390 Oil Problem

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Mar 10, 2005 | 06:02 PM

EarlDale'sFords

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390 Oil Problem

I have a 69 F250 with a 390 in it, and I'm having some oil isssues. Engine only has about 20,000 on it and has had no problems so far, but suddenly its been losing a lot of oil. Three times now it has run down far enough to make the engine start rattling, but I never saw any major oil leak anywhere in my driveway or in any parking lot, except for maybe a few tiny dribbles. This time, when I was putting oil in it, I put in almost 2 and half quarts, and noticed that all of the FRESH oil was leaking right onto the ground, from somewhere in the rear of the engine. Can anyone give me an idea of exactly what the problem might be, my guess is that it is leaking from somewhere on top of the rear seal so that it doesn't leak when its parked but only leaks when the oil is completely full or when I'm driving. Any other ideas?

Mar 10, 2005 | 06:49 PM

rusty70f100

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From: Iowa

Sounds like valve cover gaskets. The fresh oil gave it away. Have you got the stamped steel ones? Those are notorious for leaking. A set of aluminum ones will fix things up nicely. DSC has nice looking Ford Racing valve covers for about $110.

Mar 10, 2005 | 08:46 PM

ford390gashog

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From: Brentwood,CA

yep sounds like valve covers they only leak at high rpms or when filling the engine because it pumps so much oil up there

Mar 10, 2005 | 08:52 PM

plowpusher

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From: lino lakes, mn

is the bottom of the truck covered with oil? valve covers, back of intake manifold in the valley seal area or mabye a cut rear main seal wash the motor get a mirror and spend sometime looking

Mar 11, 2005 | 09:37 AM

FalconStng

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my 390 had major oil leaks as well. The valve cover gaskets were a big part of the problem. They can be made to seal but I agree that aluminum valve covers is the way to go...I've already purchased the ford racing ones myself. I also discovered that the oil dipstick tube had a major crack at the base of it that allowed alot of oil to leak out when the engine was running.

Mar 11, 2005 | 10:43 AM

rusty70f100

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From: Iowa

If it winds up on the ground when he pours it in the valve cover with the engine off, where else is it going to possibly come out? Really? Unless he left the drain plug off.