I noticed today that I had a milky yellow sludge in my oil on the '60. I've seen this type of sludge before but never this amount of it. I was told at one time that it's a result of water in the oil so I'm a little afraid that I might have something bad going on in the ol' Y block. I have had the truck for about a month but today was the first day this was present.
I changed the oil, but there was a lot of this left in the filler tube and on the dipstick.
Anyone know what it is?

 

look like peanut butter? That would be anti-freeze and oil, straight water and oil gives a grey mix. Possible places to check: intake, front cover, etc.... We are talking alot of this sludge right?

 

Do you run a PCV setup, or just the stock draft tube? Since this appears to be a new thing for your engine, is it possible you've just not gotten it fully warmed up since the weather turned colder? Condensation can cause this if you don't ever get the engine up to 180+ for an extended period to burn off the water.

 

I'm with ALBUQ F-1; mainly because you bring it up this time of the year. it's the same reason sometimes water drips out the tailpipes when its very cold out. after running, while cooling down it draws moisture out of the air.

i'd check all the stuff mensioned, PVC, crankcase vent/breather.

my 84 dodge 318 gets it in the dipstick tube every winter (and goes away every spring)....but that motor has 200,000 + miles.

 

Antifreeze was my first thought but the temp gauge looks good so I can't imagine it is mixing or wouldn't it overheat?
I had completely forgotten to mention that it does have a PCV valve. I noticed this sludge in the oil breather cap first- actually dripping out of it. I'll take a look at the PCV but it may just be the cold weather...I'm sure that has something to do with it as it's been fine up until yesterday.
Also, I drove it for a few hours yesterday, and probably 50 miles or so, so it should have gotten hot enough. I had wondered if the previous owner put in some low temp thermostat or something.

Thanks.

 

For sure you want to do something about it, including changing the oil. It might be worth sending a sample in for analysis if you don't find anything obvious. A small antifreeze leak won't show a temp increase until it's too late!

 

Thanks for the heads up. This engine won't be in there forever. As much as I like having a running and driving rig, if this is what it takes to motivate me for my swap, then so be it. For now, I'll keep an eye on it and see what shakes out...
Thanks to all.

 

Well, I drove about 20 more miles today, parked the truck, checked the oil dipstick and the tube and the sludgy stuff is still there. The odd thing is that the radiator cap was not hot. Every other radiator cap I've had would scald you if you touch it, but I could hold my hand on this one as long as I'd like. It was warm, but not hot. I wonder if there's a 160 degree thermostat in there because of the warmer climate in Georgia, where the truck used to reside.

 

Thermostats are $10 max, go for it. Use at least a 180. It sounds like yours is stuck open (if it's even there!)

 

Update: I just looked at the oil that came out- put it into a see through jug and there are NO traces of green or water in it. Now that I think about it, the oil wasn't even remotely hot when I changed it yesterday, yet the temp gauge showed in the middle.
I'll put in a 180 thermostat...next I'll be asking about why the gauge shows I'm overheating!

 

If you really want to know if its antifreeze in the oil..........taste it. I know, I know, it sounds awful (and it is) but I'm not meaning take a big swig. Just dab a bit on your tongue.

If there's antifreeze in there it will be sweet.

Bobby

 

Make sure you are pulling a vacuum on that PCV valve. I had a 300 six cylinder Ford engine tha the vacuum line to the PCV vale stopped up and I got the same problem you have. I cleaned the vacuum line and it all cleared up.

 

I've had yellow oil when I've had a blown head gasket, also had low water (imagine that) and no heat.......water level too low. I was wondering if the reason that the radiator cap was not hot because there was no water in contact with it.
Best Regards,
Jon

 

The previous owner thinks it has a 160 degree t-stat in it. He said that he'd noticed it before to a lesser degree (probably the way it was when I got the truck). I'll try another thermostat...if I can find one. That's for another post.