Slow Oil Leak

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Slow Oil Leak

mattmo
Hello,

Did some maintenance on the truck today. While down there I noticed the oil pan was extremely grimy. I tested all the oil pan bolts, all I could reach were snug. I drained the oil and got about 3 quarts. Up to this point the truck has had 0 leaks. I added 6 quarts of 5w30 synthetic blend and noticed slow leak. After about an hour there was a few drops on the driveway. I'm wondering if the leak is above the oil pan, when the oil got down to three quarts it may have no longer covered the area that was leaking.

I got under the truck and noticed it seemed to be seeping from under the engine cooling fan. Picture below. Please forgive the bad angle and quality, hard to get my hands down there.


Any ideas on what could be causing this?

Thank you,
1985 F-250 4x4
128k miles
351w
Warner T18
Dana 61 Rear 3.54
Dana 44 TTB HD
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Re: Slow Oil Leak

Gary Lewis
Administrator
LOL!  The angle is such that I haven't figured out what I'm looking at.  However, the front main seal where the crank comes out of the pan/block combo is a frequent point of leakage.  And when it leaks the oil is thrown to the passenger's side as well as is blown back along the pan.

So is the passenger's side inner fender and the alternator gooey but the driver's side is clean?
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

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Re: Slow Oil Leak

ArdWrknTrk
Administrator
Gary,
You can tell the larger pan bolt is the one going into the timing case.
So, I agree, it is the FMS.

Pulling the timing case can be a can of worms, because corrosion of the passages, questionable rubber in the harmonic damper, and the "while you're in there" aspect of the timing chain and water pump.

A gasket set with a SpeediSleeve is not much more than a regular timing gasket set, and you're assured of a leakproof seal.
 Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.
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Re: Slow Oil Leak

mattmo
In reply to this post by Gary Lewis
Very weird, I pressure washed the engine today. Cleaned it with brake cleaner and waited for it to leak again. Nothing. It seems like it stopped leaking entirely, for the moment at least. I guess at this point all I can do is continue to monitor it. Thanks for the tips!
1985 F-250 4x4
128k miles
351w
Warner T18
Dana 61 Rear 3.54
Dana 44 TTB HD