Thread: leaks oil....a lot.

Originally Posted by bee utey

The tee piece and restrictor jet are important to prevent fumes being drawn through the IAC (stepper) motor, eventually clagging it up. Good thing you got an o-ring for the dissy, I have seen some people cut paper gaskets for under the dissy too, similar to old Holden red motors.

You can make your own tee, like:



remembering the restrictor jet to the manifold is important.

Well, after a few weeks with minimal leaking it came back again during a trip away . 2.5L of oil from Gosford to Tamworth....at least the gearbox, transfer and rear diff is now well rust proofed .

Anyway, the leak was mainly from the breather in the LH rocker cover. Cleaned the throttle body and the orifice just forward of the butterfly was blocked, as was the tube fitting for the hose that goes to the purge canister. Mine didn't have the tee as above (its a 3.5 flapper) so i raided one from the 'spare' 3.5 hotwire D1 and fitted it. The orifice in it was 7/64" (2.75mm) drill size. It was plumbed in closer to the flame trap, into a spare plug on the RH side of the inlet (between brake vac and extra air valve fittings).

Now i seem to have excessive vacum in the crankcase at idle. When you remove the oil filler cap with the engine running, there is noticable suction on the cap, and you can hear the valley gasket 'pop' when you remove it. With the cap on, you can also hear the gasket pop when you shut the engine off.

Should i reduce the orifice size to 1.5mm or just remove it compleatly.

Cheers
Rick

Made a new breather tee with a smaller 1.5mm orifice and all seems well.... for now. When you think about it, the 2.75mm orifice had nearly 4 times the aera of a 1.5mm one, a pretty big jump up in size.

It dosn't seems to fume excessivaly and i think my main problem was the blocked hole in the throttle body (linked to the large breather hose). What size should this be?