Jeff

That doesn't sound good at all. Are we talking chocolate milk? Or just a bit of froth on the top? Condensation from an engine that doesn't properly warm up, or vent itself can get some froth on it. But if the oil is thoroughly mixed with water, that was not caused by running your oil just a bit too long. You have a blown gasket best case.

Does it smoke? Does the exhaust smell sweet? Does the heater work correctly? Does the engine run warmer than it used too? A cooling system pressure test would likely give you an answer. Sometimes just pulling the sparkplugs will tell you. One or more spark plugs much cleaner than the rest. (Steam cleaned appearance).

 

i agree with fenders, if you got "chocolate milk," youve got bigger problems than how many times a year you change the oil...

 

Gah.... I plan on checking the plugs tomorrow, will see what their condition is. I need to go back and check, but I think they are about a year old. I can't remember right now if it resembled chocolate or coffee, just remember it looke nothing like good oil. Unfortunately I've already mixed the old oil with oil from my car (changed it a few weeks ago).

Just out of curiosity, could this also be causing it to run rough, especially at idle? I've been trying to diagnose this problem as well, and adjusting the carb doesn't seem to have much effect (I'll admit this is my first time diddling with the carb, but I think I could get something). I thought maybe the spark plugs could be the problem, and was going to check them anyway.

 

"Just out of curiosity, could this also be causing it to run rough, especially at idle? I've been trying to diagnose this problem as well"

Jeff

It absolutely could. A blown head gasket or cracked block or head can have many symptoms. You won't necessarily have them all. Degree of symptoms will vary with engine type and how bad your leak is. The ones most commonly noticed are:

1. Rough idling
2. Engine runs hotter than usual. Sometimes MUCH hotter.
3. Heater blows much cooler than usual.
4. Coolant usage
5. Water in the oil, sometimes oil in the radiator.
6. Upon cold start up, radiator gets pressure long before engine is warm. Antifreeze may be bubbling immediately after starting if leak is bad.
7. Spark plugs get washed clean in affected cylinders. I.E. 6 plugs normally sooted, 1 or 2 plugs clean, and sometimes even tinted the color of your coolant.
8. Exhaust smoke/steam. White. And ethylene glycol (antifreeze) often has a distinct sweet aroma when it comes out the tailpipes. (He's back on that smell and taste thing again. Sorry, but I use those senses often. It was only partially tongue in cheek when I said to taste your oil).

Easy way to diagnose if sparkplug read is inconclusive. Get a cooling system pressure tester from the local discount parts house. (probably free) Remove all the spark plugs. Pressurize the cooling system. Easy on the pressure if your radiator is not in known great condition. 10# should get the job done. If the pressure goes away quick, pump it back up again a few times. Have an assistant crank the engine over while you observe the cylinder heads. It could be subtle, or you may get an shower. This isn't going to find a crack that is leaking into the oil pan, but you have a rough idle too. This points to a leak into the combustion chamber.

Keep us posted.

 

OK, I spent some time out doodling in the garage. I checked the newly changed oil, and it looks the same as when I put it in the engine (2 months and maybe 10 miles ago, with say another 30 minutes of idling total). I checked the old oil, which I will mention was diluted with old oil from my car. My description wasn't accurate -- the oil is not milky, just very dark and shiny. Not quite as dark as ink, I'd guess. I couldn't notice any special smell and ah... didn't bother tasting it.
I then pulled each of the spark plugs and examined them. They were all very black and dry (carbon fouling -- I read up on it), with the two middle on the passenger side cleaner than the rest but still kinda mucky. I cleaned them with a wire brush and reinstalled, then drove the pickup around the neighborhood (maybe three miles, enough that the engine was warmed up well before I returned). The truck seemed to run better at first but went back to idling rough, accelerating was strong but running at constant speed (~30mph) sounded kind of gargly. I checked the exhaust when I got home and it was clear with no discernable smell. After letting the engine cool a bit I checked the plugs again and they were back to the same situation I described earlier.
Oh, I also checked the coolant in the radiator. Level was good and color was also. And as I drove around the temp went up and stayed normal.
So.... where from here? Other than that I can't seem to tune a carb to save myself...

 

Jeff, are you running the stock flatty in your rig? That would open up a lot of possibilities for your oil condition.

 

Jeff

We'll this oil description sounds like good news. Don't stress black oil. Do you have a local mechanic friend that can drive it and offer suggestion? I won't pretend I can fix it over the net, since I really don't know what you got. I can offer a few basic suggestions.

Don't beat yourself up because you can't tune a 50 year old carb that might be full of debris. I rarely do much to the carb until I have verified the entire ignition system is in excellent repair, and the engine is in reasonable condition. Decent compression, no vacuum leaks etc. You can really end up chasing your tail if you dig into a carb and try to tune it to work with a faulty ignition system.

I'd start by verifying the distributor shaft isn't too sloppy, install new points (unless they are very new) and set the timing. Check plug wires, coil etc. There are guys here much more competent on the flatties and Y-blocks than I. Start a new thread if you need to. A lot of people are probably skipping over this one at this point.

 

I felt a little better last night after working on the truck and feel a lot better now. I had been debating for several years whether or not to have the engine professionally rebuilt (ounce of prevention type of thing, if nothing else) but I'd rather do it by my own decision. The thing that gripes me about the carb is I had it professionally rebuilt about a year ago and it worked great for a couple of months, then started making a clunking sound when operating the throttle. I took it back and they worked on it some more. Unfortunately it hasn't run right since and I loathe taking it back there again. May go down the street where I had some work done early on.

I agree this thread has gotten rather long and way off subject. Thanks for all the help, I'll start a new post when I get more news, good or bad.

 

Jeff...you probably already know this but make sure your choke is opening all the way. That will make your carb rich and turn your plugs black. Oops, I was going to get into enrichment screws and power valves, then I realized you have a flathead v8. So I better quit, but check the choke.

 

If plugs are carbon fouling in such a short distance you're most likely running rich.