Coach62

1967 327 with 50K miles, to my knowledge the mileage is accurate and the engine has never been apart.

Ok, so when I dropped the oil pan in the bottom was a light to medium gray gooey gunk that resembled not quite dry caulk. It was very thick and the only way I could get it out of the pan was brake parts cleaner, even then it did NOT want to come out.

Pulled the main caps to inspect bearings and drop the crank a bit to get out the rear main seal, and this same color liquid came dripping out of the main cap bolt holes. I removed 4 caps, this came out of all 4 bolt holes, more on the drivers side than the passenger side. I would say that at least a tsp, maybe a tbsp of liquid came out of each bolt hole.

The liquid behind the main caps was just that, liquid, about the consistency of 50W oil.

There was NO oil in the water and no evidence of a bad head gasket when I pulled the heads.

What would this be? There was a fair amount of it in the bottom of the oil pan that had congealed to very thick. As you can see in the pic, the stuff from the main cap bolt holes is fairly thin, unlike what was at the bottom of the oil pan.

Any ideas??

MelWff

You want the C3 thread, your asking about a C2 engine?
Why did you pull apart an engine with only 50K?
When the engine was running did you see lots of white smoke out the exhaust?
Any evidence of engine coolant in the cylinders or a spark plug that looked different?
Have you ever seen the substance that oil and antifreeze create, usually more of a brownish color versus your grey?
Was this engine using conventional green antifreeze?
No obvious signs of a blown head gasket?

68notray

Extremely common, very normal for an old motor. Some think it is lead deposits. Nothing to worry about just wipe it off.

Coach62

No to pretty much all of the above. No, I wanted the C3 forum. It's not in a Vette, it's in my 67 Camaro. I know there's a lot of knowledgeable Gen 1 SBC folks here.

Pulled the engine apart because of some wiped cam lobes, shoulda mentioned that. Running rough.

Also leaking oil from everywhere so I wanted to replace the rear main seal.

The oil and antifreeze, yes it was green, looked just fine. Did not blow white smoke, but did blow blue after setting for a while.

Had the original steel shim head gaskets, no evidence at all of anything wrong.

I guess some of the pistons look cleaner than others.

I think I threw the gaskets out already, I'll double check.

But - how the hell would that gunk get behind the main cap bolts? Do they extend into an oil galley?

Coach62

Ok, thanks. Why would it be up in the main cap bolt holes? Do they extend up into an oil galley?

68notray

Not kidding guys, you're talking to an old machinist - I worked out of high school in a machine shop and there was always the gray lead looking deposits especially under the main cap bolts when we did a teardown.

Coach62

Now I'm wishing I wore gloves when I scraped out the gook LOL...

But then again, we did typesetting in school when I was a kid, real lead type, no gloves, right before lunch.

Now that I think about it, we were also given mercury and freon to work with in science class. Man things have changed LOL....

v2racing

I agree with lead deposits. Saw it in every engine with any miles back in the leaded fuel days.

Mike

CanadaGrant

This used to be common back in the 50's, 60's and 70's with oils with high paraffin content, leaded fuel, not the greatest of filters and if it sat for extended periods of time between runs. It's a pale gray looking clay/putty and once it settles to the bottom of the pan the only way to get it out is remove the pan and literally chip and scrape it out. You only see it now on old original engines from that time period as most have been rebuilt or scrapped since the days of that wonderful old oil... Oil would wick it's way up the main cap bolts and the deposits would settle out but it was like a layer of partially dried cement on the bottom of the pan.

7T1vette

If you didn't get a spoon and eat that stuff, you aren't in any danger.

[Jeez...When I was a youth I used to play with mercury--put some on a gold ring and turn it silver; then wear it till the stuff wore off. And look at me.......I'm fine!]

oldboat

could be lead, but i am thinking it is the old aluminum based never seize

ben dover

Condensation and lead, and yes we used to rub pennies with mercury to buy dime cokes at the drive-in. Dated myself didn't I?

68notray

Yep - I used to have a "ball" of mercury the size of a 50c pc that we would play with in school hahahaha

L88Plus

I've torn down a handful of big blocks and the stuff under the main bolts can be stanky, a lot like diff fluid.

Pop Chevy

That's a non issue. Put er back together drive it and smile !

cv67

get some heat in that motor youre just fine
our 00 e320 does the same thing
Short trips sits +cool weather

Priya

Back when my husband was in grade school they gave all the children a product of Ontario - a little block of asbestos on a cardboard card. The kids were all playing with it and getting a kick out of how you could pull stringy threads off of it.

usmilret

I am speculating that a prior owner placed an additive in the engine.

7t9l82

I agree that grey stuff isn't anything to worry about.
I understand checking bearings one at a time but I wouldn't lower the crank to change the rear seal. Just remove the rear cap and give one end a push and grab the other with pliers .

beautimus

the gray putty like stuff is what thread sealant looks like when it is oil
saturated. it would have been more white going in. the head bolts will have it too. originally in the early sixties the head bolts had sealant but the rest of the bolts including main bolts were dry. then later the mains had sealant also, i am not sure why. maybe it was used as lube to insure that torque measurements were accurate. but that is speculation.
that was used as a way to tell if an engine had been rebuilt back in the old days. because most people didnt put sealant back on the head bolts during a rebuild. my 2 cents