oil question

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May 12, 2007 | 09:04 PM

hsfbfan

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oil question

I have an '88 f150 4x4. It is a 351W and C6 automatic. I don't know exactly how many miles the truck has because I had a period of no speedometer working, then changed instrument panel. It is approximately 150,000 miles.

Rear main leaks about 1 qt of oil every 2 weeks. It doesn't seem to burn oil at all.

I have been running 10W40 conventional Motorcraft oil and a Motorcraft filter. Been using this combo since buying the truck about 3 1/2 years ago. Change the oil every 3000 miles or so.

I have been discussing synthetic oils with my brother-in-law who runs a quick lube place. He said he would switch.

Opinions? Recomendations? Change oil change intervals?

Any opinions welcome.

May 12, 2007 | 09:18 PM

S_Bruce

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Joined: Feb 2007

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From: Eastern Washington

You might want to look into fixing that leak first. Synthetic oil will eat your money if you're dumping two quarts a month into it.
I've got friends who run synthetic oil, and change it every 5000 miles. For me, and my older truck (1995), I'll stick with conventional and 3000 mile changes. Its just not cost effective with over 120k miles on the engine.

May 13, 2007 | 08:51 AM

t4kne

Senior User

Joined: Jun 2003

Posts: 176

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From: Massachusetts

If you don't want to replace the rear main seal, throw in a can of seal swell with your oil. I've never used it but have heard others say it worked for them if the leak is minor.

May 13, 2007 | 09:14 AM

Diesel Man 03

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Joined: Jan 2006

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From: Wisconsin

I would not put syn oil in there because with your oil leak I think it will get worse.

May 13, 2007 | 10:27 AM

arctic y block

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From: Island Southeast Alaska

I don't remember but if ya can get a two piece rear seal ya can replace it without pulling the engine. Drop the pan, loosen the mains (a good time to inspect one or two for wear) And roll in the new one. Be sure it's not a more common valve cover or intake leak running down the bellhousing and looking like a rear main. Easy mistake to make. And hard to spot if ya aren't looking for it. Also have seen just the rear pan seal do this as well. If compression is good with that mileage I would pull the engine, replace all main and rod bearings, Gaskets, seals and a timing set. And ya should be good for another 150k if ya don't overheat it and collapse the rings or burn a valve. A Windsor can go 300k with proper care and good driving habits.

May 13, 2007 | 10:59 AM

adrianspeeder

Mountain Pass

Joined: Dec 2005

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From: Dover AFB / Harrisburg PA

If it's leakin' yer just wastin' money with a full synth.

Adrianspeeder

May 13, 2007 | 11:21 AM

quicklook2

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From: Lakewood, Ohio

Quote:

Originally Posted by hsfbfan

Rear main leaks about 1 qt of oil every 2 weeks. It doesn't seem to burn oil at all.

I have been running 10W40 conventional Motorcraft oil and a Motorcraft filter. Been using this combo since buying the truck about 3 1/2 years ago. Change the oil every 3000 miles or so.

I have been discussing synthetic oils with my brother-in-law who runs a quick lube place. He said he would switch.

fix the leak.

stay away from synthetics.

good rule of thumb, do not listen to any advice from anyone at 'quick lube places' even if it is a relative.

you are really changing the oil more often because you are leaking and adding so much.

Last edited by quicklook2; May 13, 2007 at 11:23 AM.