My 7.3 idi turbo has 182k on it. I use regular non synthetic rottella t 15w40. Would it be wise or a poor decision for the engine to switch to the rottella t 15w40 synthetic?

 

Is it leaking/weeping oil?

If it is, definitely don't switch until you've replaced the leaking seals. Synthetic makes failing seals worse.

If everything is in good shape, go for it. Worse case, you'll develop leaks and want to change back(or replace the seals).

The only other thing to consider is this is a very 'dirty' engine, as far as blowby and stuff getting into the oil goes.
I feel it safer to just use conventional and change it out every 2500 miles than to go for synthetic and go far longer... Unless you go to the trouble of installing a good bypass filter, then it might be fine.

 

the front crank seal is leaking. It doesn't drip on the ground but its seeped enough to become real thick on the from off the pan. And also the pan gasket itself doesn't leak but around the bolts is a little bit of caked oil that's dried up with dirt but I usually go 3000 ish on an oil change so I do about 3 oil changes a year. Which I'm ok with. Just thought synthetic to clean up inside the engine. As for blown if I take oil cap off while running almost no steam at all. Even if I give it throttle. Like it's a struggle to see it. Vs YouTube videos I see where people do this and smoke is coming out the cap like crazy. My main goal is to just keep a healthy engine.

 

Yeah, it'll leak worse with synthetic.

If you change conventional on a regular basis, it'll clean up as well.
I pulled the valve cover off my '93 which was obviously kept up on oil changes(and I've been running conventional myself)... and the valves were spotless. Oily, but no deposits/build up.

...Of course, if you end up with worn valve guides, you'll end up with crud up there no matter what you do, from the hot exhaust gasses burning the oil.


You have a CDR. The CDR is at the back of the intake manifold, and sucks all the blowby into the intake manifold.
Pull the air cleaner off and watch it idle, look down the intake hole.
You should see a nice thick stream of blowby coming from the hole at the back of the manifold forward and getting pulled into the cylinders.

...Which is typical; even a newly rebuilt IDI will do it. It's because of the massive ring gaps in the engine design.

 

how much blowby is acceptable? Also that cdr valve is real bad in my engine. I have a new one coming in the mail Friday. It's super bad.

 

There's something in the ford service manual about blocking off the CDR port with cardboar, putting a calibrated restriction(orifice) into the oil cap hole and measuring the pressure built up behind it.

The real answer is... don't worry about it as long as your oil consumption isn't bad. All of those gasses get re-burned anyway; the only issue is how much oil gets used up.

 

well fortunately the engine doesn't even use any oil between oil changes. I always check it before I drain it and it's always right on the money