2nd blown oil filter gasket and coolant mixing with oil? Help with isolating the causes?

Brian VT

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All trucks I've ever seen, including all the ones at the wrecking yard, the cowl seal is just an L shaped seal that screws into the face of the cowl lip. So I'm not sure what the other one you're referring to is.
This is what came up when I did a search to try to figure out what you guys were talking about.
I wasn't looking forward to that project.

 

Nero

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Ahhhh a leak in the guts of the cowl, gotcha!

Yeah no it's just the rubber seal you gotta change. Use RTV on it and it'll never leak! I used black RTV so it blended a little better. Or use orange. I'm not your supervisor lol
 

SkylabTech86IDI

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Got the oil cooler pulled off and new cowl seal installed. Boy, that oil cooler job is a messy job! I ordered some engine degreaser to start cleaning the road grime and oil off of the block.


My valley pan collects water and will have standing water in it so I’ll need to make sure that drain hole is cleared.

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Jesus Freak

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I can tell you this much: it's a pain in the butt to squish those things back together with the new o rings. I can't remember how I did it.
 

IDIBRONCO

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I can tell you this much: it's a pain in the butt to squish those things back together with the new o rings. I can't remember how I did it.
I use a ratchet strap wrapped around both ends to hold tension on the caps and then I use a deadblow hammer to tap them together.
 

Old Goat

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Some people, including myself, have had success buying a roll of “L” shaped garage door seal and making our own cowl/hood seal. It was much cheaper and works great
Exactly, This is the stuff i bought, and from this site.
I bought enough to do 4 trucks.

I cut off the top broken part off the Ford seal.
Used the lower part as it is actually a metal strip with the rubber on it. Also has the hole for the screws to attach it to the Cowel.

I cut the new rubber piece to length.
Laid the Ford piece on top, lined it up just under the new flap seal section on a 2 x 4. Screwed it down in the screw holes. Then cut off the excess lower part of the new rubber.

Used some longer screws to attach it to the body.
one thing, the 87 and later trucks have a curved cut out section for the Wiper Motor. May have to cut and modify to fit that part.
Start the screws and leave it a bit loose, so you can squirt some sealant (RTV?) along the top edge so water does not leak behind it and onto the Air Cleaner.
Tighten the screws and you are done.

On my 86, I replaced the cowel with one from a 87 I got from PNP. Later one`s only have the small holes instead on the long slots for the air intake and leaves and other debris.
I didn`t really notice this when I was screwing it down and wondered why I had a hump in the Wiper area.
I looked at the old Cowel and the new one, and finally the light came on as the difference.

I also had the 87 Cowel Sand Blasted, and repainted it.

Goat
 

Old Goat

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I used Nick`s site also when I was searching on how to replace my blown OC about 4 years ago.

It really helped me along with other searching on how to do it.
Will have to remove the Oil Filter, and I think Drain the Coolant. Don`t need to drain the oil as I sits down lower in the Pan. But if you have oil in the coolant, then every thing needs to be drained and a whole lot of flushes with soap etc...

Getting to the Cooler front 4 bolts is a pain.
I finally removed the L/F Wheel, Battery and all the goodies on that side and inner Fender Liner. Then the 4 Bolts are looking right at you.

Will need to remove the left Engine Mount bolt and rise the Engine and shove a piece of 2x4 for it to sit on. Cooler slides out to the rear.

After ya clean up the end caps etc... putting it together, I used a 20 ton Hyd press, and did one end at a time. Used Syl-Glyde for the lube so it pops together.

Goat
 

SkylabTech86IDI

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What I suspect is cause of the blowing of the oil filter o-ring is this regulator is stuck. You will have to pull the cooler to get at it, in the rear head there is a staked in bit you have to get out with say a chisel. At this point you might want to think about replacing the o-rings for the cooler if you dont know there age. When this valve is stuck closed it can fire off oil fillers and cause high oil presure.


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I’m assuming that this part here is the oil pressure regulator? And that the chisel needs to go in here to unstick it?

How do I know if the pressure regulator is in the right position?
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SkylabTech86IDI

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Update: Oil cooler was rebuilt and reinstalled but the truck has mostly been sitting since the reinstall.

The new cowl seal has been installed.


today I was working on getting the glowplugs working, and the truck surprised me with more milky oil and another blown oil filter gasket.

Does this mean it’s time to do a head gasket job on this?
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SkylabTech86IDI

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I put 7+qt’s of mixed weight (but mostly new/new) oil into the motor.

I saw that the advice given so far was that it is unlikely to be cavitation and also unlikely to be head gasket.

I’m guessing that it is unlikely to be cavitation because of how easy the 7.3idi still Cranks.

Further, I’m guessing that it’s likely to be a head gasket because I’ve already rebuilt the oil cooler, meaning the last culprit of water in oil is either head gasket or block. If I’m on the wrong path, please let me know.

Head gaskets usually fail when there is an overheat condition and to my knowledge there has not been an overheat condition.

Maybe I sheared a o-ring during reassembly of the oil cooler, but I was very gentle and used lubrication and a shop 12 ton press.

Feel free to add your own experiences and/or advice.
 

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SkylabTech86IDI

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On the bright side, the glow plug bypass solution works great, so that’s a huge to-do item that’s been crossed off of my list
 

Jesus Freak

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I'd say head gasket. It would hydrolock with cavitation, at least mine did. I'm sure you did fine with the cooler, but there is that chance. You might have to go the distance, man.
 

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