Oil change

[Rodney Bullock]

I changed the oil in the 1940 plymouth today and noticed the oil at the end of the drain was very watery. I checked the radiator and it was full, after looking at the oil in the drain pan. It looked like foam was on top. The oil was thick while it was coming out in the beginning. Only at the end was it milky I wonder what made this happen? I replaced it with Rottela-t should I use something to make sure I have more lube there any opinions?

[Normspeed]

Rodney, have you spray washed your motor recently? Maybe some water got in past the oil filler. Also how long since the last change?

[Norm's Coupe]

It could be caused by condensation too. If the car sat for a long period, then only run for short times without fully warming up, that will cause the moisture in the oil too. Changing the oil will take care of the problem. If you start the car up during long storage times you should always allow it to get up to full operating temperature before shutting the engine off. If you do that, it will not allow the condensation to form in the engine.

[Merle Coggins]

Wait a minute guys. Water is heavier than oil. If it was water is should have been on the bottom and drained first.

I'm not sure what substance it may have been, but I'm quite sure it wasn't water/moisuture if it was the last thing to drain. Did you have the engine running just before draining the oil? It may have just been airated oil laying in top.

Merle

[Normspeed]

Merle's right, water should be the first thing to come out of the pan. But the foam coming out doesn't sound good.

[Norm's Coupe]

Merle's right, water should be the first thing to come out of the pan. But the foam coming out doesn't sound good.

Norm, up here in the northern cold climates you'll see that happening every now and then in cars. As mentioned, in most cases it's just condensation that has gotten inside the engine from temperature changes. Around here you'll see smoke coming out of just about all the cars in the winter. It's normal though and just the condensation burning off. Once the car is thoroughly warmed up, the smoke stops. It's just steam. If you don't let that steam burn off by thoroughly warming the engines up, it will settle into the oil pan and turn the oil milky looking.

To give you an example. I start and run my P15 all year round every few weeks during the winter. During the winter when I start it up you'll see smoke (steam) coming out the tail pipe. It's just water, not running rich or oil burning. Look at the tail pipe and you'll see the water dripping out of it. After the car has run 10 to 20 minutes (depending on outside temperature), the steam stops and so does the water dripping out the tail pipe. Happens in all cars up here, new and old. The only reason the oil in my P15 doesn't get milky colored is because I always let the car run long enough to burn off the condensation. We don't have this problem in the warm months.

[Merle Coggins]

That is all correct Norm. What we're saying is that any water would be a the bottom of the pan and would drain first, not near the end. Or all of the oil would be milky, not just the last bit. If only a portion of the oil got mixed with water and became milky, it would still settle to the bottom.

Rodney stated that it looked foamy. This would indicate that the oil got airated, either from windage inside the crankcase, or his lube system is sucking air before the oil pump (which isn't very likely or he'd have other problems). If it is a detergent type oil it may be getting foamed from the windage / splash in the crankcase.

Rodney, now that you've got the Rotella in there, check your oil level just after shutting the engine off. If there are bubbles or foam on the dipstick, you may need to investigate further. Most modern oils have antifoaming agents added to prevent this.

Merle

[Rodney Bullock]

Thanks for the timely responses, I did start the car and let it run for a while before I took the oil plug out. I must confess I don't let the car warm up until the steam stops coming out of the tail pipe. I start the car in the winter however I don't let it run long because it's in the garage, It will kill me! Just joking. I used HD 30 weight oil last time I changed it, Thinking back I dd wash the motor last year and the main place I concentrated the gunk and water stream was at that spout coming out from the bottom that conects to the oil pan. The oil level must have been low because it did not fill the drain pan like the other cars did when I changed the oil in them( I changed the oil in all three antiques ) so It might have been very low. When I drove the car a couple of miles and then pulled over and rechecked the oil there was no foam on the stick, I looked for that, I might be ok, one thing is for certain with this car I have never heard the valves tap even with the condensation it runs like no other 6cly I have, I hope it stays that way. thanks all, PS. Is Rottella-t as good as they say?

[grey beard]

Fifteen or twenty minutes of idle tuime will of course get the thermostat off its seat and the temp gauge up to normal, but if you cralwled underneath and felt the oil pan or lower block, you would discover that it is still pretty chilly. It takes at least thirty minutes of idle time or 15/20 minutes of road time to get a flathead engine really to operating temperature. The places that matter in this regard are those places where condensation collects - valve chambers and oil pan. If the oil does not get warm enough for the condensation moisture to evaporate, it will continue to build up in the engine and eventually begin to create sludge. Having said all that, I try to never start an old engine unless it will run for at least thirty minutes or thirty miles. Then I know everything is hot enough expel the moisture.

If you start your pride up cold and let it run fifteen or twenty minutes and then drain the oil, the stuff that drains out will still be room temperature. There is a tremendous difference between temp gauge/water jacket temperature and oil pan temperature.

Looking at the issue from the other side, truck and tractor engines that run for extended intervals and work against the governor for hours on end, seldom if ever show any sludge or condensation damage. I have seen Cummins engines with over one million miles taken apart for the first time and the valve springs and head casting marks still looked like new. A man who goes to our church is an owner operator with a 425 Cat engine in his turck, and he now has 1,250,000 miles and still counting, and the pan has never been down or a head off - just injectors and turbine repair to date. Does all his own service, too. Amazing, I think, and I believe our flattie engines could approach that sort of service, given similar operating conditions.

I run a 180 thermostat, a PCV system and a paper air filter. All this helps, but nothing can make an old flathead heavy casting block warm up any faster than normal operating conditions, unless you live at the foot of a huge mountain and climb to the top each startup. JMHO:p