Did my first oil change on my X a couple weeks ago before my camping trip. The oil in the X was changed by the ford dealership (Tom Wood Ford IN) before I got the X. When I changed the oil it seemed to have that synthetic smell to it. I used rotella T because it is what we use in all our diesels and I just like it. it does seem like the 7.3 is a tiny bit louder then it was before which also makes me think the old oil may have been synthetic.

So anyone tell me how to tell if the old oil is synthetic or not? Do all ford dealerships use a standard diesel oil or is it up to their discretion?

The X was always serviced and taken care of at the dealership I bought it from. So if they used synthetic all its life I would probably like to continue it.

 

The dealer should have a record of what oil was used, but considering synthetic oil is more expensive, they typically don't use synthetic unless it's specifically requested, and paid for.

Different oils can change the sound of your engine. Not worse, just different. Perhaps your truck sounds better on Motorcraft oil which is what the dealer likely used.

 

I highly reccomend synthetic anyway, but you can switch to/from whenever.

When I went from the dealer oil at 3,000 miles to Amsoil 15-40... my cold starts got MUCH easier/quicker. Made a huge difference, and I'm convinced it ran quieter, too. I know it protects better as well.

 

Only problem I have ever noticed with switching from regular to synthetic is seals and gaskets start to leak. Switching the other way I am sure won't cause a problem but once one is used I like to stick with it.

I switched our 94.5 truck over to all synthetic in the rear end, tranny, and T-case, motor stays on rotella T. After a few months the transfer case puked all its fluid and locked up.

 

Unless the oil used was the wrong oil (Rating or viscosity) I don't believe for a second that it was caused by synthetic oil. Please, don't take it as an attack, it's not. But I have used synthetic oil in EVERY vehicle I have owned, including my 73 Mustang when I had it. Didn't leak a drop. It's curently in my GF's 84 Honda Magna w/ 40,000 miles on it, (sits 99% of the time), same thing, not a drop. (All other vehicles we currently have are 02-up)

 

I know its not an attack and some stuff is hard to believe especially on the internet. I take care of a small fleet of trucks and it just seems weird that the only one I switched over to synthetic was the one that had a problem and not long after the switch. I have read more then a few times about people making the switch on higher mile vehicles only to have leaks start. They don't leak when sitting, they leak when running and mostly around the seals. From what I read the molecular structure of synthetic allows it to "roll" past older worn in seals.

I personally saw it with the T-case in the 94. 400K+ miles on the truck, changed the T-case fluid only once before around 200K miles and it never leaked. Changed the fluid around 400K with synthetic and within a very very short time all the fluid leaked out the rear seal and locked up the case. Wasn't that big of a deal because it was only a $200 part but would hate to see that happen to the motor or rear end.

Maybe the leak started because of something else like dirt particles getting dislodged with the final fluid change, IDK and I can't say for sure. But when a person trys something new and it ruins a part they tend to be hesitant to try it again.

 

Synthetic resists temperature change.
Option 1) Take the truck for a drive just before the oil change. While draining the oil, touch the oil, it may be warm but it will not be hot.
Option 2) Get a sample from the engine during the oil change. Put it in a pan and heat the pan. The oil will not burn you if it is synthetic.

 

I have it all drained and in jugs. Will synthetic oil itself light on fire (burn)? I did drain it when the motor was warm and I remember the oil being warm because I was using the heat to check the level in my new oil drain pan. The motor was up to operating temp but not like fresh off the highway hot.

I have a small stainless dish that I could put some in and heat with a torch. I could heat the drained oil and some other regular oil for a certain amount of time and take a temp reading and see if there is a difference.

 

I'm no pro but synthetic oil gets hot, more than enough to burn you. Ask me how I know.

It also burns. You can burn synthetic oil the same as you burn regular oil. Don't ask because I can neither confirm nor deny...

Quite frankly the whole "heat it and try to burn yourself" test is kinda retartdeded. I'm not gonna shoot myself in the face to prove a gun is dangerous.