I will be changing my oil next week, and think I will make the switch to 100% synthetic oil, most likely using the Amsoil 15/40. Will there be an initial issue when the change over occurs, such as mild contamination due to the dino oil still around somewhere? or is it so little it will not matter? If I do put in synthetic, and then decide to go back to Delo, will there be an issue there?
Thanks for the advice, Ken

 

You will/might notice more oil leaks with the synthetic , but this is the nature of the beast.

 

I switched to Amsoil about 11,000 miles ago, and I noticed mine uses a little more oil and I had a leak show up that wasn't there before, but it's well worth it for better engine protection and less oil changes. I'm going to switch to all synthetic when I get the money, but I'm too busy bombing now. Also, get the filter that Amsoil sells too, it's supposed to filter your oil really good.

 

I changed everything over to Amsoil. Sure glad I did . Better fuel economy truck just seems to glide down the road now. Have no oil leaks or consumtion. I use the Donaldson oil filter.

 

I use Mobil1. I seemed to go through a bit more oil for a bit after I switched over. Oil consuption is back down to about 2000-2500 miles per litre. My oil leaks seem no better or worse.

I had to replace the valve cover gasket in the wife's car after switching it to synthetic.

I remember reading that Amsoil recommends you run their cleaner in your crankcase for a while before you switch over. I'm thinking that this might be the reason for more oil leaks. But if it's what they recommend, I guess a person should do it.

 

I'm not running synthetic in my CTD yet, but based on past experience, you may find that the synthetic appears to get dirtier/darker quicker. This is because the synthetic will break down and suspend any sludge left behind by the dino oil.

 

This is the same reason synthetic may cause leaks on high mileage engines. The solvent effect of of the synthetic oil removes sludge that was blocking the leaks before.
I wouldn't even consider changing over to synthetic since my rigs have over 200k. A friend with 160k switched and wished he hadn't, leaks popped up all over.
It's definitely something worth considering if your engine has high miles.

 

I kind of thought it was from dyno oil rated for diesel use still had sulfer in it(not to be confused with fuel). The sulfer haveing caused seals to swell a bit from being in there a while on a high mileage engine. Then switch to synthetic with no sulfer, allowing the seals to shrink, combined with the extra lubricity, causing the leak to show. I had switched when I got my truck at 180,000. I started useing oil, and switched to part synthetic. I think it was either useing more at start-up or getting by the valve-seals, being thinner. Didn't use it long enuff to affect the seals. I also suspect guys with high mileage are actually burning a lot more of it at start-up than they think, but because they develope a wet spot, combined with a slightly lower oil level, think they are leaking more than they actually are. Just thinking out loud here.

 

IMO using a high end synthetic oil without a filter that allows extended drain intervals (like the new high end cyclonic ones at the very least) is a waste of the oils potential and its higher cost.
Its the dirt left in the oil that cannot be filtered by conventional standard filters that needs to be taken out, regardless if the oil is synthetic or dino. Syn oil will carry wear particles just as much as a dino oil if the filter system cannot take them out.
I wouild not run my oil longer if all I had was a standard filter system, no matter what oil I used in it. I think a by pass system is what is required to take advantage of a good synthetics long running potential.
Doing the math it was hard to make going to a great oil like Amsoil pay off unless you could keep it in the crankcase for at least 15k. I would not trust a cyclone filter(s) without oil analysis to back them up.

Anyway, good luck and watch out for letting the oil get dirty no matter what you do. (over 3-5 microns size)

Big Jimmy

 

With over 337,000 miles, I still don't have an oil leak with Amsoil. But I will say this, when the valve covers are removed, you can tell I'm not using dino oil. And to say synthetic oil breaks down, is a miss speak. It won't. It will get dirty, but a little cleaning with the dual by-pass and your good to go.

..PT..

 

I agree 100 percent the statement that synthetic won't break down. What I meant to say, though it could be interpreted differently,was that the synthetic would break the sludge down.

 

I think that's what was originally meant, that it would break down sludge build-up, but could be misunderstood the way it was written. I hate when I do that.

I switched my 96 over to Amsoil at 190K, and now, at 201K, it hasn't used any oil yet. The dipstick has become ornamental. I'm coming up on filter change time (12,500), so I will need to add a quart then....

And you can't get Amsoil filters for these trucks any more. Amsoil says the Donaldson is better and that what they offer now.

Chris

 

I switched to synthetic (Rotella) on my '96 at 355,000 miles. No oil related issues other than using some but it was doing that before switching over. Come to find out part of the problem was the turbo, putting a different one on has reduced oil usage. Have 393,400 miles now.

As far as using bypass I ran Amsoil in my 2001 HO and went 20,000 miles per change without bypass. I changed my oil filter twice between changes (which is 3 times per change) and oil analysis always came back great. I sampled every 10k miles.

Vaughn

 

That is interesting.
I wonder how that might affect long term longevity.

A standard filter only gets down to 25-30 microns so is the Amsoil reducing wear so much that with even long change intervals and standard filters thats enough to do the job or is the Cummins such a great engine that with a ton of wear particles in the oil it still wears well?

How hard do you work that motor anyway?


Jimmy

 

What the Amsoil does, is hold particles in suspension. Like soot. I guess I'm saying it does not let them adhere to the engine parts. What Vaughn is doing I would not do. The FleetGuard filter is one of the best, but if a problem arise's form the use of them, Amsoil does not warranty the product. Now what does that really mean? Who knows. But I do know Amsoil says to use their filter, of course, and follow their instructions, and they assume responsibility for the results. But if it works for Vaughn, it works. You cannot argue with that.

I just went ahead and installed the dual bypass about 6 years ago and I change the full flow filter every 10-15,000 miles, and the bypass filter once a year. I change the oil once a year, though Oil Anaylsis say's there is no need too.

This kinda of topic could go on forever, but the bottom line is, nobody knows everything about how these engines react to different oils or additives. We all try different things because we are what we are. Tinker'ers. I love it myself. We always learn new things to try.

Keep on keeping on.

..Preston..