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300 6 cyl coolant passages

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Scott Griffin

300 6 cyl coolant passages

Recently picked up a 80 F350 and was adding coolant when I noticed it pooring out from an area at the back of the motor under the exhaust manifold. It was hard to see but looked like a fitting had been removed. Is there an illustration to look at?

Gary Lewis

Re: 300 6 cyl coolant passages

Administrator

Illustrations are here: Engines/300 Six. There should be soft plugs in the block in roughly that area. Something like 2" in diameter.

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

Scott Griffin

Re: 300 6 cyl coolant passages

THANK YOU

85lebaront2

Re: 300 6 cyl coolant passages

Administrator

Temperature sensor could be missing, I believe it is near that area also.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

1986F150Six

Re: 300 6 cyl coolant passages

Administrator

Yes, Sir, it is located just under the exhaust manifold between the #5 & 6 cylinders.

Steve83

Re: 300 6 cyl coolant passages

Banned User

It's behind #6:

85lebaront2

Re: 300 6 cyl coolant passages

Administrator

Thanks Steve, I thought I remembered that being correct as to the location.

Bill AKA "LOBO" Profile

1986F150Six

Re: 300 6 cyl coolant passages

Administrator

In reply to this post by Steve83

Steve83 wrote

It's behind #6:

Thanks for the correction!

PetesPonies

Re: 300 6 cyl coolant passages

In reply to this post by Scott Griffin

So it probably is a core plug leaking. The core plugs ( people incorrectly call them freeze plugs ) were there so that the sand cores can be removed once casting is complete. A metal plus is pressed in and evidentially they rust and leak. There are "temporary" rubber plugs you can use, but best is to get a new metal plug back in. The hole needs to be cleaned, even sanded a bit. Then some sealer applied to the plug and hammered in using something like a large socket to spread the force around the out edge. Once i tis started, you can more easily tap it around the circumference until it is flush. Don't go too far :)

Pete's Ponies
Mustang RUSToration & Performance

1982 F100 Flareside
1983 Bronco

85lebaront2

Re: 300 6 cyl coolant passages

Administrator

I may be thinking of a different in-line 6, but are there some small core plugs on the manifold side of the head?

Bill AKA "LOBO" Profile

Steve83

Re: 300 6 cyl coolant passages

Banned User

85lebaront2 wrote

...are there some small core plugs on the manifold side of the head?

85lebaront2

Re: 300 6 cyl coolant passages

Administrator

I know about the ones in the block, I haven't worked on a 6 in a number of years and didn't think there were any but couldn't remember if any were on the head. Must have been either GM or AMC I remember having some small plugs there.

Bill AKA "LOBO" Profile