Engine will not turn over

[Raymond Smith]

So, my stock M38, 24 volt system, decided that it did not want to turn over yesterday.
I have not had it running for about 6 months (I know, shame on me)
Put new batteries in it this weekend.
Confirmed 24V to ground at the battery and 24V at the starter switch.
Hit the starter pedal.
Felt the usual engagement clunk from the Bendix and nothing else.
Saw the oil pressure gauge peg over to the high side.
Hit the starter again and same thing.
Shifted everything to neutral and shorted the starter switch. Starter motor whirred along nicely.
Tried the starter pedal again and just the clunk and pegged oil pressure.
Put it back in gear and tried to push to see if the engine would turn, but no luck there as I was alone and I was not enough to move it much.
So, is my engine locked up? I doubt if the starter switch and rod got out of alignment just sitting there.
Other thoughts?
What should I try next weekend?

[dpcd67]

Pull the plugs and try again. I'll explain why later. If that doesn't work, and it won't turn if the jeep is moved, that's bad.
Run every 6 months? I have so many vehicles that once every two years is normal. But they never lock up; that is not how it works.

[Raymond Smith]

Ok, thank you.
I will give it a try this weekend, that does seem to be the most logical next step.
I hate the thought of pulling the starter for no real reason, but the alternatives might be even worse.

[dpcd67]

I'd wait until Idalia passes first.

[Raymond Smith]

Well I did wait for Idalia to pass, fortunately for my area, it was just a bit of wind and rain, nothing too serious. West of here and out to the coast really took some damage. Been trying to help out some with the damaged areas. So hopefully this weekend will have a chance to pull the plugs to see what's going on. Thanks for thinking about us.

[dpcd67]

Glad it missed you.
I just read that your starter motor "whirred"; I assume that means it turned over? And the engine didn't?
And you can't have oil pressure unless your engine is turning over; M38s have electric sending units; not direct read like other jeeps.

[fnp43]

I would try turning the crank shaft nut on the front of the engine with a socket and breaker bar I would try with the plugs out If the engine turns over its not stuck The next thing I would look at is the starter The bendix spring may be weak or not engaging the flywheel

[Raymond Smith]

Weekend update.
The saga continues.

I disconnected the battery and pushed on the starter pedal, which felt like the drive engaged and switch was making contact.
Then I removed the plugs, which fortunately came out with little trouble. (I use Champion 2612 thread lubricant on all my spark plugs)

Reconnected the battery and hit the starter. Good thing I put the hood down.
I think it was #3 cylinder was full of an oily black water (maybe some gasoline?) liquid mix. At least it "was" full, its now sprayed all over the inside of the hood and top of the engine. Doesn't appear to be any water in the oil pan, that oil is nice and clean looking on the dipstick.
Wiped everything down, and tried it again, turns over fine with no spark plugs. I am assuming that one cylinder just happened to be hydro locked and would not allow the engine to turn.

I put the plugs back in and she turned over and sounded normal. (ignition off)

So, the problem? Looking for thoughts? Cracked head? blown head gasket? Next step?

Next weekend I might pull her outside and see if she will run. I assume some of that oily mixture is now in the exhaust and intake manifold, so if it does run, probably get an awesome smoke show as it warms up.

[dpcd67]

And that is why I said to remove the spark plugs...
You have a blown head gasket, hopefully, and not a cracked head. Pull the head and see. Easy fix. Unless, you know...

[fnp43]

It sounds like a blown headgasket I would not try to start it Water does not compress and you might do serious damage You have to remove the hhead anyway so do it first and see what you have Hopefully a new gasket will fix your problem With the head off carefully look for obvious cracks in the head or block If none found put a new headgasket on and hope for the best

[dpcd67]

You also need to inspect the head for flatness; they are rarely really flat unless you have them machined.

[Raymond Smith]

I think you are right, I will remove the head and see what I am dealing with.

Any recommendations on a head gasket brand? Part Number?
Is there a gasket under the water tube?
What about using the copper spray on the gasket material?

[dpcd67]

I just use the FelPro ones that come in the kit, and are $35 if you buy it separately, that Ron sells; they are metal on one side, but some guys want the old school copper (Best brand) ones $45 from Ron, and you can't go wrong with those.
I always use copper spray on head gaskets; make sure it dries to a tacky consistency first.
Yes, the water outlet has a gasket.

[Ron D]

FelPro makes 2 heads gaskets for the L134.
Choose carefully --- they aren't interchangeable.
FelPro part numbers 7267B and 7285B.

Pretty sure the all-copper BestGasket 555C is equivalent to the FelPro 7285B.

Stock M38 head uses the 7285B (or 555C) gasket.

Advice about using copper spray is all over the page.
Follow the Army TM says no.
Follow the gasket makers instructions --- it depends who made it.
Follow interweb opinions --- flip a coin.

Most say it can't hurt anything to use it.
As long as you know it won't fix either a head or block surface that's not within spec for flatness.

[dpcd67]

Permatex copper spray was not invented when the TMs were written. And you know, I always say follow the TMs!
But, I have used the copper spray on at least a dozen engines (L134s, one F134, Dodge 230s, and one 251) and have not had a problem yet. I like the way it smells. Of course, I have the heads ground flat, and the blocks checked and ground if necessary, by Abrahams.
I don't know the makers numbers; I just order them from Ron. They come in the engine gasket kits.