Cleaning Up HDEO vs PCMO

[Jim Allen]

Coincidentally, the oil changes for my '86 Ford 6.9L diesel pickup and our '00 Honda Accord V6 came near to each other. I dump my used oil into five gallon containers for recycling and then clean up the drain pan with a little brakecleen and rags. The HDEO (in this case Shell Rotella 10W-30) is always a bear to get cleaned out of the pan, even with the help of the brake cleaner. The solvent doesn't "cut" the oil very well or very quickly, and the oil will really stick to the pan when I upend it for draining.

On the other hand, the 5w30 Castrol GTX/Syntec home blend cleans out rather easily with the brake clean and doesn't stick as well when the pan is upended.

Both oils have about the same mileage, 6-7000 miles, and the ambient temp was roughly the same. If anything, it was a little colder for the Castrol.

Anyway, I'm wasting my time wondering if the differences say more about the difference between a HDEO and a PCMO or the differences between Shell Rotella and Castrol. I've had good luck/OAs long term with both oils in their respective applications.

 

[LargeCarManX2]

I believe the experts called it "Tactivity" More than likely, the HDEO has more tacky additives than the PCMO...

 

[Towel_Rail]

Any particular need to have the pan clean afterwards?

 

[Dr_No]

I think the word is tackifiers.

 

[bruce381]

soot will make the oil stickier and thicker in use
the vis diference maybe what you are seeing.

PCMO's do not have 'tackifiers" they are used in gear, chain, bearing and industrial non drip oils.
bruce

 

[njohnson]

PCMO's may not contain "tackifiers", but different oils have different characteristics. Could the difference that Jim Allen sees between the two oils be due to the type of base stocks that Shell uses? I am not an oil expert by any means, but I'm having a similiar experience with the Shell Rotella I'm using.

Our Isuzu Trooper has some kind of gear set that you can see through the oil fill cap. I like to peer down through the oil cap whenever I add oil to the SUV to check how the engine internals are holding up.

For almost all of its life, the Trooper has had Amsoil in the engine. Well, this fall, due to a tight budget, I used Shell Rotella, intead of Amsoil. With Amsoil, I noticed that if the Trooper sat longer than one day without being run, the gear set would be dry as if the oil was draining off the gear teath. With Shell Rotella, when I peer down the oil fill port, the gear teath are still visibly coated oil, even if the Trooper hasn't been run for a couple days.

I know, I know, it is not very scientific, but that is what I have noticed.

 

[njohnson]

PCMO's may not contain "tackifiers", but different oils have different characteristics. Could the difference that Jim Allen sees between the two oils be due to the type of base stocks that Shell uses? I am not an oil expert by any means, but I'm having a similiar experience with the Shell Rotella I'm using.

Our Isuzu Trooper has some kind of gear set that you can see through the oil fill cap. I like to peer down through the oil cap whenever I add oil to the SUV to check how the engine internals are holding up.

For almost all of its life, the Trooper has had Amsoil in the engine. Well, this fall, due to a tight budget, I used Shell Rotella, intead of Amsoil. With Amsoil, I noticed that if the Trooper sat longer than one day without being run, the gear set would be dry as if the oil was draining off the gear teath. With Shell Rotella, when I peer down the oil fill port, the gear teath are still visibly coated oil, even if the Trooper hasn't been run for a couple days.

I know, I know, it is not very scientific, but that is what I have noticed.

 

[bruce381]

all oils will drian off over time perhaps some are better than other though vis and color will affect what you see.
bruce

 

[Jim Allen]

Well, some thoughts to consider. Thanks! The color isn't a factor, Bruce. You can see the HDEO oil really stickin' there and pretty much ignoring the brakeleen. Not so for the PCMO. I hadn't considered the soot aspect.

Towel Rail: I like to have clean pans for several reasons. One is that my wife is very sensitive to "car" odors. Motor oil isn't too bad, but gear oil and ATF... well let's just say that those lubricants don't stop that squeaky wheel from squeakin' if she catches a whiff of a nasty pan in the garage. The second is that my oil goes to a guy that burns it in a heating unit and the cleaner I get it to him, the better and easier it is for him. Mostly that means keeping water out.

 

[Towel_Rail]

That's rough, having to keep a clean-smelling garage... is the missus allergic to that stuff, or is it just kind of a "keeping the peace" deal?

 

[Jim Allen]

Towel Rail: Both. Gas smells will make her instantly ill for real. The other odors not so much, but she's gunshy and after a really bad experience for her, she overreacts to strong car odors. It's not too much extra work to keep her happy... but I go through lots of Ozium! Next year I'll have a separate shop not attached to the house and I'll likely joyfully let my drain pans get really nasty for a while! Unless I've been so conditioned over the past two decades that I can't break the "Mr. Clean" habit.

 

[mzugg]

I've noticed the same thing with Delo 15w40 vs. anything else (PCMO). I don't have to get the pan squeaky clean, but I notice that even with an extended drip out period, it's still coated with that Delo. I suspect that coating is a good thing if you're an engine.

You're not crazy - at least not crazier than I.