navvet

Ok don't laugh at this one!! I changed my oil @ 150 miles ago. It is a 1964 394 2 brrl. low compression engine. Engine has 81,000 documented miles. I have chaged oil three times in the past 2,000 miles. I checked my oil today and the level was fine BUT dark. I was shocked. I started the engine and ten minutes later checked it again. The color was more in line with oil after 1000 miles.. Is it normal for oil to be darker when it has sat for a couple of days.?
I am still concerned oil is as dirty as it is.
Do I have some contamination taking place!!! I had timing chain replaced
jsut prior to oil change could this be an issue!!
The engine is in such great shape and historic paperwork shows it was maintained like someones first child!!

navvet

I guess you are all still laughing!!!!. But I am concerned. Oil should not get that black after only 150 miles driven. When you sides stop hurting do any of you have a suggestion

hookem horns

Silly question, but did you change the filter also? Maybe some old oil that got mixed in when you drove it.

jaunty75

Change the oil again.

CQR

Most likely the oil you are using has detergents that are doing their job. You are probably cleaning the inside of your motor.

navvet

I did change filter. But I think to be on the safe side I will change oil and filter again.
I have 40W in it now. Quick observation: When I pull out dip stick and allow oil to drop off stick the oil easily rolls off! ( looks a bit thin for 40W) I noticed this when engine is cool.
Thanks for responding

hookem horns

If the oil looks "thin", does it smell like gas?

Tony72Cutlass'S'

I totally agree with that, The same thing happened with my cutlass earlier this year, engine running, oil is clean, engine off for a couple days, dipstick looked disgusting, i'm sure it's because the crap that the detergents are cleaning out are probably ferrous and they're getting attracted to your dipstick.

Anywho, long story short, 3 oil changes, 3 AC Filters and a bottle of Rislone zddp, my oil is clean as ever.

-Tony

navvet

The smell of gas is not overpowering ....I think the smell is typical for oil that has run thru the engine. But i am going to change it and the filter. I am going to examine the oil I am using. Maybe I need to up the quality of the oil. And I will be making sure I get a good product with ZDDP.
I will let you know how it does after a change .I am planning on a long trip soon after the oil change.

Indy_68_S

x 2 IMO...

I changed the oil & filter after my car sat for ~20 years. I dumped it again after only ~ 1 hour runtime / 25 miles. The 'new' oil looked almost as bad as the 'old' oil....

Allan R

Is the oil actually affecting your engine's performance or are you just concerned that it looks dirty? Oil does that. As others have said, could be the detergents. My Dad's 67 Cutlass (330) you could change the oil, drive it to work and back and the oil was as black as a witches heart in less than 20 miles. My 72 Cutlass oil was changed around 700 miles ago and is still clean and topped right up. I think it's just the way your engine does its business.

If you really want to dump oil and change filters a couple of times, IMO you've got more money to spend that could be buying fuel instead. I wouldn't worry about the color of the oil, especially since you've got the change cycle set at around 650 miles/change. Personally I think that's excessive. I'd be willing to bet you could change it 3 more times and you will have exactly the same results.

Mark71

This is ironic... A friend with an '09 Civic was complaining about the same thing today. I figured it was "normal". This is a newer car with around 30K on it.

fdwheelman

If its truly a concern - not that it will effect the engine, after all, today's oils are far superior to that of those used in the late 60's early 70's...

What I've done with every engine that ends up in my driveway with any kind of real mileage is buy the required amount of the cheapest oil that whatever parts store has. Match that with the cheapest filter. Sometimes you can find like a $12.99 or 9.99 deal. I also snag a can of motor flush.

Drain the old oil, replace with new minus a quart. Replace filter. Run the motor as instructed with the can of motor flush in it. After the instructed time, remove oil and flush mix, snag filter off. Wait a few minutes and then put your favorite oil and favorite filter in...

Should clear out or at the least, clear up a little.

rustyroger

40w oil sounds wrong to me, sure it's not 10w40?.
Oil darkens over time as contaminants from blow-by mix with it.
How long it takes is a good indication of how well the rings are sealing, lots of short trips will make the oil dirty up quicker. A little gas and water getting into the oil is normal for an engine of your vintage - every gallon of gas burned produces a gallon of water - a long trip at normal operating temperature is a good (and hopefully fun) way of boiling out these contaminants.
Roger.

navvet

I guess what concerned me is the fact the last three years this was NOT an issue.
I am very lucky the engine has low milage and want to make every effort to maintain it.
The oil I used was a detergent oil. Like I mentioned earlier I do have a long trip planned this weekend..... after a quick oil/filter change lets see how it looks after @ 300 mile road trip

Tedd Thompson

394's are notorious for blow buy, you could be getting recycled vapors.Have you seen abnormal amount of vapor coming out of the vent tube?...Just a thought.....Tedd

455man

You might check the air fuel mixture. Could be a dirty motor. I'm assuming you don't live on a dirt road.

getawaycar

You could buy an oil analysis kit from any of your local truck shops and have it checked out. Some of the Caterpillar shops even do it in house. If it is just a bunch of funk built up in the crank case add a quart of diesel fuel or ATF to the crankcase and idle the engine for ten or fifteen minutes to wash it all down to the pan. Let the system drain overnight and the engine will be a lot cleaner inside. The cleanest engines I have ever had apart have been the ones with fuel contamination. I use fuel to flush water contamination out of engine crankcases when I need to get all the muck out.

Chris

navvet

In regards to Ted's comment I have seen light smoke comming out of the PVC pipe when I disconnect fron the air filter housing.And the carb does need an overhaul. I have cleaned it and dumped a few bottles of seafoam in tank. Sometimes the engine sputters when I shut it off. That could be getting thru to the oil. Should I change oil (if it is blow by) to a differant viscosity or brand??

navvet

Update for everyone. I was lucky to have to take the car to work. Both POV's were in the shop. I drove @ 180 miles on a hot 95 deg. day. Highway and county road driving. (The car ran great no problems) When I arrived home I waited 20 minutes and the oil was clean. Last weekend I changed oil and filter . Looking back all of my trips were short after my last oil change..never more then 10-15 miles. Also a buddy who has more equipment then I do checked the carb and timing and she is way off. The carb can't be adjusted to correct specs and the air fuel mixture is not where it should be
I always knew the carb was a POS....is time for a rebuild.
Want to thank all for your ideas and opinions. Bottom line: I was using a detergent oil, I was driving very limited miles ,I have a bad carb set up,all contributing to the oil being suspicious in color. Bravo. YOU ALL HAD THE RIGHT ANSWER

Junkman

If you have blow by, then it is time to figure out what is causing it, and correct the problem. Blow by doesn't go away by changing oil viscosity, but by fixing the problem. Might not be what you want to hear, but it is better to fix it now, before it gets worse. Might be something like a broken piston ring that will score your cylinder walls, or it could be worn valve guides. You will only know once you investigate it. 70,000 miles is a lot on an engine that was built in the 1960's with a service life of no more than 100,000 miles if you were lucky.