Hammerhead

I just drove my baby ('83 Euro) from Houston to NC. Everything went fine until approximately 50 miles from home. I started to hear a whistling sound and I noticed that the car was now running leaner than normal.

I searched the archives and determined it is probably a vacuum or intake leak. None of the vacuum hoses have been replaced, so I decided to remove the upper intake and replace all of the vacuum lines and intake runner boots.

During disassembly, I found oil in the intake runners and intake runner boots. I decided to look down the throttle body and found a small puddle of oil.

I don't think any oil should be in the intake manifold. Is this normal? If not, what do I need to do to fix it?

heinrich

Famous cam brearther hose oil ingestion .... no-one really knows what to do about it. It's worse in some and better in other 928's. If you search you will find bazillions of posts on it. Consensus seems to be that you can solve it with a dry sump - or mitigate it with aftermarket oiling or live with it.

heinrich

When severe, it will cause the dreaded 2/6 rod bearing failure as a result of starvation ...

Hammerhead

Is it not from oil venting from the crankcase? If it's from the cam breather hose, then couldn't we just vent that hose into something other than the intake?

hacker-pschorr

I just took apart my intake, the runners were coated with oil (95,000 mile's worth of blow by?) and the throttle was stained with a layer of oil as well.

ErnestSw

Heinrich,
I don't think it's related to the starvation issue. I think the worst that will happen is fouled plugs. That's why it's good to "exercise" the shark regularly.

bcdavis

There is a hose that runs from your oil filler cap, to the intake manifold.
The idea is to vent the crankcase pressure, and gasses, back into the intake.
But when you really get on the throttle, the oil gets all vaporized, and ends up getting sucked into the intake as well as the gasses. Which is not good. If the oil misting is mild, Devek sells an oil baffle setup, and check valve, that helps reduce the amount of oil that will get in there. In my case, and with some other people, the problem is that the pressures in the crankcase cause old seals to leak, and it can be a constant problem with small oil leaks, not to mention the oil in the intake. So some people have taken the hose, that runs into the intake, and run it to a breather can, or the fenderwell, etc. And capped the inlet to the intake, so no oil or gasses will get injested. Check the archives for all the options. The problem is what to do with those venting gasses, and sometimes oil, when you are no longer running it back into the engine... Catch cans, and breathers, let out stinky vapors. I think Porken's venting to the exhaust is the way to go. Although not smog legal. I would try Devek's baffle, and see if that does the trick. If not, try some of the more extreme options as a last resort.

Hammerhead

Upper oil filler hose = vent from oil filler to intake?
Lower oil filler hose = vent from crankcase to oil filler?
Is this correct?

When I installed a ram air on my Impala SS, I removed the crancase vent hose and installed a K&N crancase vent (approx. $15). I'll probably do the same here.

Thanks.

bcdavis

The top hose is the one you want to deal with.

It goes from the oil cap to the intake. You will need a rubber hose cap for the intake fitting.

If you are going the breather route, be aware that you *may* get a lot of vapors.
Try mounting the breather farther away, to minimize this. Maybe up by the radiator,
or in the fenderwell. I still think venting to the exhaust is the way to go...

heinrich

BC I suppose given the choice of venting to the intake or exhaust .. I'd choose the latter

2V4V

Just a thought...

I would be cautious if venting to the exhaust. Sending a much larger quantity of oil vapour to the cats would probably accelerate the degredation of said device.

Yes, oil already exits your engine through the cats, but I guess it would worry me a bit to greatly increase the volume through them.

Any cat convertor engineers, please chime in on this. Perhaps the temps are high enough in the cat where the much colder crank vent gas is not a problem. Maybe I'm being overly cautious.

Greg

PorKen

Vent after the cats, but especially, after the O2 sensor.

I have mine plumbed in right after the muffler (in place of the cat) because I couldn't fit the pilot tube and one-way valve any closer to the engine.

I imagine that you have a lot of oil, the farther back, the better, where the exhaust is cooler, and won't create smoke.

SharkSkin

I think the example I saw was downstream of the cats. Either way, you can put one wherever you want and FWIW I agree it's better to either burn it through the intake or vent it aft of the cat. Though the 'glass in your muffler will eventually fill with oil...