greghennings

Hey guys, was putting some final pieces back together on my l-48 that i had put all new gaskets in here the last couple weeks, and i just double checked my oil to make sure it had plenty in and i noticed it was kind of blurry. Pulled the drain plug and took a sample and got this..



The first thing that came to my mind, antifreeze. How the heck is antifreeze getting passed my brand new gaskets . So the first theory is head gasket. I ran the motor for several minutes watching the radiator for bubbles. Thermostat opened and closed fine, there were some bubbles, but not big ones, like tiny tiny and like maybe just a couple here and there as the water raised and lowered. I'm not sure yet to chalk that up to heads or if its just a small amount of air getting trapped and released in the radiator itself. Not quite yet convinced. I see i can get a test kit to check for exhaust gases in the radiator, i'll get one if you guys think i should. But it could also be my intake gaskets too....

BUT, after running the engine for a while i let it cool and took another oil sample and got this...



Hmm...my oil went from brand new to green, and from green to black with maybe 10 minutes run time on it.

So now i wonder if its actually coolant in the oil or is it gas? I know my carb is running very rich right now, is there any chance that to much gas is getting in my cylinders and not burning off? Or maybe some how gas is leaking out my carb into the engine? The green container does have a gas smell.

I'm also going to let these two containers sit over night, if there's water in it, it should seperate out...

Any ideas guys? Thanks!

'75

Ok, having been a heavy equipment mechanic for more years than I want to say, here's what I would do. . The quickest way to tell which it is is to get a little of the oil on your finger and just barely touch it to your tongue. If the mixture is water and oil, you will taste almost nothing. If it is antifreeze and oil, you will taste it instantly. Oh yea, wipe your tongue off, you don't want to eat the stuff. The other and safer way is to take about a 6 oz sample of your oil to get it analyzed. Most any heavy equipment dealer or lubricant supplier will have connections to a lab for this service. Your oil looks like it has a little air in it.

TimAT

Every time I've seen coolant in the oil, it looked like a milkshake. Unless it was so small of an amount it didn't matter.
The green looks like fresh oil that has been ran for a very few minutes and is starting to pick up some contaminants. Doing it's job. The black is after it's ran for a while and has washed out some more of the junk. The only real way to prove anything is have a lab test done like '75 suggested.
You might put a few drops off the dipstick onto a clean white paper towel. Coolant/water will make a large ring around the oil since it soaks up into the paper faster.

greghennings

great tips guys, i guess if i let jack daniels kill off my brain cells why not antifreeze?

After some lengthy internet research i don't suspect its coolant right now, all the pictures i've seen of oil and coolant are of a brown chocolate milk-shaky color. I'd almost be leaning toward what you said tim, maybe its just cleaning out the engine like its supposed to....

TimAT

Jack Daniels' makes brain cells STRONGER and BETTER LOOKING. Wild Turkey kills them.

AdamMeh

Always wise to use pure water for the initial fill. Better to have water in the oil than antifreeze. Instead of head gasket(s), a very common place for SBCs to leak is the intake to head coolant passages. Leaks down into the lifter galley and you can't see it up on top.

Hope you get it figured out and it's not to serious.

Adam

Doug1

maybe an intake manifold not totally sealed up properly, ask me how I know....just like Adam pointed out

cv67

Normal for some of them to turn that greenish color. Black probably just some unburned gases. Run it.

greghennings

i'm hoping not to have to dismantle it again, but if it has to be. i'm using Pennzoil and its decently price by 5 quarts, maybe i'll just fill it up again and run it and see what it looks like...

So adam you would suggest starting with distilled water first? Then empty it out and then add antifreeze? Just for future reference....

ramair_bryan

Put the sample in a coke bottle, tape it really good to the bottom of the wash machine.
Spin that dude for 10 min or whatever........remove it and examine the sample before it joins back together. Oils the lightest. water mid, metals heaviest May even separate the oils ingredients by weight. ps......use the neighbors machine...................

tnovot

Quote: So now i wonder if its actually coolant in the oil or is it gas? I know my carb is running very rich right now, is there any chance that to much gas is getting in my cylinders and not burning off? Or maybe some how gas is leaking out my carb into the engine? The green container does have a gas smell. Quote

Not sure what year your engine is. Unless you have an electric fuel pump, gas can leak into the crankcase through a bad mechanical fuel pump diaphram.
Terry

AdamMeh

Hey Greg,

I would recommend using straight water for the initial fill. Antifreeze will eat bearings, but water alone won't. Just good practice when working with a new motor or even a top end rebuild.

Adam

greghennings

i do have a mechanical, i hope that's not it....if i have to take it off, even to check it, is it possible to get an electric one in its place?

TimAT

Fuel is easy to find in the oil- use the dipstick and a lighter. Pull the stick and hold a lighter under it. If it flashes, it has gas in it. And it's a small enough amount that it won't blow up.

7T1vette

Uhhh....use a lighter to check for fuel in the oil???

How about just sniffing it? You can easily smell gasoline in the oil...if there is any significant amount. Also, if you let the oil sample sit quietly for 10-20 minutes (or overnight), any water/antifreeze in the oil will settle to the bottom.

Did you slop a lot of assembly lube on the cam/moving parts when you assembled the engine? That may be the black color you are seeing.

SuperBuickGuy

condensation might be your issue.

I had a jet boat with a 472 Caddy motor in it... every spring, first fire - milkshake, run for a bit, cleared up and worked just fine. Head gaskets don't heal themselves - so I suspect either you have jokers around you like I do (bastard jokers to be specific), or you've had a cycle of hot/cold plus humid days...

greghennings

well that is also highly possibly. we did go from 10 degrees to 50 deg in a matter of a couple days here. Now that you mention it the exhaust was spitting out quite a bit of water.

greghennings

here's where i'm at with my own lab work

nothing separated overnight, not even a little. I don't know how well gas would seperate out of oil, i would guess it doesn't and if it does it probably evaporates as it does. So it looks like water is out.

paper towel test suggested left no definable ring, one even blotch.

lighter test, oil did not flash, only sizzled. but doesn't rule out gas, might not be enough of it mixed in.

left my oil tray under the car over night to see if any fresh separated water would come out of the oil pan, like leave droplets in the tray, no such luck.

taste test tasted like nothing, but my sense of taste is poor.

With the vial cap on for a while, and the removing it and smelling it right away, it smells like ethanol to me.

i didn't really disassemble any moving parts, pretty much just replaced head, intake, oil pan, rear main seal, exhaust, timing cover, valve cover, water pump, and fuel pump gasket.

i think maybe later today i'll run another batch of oil through it and see what happens...

Doug1

starting to lean this way myself now

birdsmith

Your engine contains and/or processes three kinds of fluids- oil,water/coolant,and gasoline. I didn't see you mention what kind of carburetor you have...I have personally experienced my own Holley spreadbore siphoning three quarts of gasoline into my oil overnight.If your needle/seat are leaking this can happen; it can run through the carb, down into the cylinders, and past the rings down into the oil pan. Drip,drip,drip. If this is happening you'll see it on the dipstick...

As for water/coolant- is there any evidence of oil in the water? THAT will produce a 'milkshake', it only takes a little oil in a large quantity of water to give it that appearance. It is generally more likely, however, to get water in the oil because the water/ coolant is under pressure when running and the places that it might leak will cause it to co- mingle with the oil (intake joint leaks, cylinder bore cracks or blown head gaskets).

Once you've figured out just what it is you've got- gas in your oil, oil in you water, or water in your oil, you can then work on how to correct the problem. Gas in oil=easy fix. Water in oil or vice versa; maybe easy, maybe catastrophic...what was the motor doing prior to the gasket change? If it wasn't exhibiting these issues before, it seems most likely that a gasket wasn't adequately sealed...hopefully that's all it is, most likely an intake leak...