocker covers up?
Or do they need to be clean really well by soaking them in something for a few hours?