Switched to synthetic

[USAFdieselman]

I was due for an oil change and couldn't find any 5W-40 Rotella, so I bought the Synthetic 5W-40 for the truck. I normally run 15W40 without any issues but wanted to try something different. Could I have potentially screwed something up? I have been smelling burnt oil for the last few days around the engine compartment but no leaks that I see. Should I just drain it out and go back to 15W40 or what?

[RedneckGirl]

5W in a 7.3?

I'm no oil expert-but I'd go back to running what the book at least suggests-15W-40 in my manual.

I don't think the synthetic part of things is going to cause you trouble-its just that the weight of the oil isn't heavy enough. The PSD uses oil pressure to run multiple engine components and I know that frothing and breakdown of oil could cause other issues.

[jackpine savages]

I don't think you could have screwed anything up, but one thing I know you should do is change the filter again. Soon. After running dino. oil you get sludge deposits here and there that will be worked loose by the synthetic. Particularly 5w/40. Hang a fresh filter after 500 miles or so.

I'd say you would also want to be careful with the service duty with that weight of oil in there-no heavy pulling. Did you put in the Rotella Synth.?

[RedneckGirl]

Originally Posted by jackpine savages

I don't think you could have screwed anything up, but one thing I know you should do is change the filter again. Soon. After running dino. oil you get sludge deposits here and there that will be worked loose by the synthetic. Particularly 5w/40. Hang a fresh filter after 500 miles or so.

I totally agree with the changing of the filter. When switching to synthetics it's best to change filters due to the sludge that will break loose. My ex is a dealer for Amsoil and they suggest multiple filter changes when first changing to their products.

[USAFdieselman]

Damn...well looks like I am going to go back to 15W40 regular dino. I don't like the smell of oil every time I stop, it does seem to smoke a bit more. But I think that is just because the lighter oil maybe getting by a seal or something.

[ncbowhunter]

i just changed my oil today and only had 13 qts of the rotella 15w 40 so i put in two qts of mobil syn. 5w 30. i did not want to run back out to the store. i dont think it will hurt anything.

[RC51]

A lot of guys and gals run 5w40 in the winter. I would not mix dino and syn or any oil in diff weights.

[vitalidle]

I have been running 5w-40 the last two oil changes. I need to do an oil analysis to make sure Im okay. I know alot of people say its a bad thing, but its made a hell of a difference on my starting in the winter.

[Logan]

You might have spilled some and it is just burning off.

[Lord Tauk]

I've been running 5W-40 for months.