Strange Oil Leaks

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fat73

Strange Oil Leaks

Post by fat73 » Sat Aug 31, 2002 6:24 pm

Ok...I'v now pulled the engine out of my '73 914 6 times over the past 5 years. The last time I did new cylinders/pistons/heads. I'm running carbs. At high speeds I get oil splattered all over the engine compartment, not underneath, INSIDE THE ENGINE COMPARTMENT. It appears to be pooling underneath the intake manifolds on the passenger side. Oil Cooler? Trying to avoid pulling it again. Any Ideas?

see

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Piledriver
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Strange Oil Leaks

Post by Piledriver » Sat Aug 31, 2002 8:09 pm

Could be the oil cooler, but it would tend to go DOWN more than out I think.

Could be the head breathers (if so still equipped)

Could just be a slightly bent valve cover not sealing at the top.
Swap them.

Take her to the car wash after dousing her real well with degreaser, and dust her off with talcum powder with the engine running--- maybe shake a little in the fan.

Just an idea...

fat73

Strange Oil Leaks

Post by fat73 » Sun Sep 01, 2002 8:20 am

Thanks...the powder idea is a good one. I'm considering going to a 911 fan conversion e.g. from FAT performance. Does anyone know if that'll fit underneath the standard drip pan.

By the way Here are some pics of my car(s). Don't have the 924S anymore..

fat73

Strange Oil Leaks

Post by fat73 » Sun Sep 01, 2002 8:22 am

ooops .... forgot the link for the pics
home.tampabay.rr.com/hunziker/docsmain.html

kevin powers
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Strange Oil Leaks

Post by kevin powers » Sun Sep 01, 2002 8:43 am

is the breather hose off the oil filler in good shape and connected? if you open the flapper boxes (pull up the lever with the red knob) when you're driving do you get an oil smell in the pass compartment?

fat73
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Strange Oil Leaks

Post by fat73 » Sun Sep 01, 2002 9:26 am

Here's the setup.
Oil breather line from oil filler to a breather box bolted to rear firewall. Breather box has lines running to each valve cover (welded on breather ports). All clamped.

New AMC 1.8 heads, New 96MM 8:1 pistons/cylinders, Scat Cam, dual 40's, balanced, high volume oil pump

Could I have an oil galley plug leaking somewhere? By the way this is only on the passengers side.

914Racer
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Strange Oil Leaks

Post by 914Racer » Tue Sep 03, 2002 10:08 am

I've been having the same problem for a while now. For me it was a leak around the top of the valve cover. First check to make sure your valve covers are flat and true. Then take the bail wire off the head and decrease the angle of the bends at the ends using a vise and light tapping with a hammer. This will increase the pressure that the valve cover exerts on the head. Unfortunately that didn't work for me.

I have a 75 engine so it doesn't have any breather holes in the heads so I put fittings on the valve covers. That didn't work either so I ended up with bolt on valve covers. They're known to leak (and they do) around the screws and sealing o-rings so I fabricated little cups to capture the sealing o-rings that come with the covers. Now no leaks! Even with very low torque on the bolts they seal up very well. If you get the bolt on covers be sure to get the 4 bolt variety as they will put less stress on your rockers studs. I'd also recommend safety wiring the bolts as they can come loose. Not a big deal on my race car but it might be cumbersome on a street car.

-Greg

[This message has been edited by 914Racer (edited 09-03-2002).]

johnrogers
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Strange Oil Leaks

Post by johnrogers » Thu Sep 05, 2002 9:37 am

You might want to try getting some clear water bottles and putting each breater hose in a bottle after you clean things off to see which one is blowing. But I suspect it is the lack of vacuum in the crankcase that is cauing the valve cover gasket(s) to blow by at high speed. The case in a stock setup has a PCV valve and some suction on it. When you switch to carbs you loose the vac source and the build up of pressure in the case can prevent oil from draining back from the heads and then pressure will build up, even if the covers are vented. Make sure the gaskets are sealed to the cover and are not moving around. Good luck.

914Racer
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Strange Oil Leaks

Post by 914Racer » Thu Sep 05, 2002 10:23 am

I forgot to mention that in another thread, Racer Chris had problems blowing valve cover gaskets on the passenger side (I think). He attributed it to the oil sloshing out of heads in hard cornering. Once the oil was gone there is nothing to absorb the heat so the gasket cooks.

I have a really crappy header system (not nearly as nice as Chris' by the way) that bunches the exhaust right up next to that valve cover. I have a suspicion the heat from my header is cooking my valve cover gasket.

-Greg

ray greenwood
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Strange Oil Leaks

Post by ray greenwood » Thu Sep 05, 2002 12:52 pm

There are two common problems not mentioned. If you have high oil pressure, and the plastic seal in thecenter of the oil pressure sending unit is cracked, it will spray oil. Also this is common from a crank seal on the fan end that has either a split o-ring, or has the lips hardened from age and leaks at high rpm oil pressure. It sprays from the line bewteen the cooling manifold and the block. Oddly enough the oil pressure sending unit leak will leave virtually no oil under the car...as it only leaks at high pressure...and for the same reason leave little on the oil cooler as well. Ray

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