Thin oil?

[DCAlbarran]

Well, finally got the brakes mostly sorted out. Now starting to go through the engine and figure out why I seem to have a pretty good oil leak, especially when running.

The one 20 minute drive I took her on, she was pissing water from either the bottom of the radiator or a hose by the end, and has had a persistent oil leak at the rate of a drop every 5 seconds or so when running and after being shut off, continuing for about an hour. Water ran clear, with no signs of oil or other contaminants, so I refilled the radiator with 50/50.

When I checked the oil, the dipstick read overfilled by a significant amount (maybe a couple quarts), and when I drained the oil, it seemed super runny and thin, but normal colored. Also more then the 5 quarts or so I was expecting (I haven't looked up the capacity yet). I reserved some in a clear container to see if it separates. My plan was to change the filter, fill with fresh oil and coolant, and see where we are at, but I don't have a spare filter, so it'll have to wait a couple days.

Question is why would the oil seem so runny? My initial though would be head gasket, but the coolant was clean, and the oil color was good. Also the truck didn't seem to be overheating. Truck has been sitting for 8 years or so.

Thoughts?

 

[DomSmith]

What year again? Do you have the original canister style filter or a regular screw on?

Can you see where the oil leak is from underneath? Area of leak (front middle rear driver passenger) would help with pinpointing the source. If you’ve got the original canister style the area where the bolt passes through the canister is a common spot as are the oil lines if they’re old.

Some pics might help. I like to use the app Stitch to make arrows on my photos to help identify what I’m talking about.

No real point in refilling any fluids until you sort out where the leaks are coming from.

 

[DCAlbarran]

It's a 1963 FJ45. It's been upgraded with the screw on filter relocated to the firewall. Leak seems to be coming from the rear area of the engine, almost where it mounts to the trans. I wonder if the leak is from the oil being so thin? I'd like to put known weight oil in, along with fresh coolant and a fresh filter so I can find out if the two are mixing in the crankcase.

 

[DomSmith]

If it’s at the rear it’s probably the rear main seal or the oil pan gasket if it’s the 4 piece type that needs RTV to keep it in place. Very common to come apart and leak there. Easy fix.

Are you sure it’s motor oil and not gear oil? When I first got my 65 the front of the 3 speed was leaking. It should be easy to determine which but you might consider draining tranny and trans and putting new gear oil in anyway. Either way if it’s in front of the bellhousing then it’s oil.

 

[DCAlbarran]

As far as the leak goes, its definitely not gear oil. Way too thin, I am thinking.

 

[Splangy]

Does it smell like fuel?

 

[DCAlbarran]

I'm home tomorrow, I'll take a whiff.

 

[Vintij74]

There’s a thread about the same sort of thing where the guy was filling up WAAAAAY too much oil & it turned out to be a plug by the valve lifters and it was just pouring into his oil pan..Good luck with finding the source!
Hope it’s not your cam plug & just a rear main.....
Back to Alabama vs Georgia game!!

 

[DCAlbarran]

Does it smell like fuel?

Update: does not smell like fuel.