Condensation in oil fill hole

[militarypotts]

What is with the condensation in the oil fill hole on top of the valve cover? I pulled out the filter screen and it was coated with a brownish watery mixture. Any comments on this would help me understand the problem. Thanks

[randygar]

This means you have water in the oil.

It could be from an easily fixable source, like fording in deep water with a leaky vent system, or it could be a blown head gasket...

--Randy

[brute4c]

Agreed.

[porkchop]

Randy said it, check your oil, is it a light brown milky color? Look at your crank case hose to see if there are any cracks or splits. Lets look at the easy things first. Most likely a simple fix.

[militarypotts]

I just drained the oil yesterday, and absolutely no sign of water in the crankcase. Never have seen any signs on dipstick either. Is it possible that the difference in temperature around filler neck, (hot engine/cooler air temps) causes condensation? The filler cap has a rubber gasket in good condition, but under the brass ring, the rubber seal is gone. I'll check the crankcase hose next. This has been a problem for some time, so I've always kept a close eye on the appearance of my oil. Definitely no milkshake look to it, or milky brown color. In fact I was surprised to see my oil as black as it appeared, being the truck isn't driven on a regular basis. Thanks.

[randyscycle]

I've seen this quite a lot on older vehicles and its pretty normal. A head gasket or other water contamination would cause the oil, as said above, to become milkshake-like.

I think the breather systems on older engines weren't as efficient at removing all the crankcase vapors and would leave a bit of moisture to collect at the oil cap or in the valve cover. It also seems to be more prevalent on engines in vehicles that sit more than they go.

Change the oil (sounds like you already did) then drive it and get it up to temperature. Do that on a regular basis and you should be fine. I doubt there is a head gasket issue if you aren't losing coolant, or don't have a presence of water mixed in the oil.

[Don Cavey]

I've seen this quite a lot on older vehicles and its pretty normal. A head gasket or other water contamination would cause the oil, as said above, to become milkshake-like.

I think the breather systems on older engines weren't as efficient at removing all the crankcase vapors and would leave a bit of moisture to collect at the oil cap or in the valve cover. It also seems to be more prevalent on engines in vehicles that sit more than they go.

Change the oil (sounds like you already did) then drive it and get it up to temperature. Do that on a regular basis and you should be fine. I doubt there is a head gasket issue if you aren't losing coolant, or don't have a presence of water mixed in the oil.

I would totally agree with the above. As stated, older vehicles don't have the same quality of gasses and moisture removal that the modern engines do. Now I know you only get 10 MPG but the truck will benefit immensely by driving it often and when you drive it, make sure that it gets up to full operating temperature, at least 10 miles (which equals about $4.50 in gas )

[randygar]

Unless your PCV valve is bad, these old trucks have identical moisture/gas removal systems to modern vehicles...

Only running the engine for short periods of time, without letting it warm up to full temperature, or without a thermostat, can cause condensation in the oil as well. Solution: drive more!

I don't have any foam/glop under the cap on my truck, so I know this isn't a design issue...

--Randy

[militarypotts]

I wish I was getting 10 mpg! Try 6 on a good day. I don't worry about the price of gas as far as driving the truck. I just don't have anywhere to go in it. It's driven twice a week to shows and such. Maybe with summer here, I'll drive it more often. It's strickly an extension of my military collecting hobby, and one that I can share with the public. The rest of my hobby, mostly rifles and handguns from WWI thru Vietnam Era is much more private as I'm sure you can understand.

[randyscycle]

Unless your PCV valve is bad, these old trucks have identical moisture/gas removal systems to modern vehicles...


--Randy

1963 technology (basically) is a bit dated. I know in theory, the PCV system in a modern vehicle is similar, as it removes unburned vapor from the crankcase and returns it to the intake to be re-burnt. Many newer vehicles no longer use PCV valves anymore, but orifice systems and a few are even controlled by the ECM as well.

Another really big factor that has a real effect on crankcase vapors or failure to remove the condensation therein is engine operating temperature. Modern cars run at temps somewhere around 220F and higher, depending on the design. That can eliminate the water vapor a lot easier than the 180-190 marginal temperature that a stock Tornado sees.

Again, I don't think it is necessarily a design issue, but an antiquated system that was probably marginal at best in its day. Also, you tend to drive your truck every day, correct? That may account for a lack of moisture/condensation in the valve cover.

I certainly have seen this many times in my 20+ years of dealing with fossil fuel powered equipment both professionally and as a hobby and I wouldn't condemn an engine as needing a head gasket so quickly.