Rotella T4 oil, dirty oil
 

Starting a new thread about what I posted in the thread below, so as not to hijack the other thread.


https://www.fordbarn.com/forum/showthread.php?t=273067


Post 23 -
It "has always bothered me that my oil is so black at 500 miles. Even with rebuilt motor, Berts carb, and decent plug reads".

"Have considered changing from Shell T4 to something different, have heard claims that Rotella t4 looks dirty sooner than other oils."


Can no longer find the info about T4 running dirty/black. Not sure; if it is because it is a diesel oil, if it requires more frequent changes that other brand/type oils, etc. Would appreciate info/comments.


Am I overly concerned about something that is typical for all oils in a Model A Engine without an oil filter?


If because of dirty oil at 500 miles you have switched from T4 to another oil please comment including type of oil. Or if you have added an oil filter due to dirty oil at 500 miles please comment.


And yes I know some are probably thinking - not another discussion about oil. So please do not let this morph into other oil subjects/areas. I am not looking for info on what is good oil, best oil, additives, etc..

Re: Rotella T4 oil, dirty oil
 

My gut tells me that the dirty black oil isn't specific to Rotella.



I would suggest changing the oil on your modern car at 500 miles and you'll probably find that the oil is also black and seemingly dirty. Oil gets dark very quickly after an oil change but that doesn't mean it's not doing its job.


Of course oil will get more dirty more quickly in an A given the lack of air and oil filters on most of them which is why the 500 mile change interval (though I think is too short with modern oils). With a new engine like you have I wouldn't worry much. Do you run an air filter? I can't remember.

Re: Rotella T4 oil, dirty oil
 

The above post is really accurate. Filters make a BIG difference. Especially an air filter.

Concerning T4, or any Diesel specific oil, they are intended to "pick up" soot, which is much more of a problem in diesel engines. So yes, it may appear darker, sooner. I wouldn't sweat it any, we've been running diesel oil in ours for generations.

Side thought, I'd rather drain dark oil, than have all that stuff stuck to the engine internals.

Disclaimer: this is an opinion, not scientific fact, but based on experience.

Sent from my E6810 using Tapatalk

Re: Rotella T4 oil, dirty oil
 

The oil is doing what it is designed to do by holding particulate in suspension so that it doesn't form sludge in the engine. Good filtration helps to clean a lot of this stuff out but it depends on the type of filtration the engine is equipped with.

An engine that has run a while with low or no detergent levels in the oil will get dark quickly from all the sludge build up already in the engine. Engines with carburetors don't run as efficiently as modern fuel injected engines so it's not uncommon for the lubricant to darken with the extra contaminants that come from inefficient combustion and or worn compression rings.

Lubricants designed for diesel burning engines generally don't have the same additive package as the lubricants designed for gasoline burners. The oil for diesels have a lot more detergent additives than gasoline burning vehicles.

Re: Rotella T4 oil, dirty oil
 

Another reason for my concern - Last oil change I went 750 miles before changing, and was shocked to see black sticky/a little gooey stuff in the drain plug cavity,. Beginnings of sludge? Don't know. 1st time I have seen it. Do not know if the previous oil change I installed a magnetic oil plug had anything to do with this, but I did not see anything metallic in the plug or in the drain oil.


Tried a High Boy/K & N air filter this year for awhile, took it off while dealing with other issues. Trying to get the truck running the way I want it to, then base line MPGs and oil condition/changes. Then add air filter, baseline it again, then perhaps add an oil filter and baseline again.


I gave up for awhile, just wanted to enjoy driving the truck for awhile, but plan on getting back to this once I get the brakes sorted out next spring.


As you might be able to tell, am retired with too much time on my hands, but am definitely not a mechanic. Nothing is obvious for me when dealing with something the 1st time.

Re: Rotella T4 oil, dirty oil
 

I guess what started a lot of my concern is seeing info/posts that Ars without filters posting they get 800-1000 miles before the oil turning real black (what I consider an india ink black).

As I just posted above to Ryan, a second concern is
"Another reason for my concern - Last oil change I went 750 miles before changing, and was shocked to see black sticky/a little gooey stuff in the drain plug cavity,. Beginnings of sludge? Don't know. I did not see any sludgy/thick stuff in the drain oil. 1st time I have seen it. Do not know if the previous oil change I installed a magnetic oil plug had anything to do with this, but I did not see anything metallic in the plug or in the drain oil."
So should I be concerned about what I found in the drain Plug - or is this typical, not to worry about?

Re: Rotella T4 oil, dirty oil
 

I run Motorcraft 10W30 and change once a year in late-fall before the winter storage, and it is never really very dirty at all.

In fact I probably should take THAT oil and dump it in my everyday car. That wouldn't hurt a darn thing:o

Re: Rotella T4 oil, dirty oil
 

I saved a couple of my 100 mile changes from my new engine and used it in my new car :D

Re: Rotella T4 oil, dirty oil
 

I use Rotella 15-40 and change it at about 500 miles. I have a K&N air filter but no oil filter. At 500 miles my oil is a little dark but no way black. If I put a drop on my finger I can still see my finger though the oil.

Re: Rotella T4 oil, dirty oil
 

Do you run any filters?

Re: Rotella T4 oil, dirty oil
 

When I check mine at 100 miles or so, not much discoloration, looks very fresh, but at 500 is very black.


How many miles on your new engine? Mine was rebuilt last winter, but put on over 3000 miles this year. I also changed very frequently the 1st 1000 miles.

Re: Rotella T4 oil, dirty oil
 

Do you run an carb balancing modification since you are running an air filter?

Re: Rotella T4 oil, dirty oil
 

I've got about 1300 miles on it this season. Would have driven more but working on repairing some rotten wood I found. Changed it every 100 miles until it started coming out almost as clean as when it went in. Probably have about 400 miles on this oil change and it still looks new on the dipstick. I'm sure it would look dark if I drain it though.

Re: Rotella T4 oil, dirty oil
 

If you're wondering about "dirty" your oil is, just send off a sample for a real analysis. Without seeing/feeling/smelling your oil, no one on this site can give an informed opinion, anyway! Look online for an analysis company, or ask a heavy equipment or truck dealer.

Re: Rotella T4 oil, dirty oil
 

Thanks, that's a great idea.


I vaguely remember seeing it mentioned in the distant past, but had forgotten.


Will have to search the Barn and see what comes up. Then go online/google. Issue is I searched on oil subjects, but there is so much of it seems like it would be a weeks reading to get through it all.


Next year at oil change hopefully I will remember to save some of the used oil and send it in somewhere.

Re: Rotella T4 oil, dirty oil
 

No and I don't think it is necessary at least with a K&N. My plugs look good never fowl and I have never cleaned them.

Re: Rotella T4 oil, dirty oil
 

If you have a Caterpillar dealer in your proximity, might be a good place to start.

Sent from my E6810 using Tapatalk

Re: Rotella T4 oil, dirty oil
 

I have explained here before that when I am touring outback with a camper trailer in tow, I judge when to change the oil by watching my instruments.
The engine has oil and air filters, 5.5:1 head, a downdraught Stromberg carburettor from a 1950's Holden and a very mild cam. The middle main bearing is pressure fed at 25 psi. With new oil and travelling at 50 mph and 180 F temp, the oil pressure is 25 psi. Eventually, at the same speed and temperature, the oil pressure starts to drop. The oil has "lost its guts". When the pressure is down to 23 psi, I change the oil and that is quite reliably at 3,500 mile intervals. I use the cheapest 20W50 oil available and ignore the colour of it.
Just my experience. BTW, I have done about 40,000 miles on that engine like that so far.

Re: Rotella T4 oil, dirty oil
 

Your oil is not getting dark because it is the wrong oil. The air and oil filters also have little to do with it. It gets dark because of the incomplete and inefficient combustion of the Model A engine. Unburned fuel and water are the biggest culprits. Your modern car stays cleaner-looking longer because it is much more efficient. Raise the temperature of your engine with a thermostat, use a higher compression head, run leaner and advance your timing as much as you can without preignition will all help you burn your fuel cleaner, however, a Model A engine will never be as efficient and clean as a modern engine. Don,t worry about it, It's normal. Just enjoy your car, and if you don't use an oil filter, Keep changing your oil at 500 miles.

Re: Rotella T4 oil, dirty oil
 

Best explanation yet!