Mmo

[OldNuc]

If you want to see what pistons look like that have completely filed rings on dino oil with regular oil/filter changes and about 170,000 miles go look at ehunters rebuild thread. The dino oil can not withstand the hypereutectic operating temperature and bakes to thick hard varnish.
http://www.saturnfans.com/forums/sho...d.php?t=170045

[cheapybob]

Originally Posted by OldNuc

If you want to see what pistons look like that have completely filed rings on dino oil with regular oil/filter changes and about 170,000 miles go look at ehunters rebuild thread. The dino oil can not withstand the hypereutectic operating temperature and bakes to thick hard varnish.
http://www.saturnfans.com/forums/sho...d.php?t=170045

If you look at post #145 in that thread the valvetrain is immaculately clean compared to what my previous DOHC looked like, and yet his piston rings were still caked and baked in sludge. I can't even imagine how bad mine must have been.

Maybe I'll put synthetic and a cleaner additive (seafoam or mmo or rislone) in the SOHC I got. Its not using much oil, I don't think, and I have plenty of synthetic sitting around to last a few years

The other DOHC I still have is anther story. It uses lots of oil. I did put Seafoam in it recently, but based on this I don't give it much hope of fixing it. Maybe in the spring I'll give the soaks a try on it and try to see if it helps any. It would cost a fortune to feed it synthetic, so that's out unless consumption drops.

Thanks for the info....

[PlasticCarsRock]

Originally Posted by cheapybob

If you look at post #145 in that thread the valvetrain is immaculately clean compared to what my previous DOHC looked like, and yet his piston rings were still caked and baked in sludge. I can't even imagine how bad mine must have been.

Well, the valve-train (and head in general) is no indication of anything: look at where the heat meets the block under where the TCC would go--it's easy to see that the head does not even remotely match the condition of the block, indicating that it has been recently replaced. Post #147 indicates that the head was replaced just one month before the tear-down (the head gasket was replaced, at least, so it's almost certain the head was being replaced, or at the very least, cleaned well).

Originally Posted by cheapybob

Maybe I'll put synthetic and a cleaner additive (seafoam or mmo or rislone) in the SOHC I got. Its not using much oil, I don't think, and I have plenty of synthetic sitting around to last a few years

If you have it, you might as well use it--even if it doesn't ultimately prevent the classic oil burning problem, it will certainly extend the time that it takes to develop.

Originally Posted by cheapybob

The other DOHC I still have is anther story. It uses lots of oil. I did put Seafoam in it recently, but based on this I don't give it much hope of fixing it. Maybe in the spring I'll give the soaks a try on it and try to see if it helps any. It would cost a fortune to feed it synthetic, so that's out unless consumption drops.

You might as well give it a few soaks--$3 for a quart of MMO (or a bit more, for Seafoam) is way cheaper than a rebuild. It's not a guaranteed or 100% fix, by any means, but based on others' experiences, there's at least a decent chance that it will improve things a bit, and even if it only saves you 2 quarts of oil in the rest of the time you have the car, it will have paid for itself.

[cheapybob]

Originally Posted by PlasticCarsRock

Well, the valve-train (and head in general) is no indication of anything: look at where the heat meets the block under where the TCC would go--it's easy to see that the head does not even remotely match the condition of the block, indicating that it has been recently replaced. Post #147 indicates that the head was replaced just one month before the tear-down (the head gasket was replaced, at least, so it's almost certain the head was being replaced, or at the very least, cleaned well).

Sorry, I hadn't noticed that part, and should have realized it looked too clean compared to the bottom. The bottom part looks more like the color my valvetrain was.

[DIYguy]

badbobby said- By deisel oil do you mean deisel fuel? in the oil pan??? Also why not piston soak? Yes I have heard a lot of good comments on seafoam. And yes walmart rocks on their prices on most oil products including synthetic oils.

No, absolutely not. I mean that you should use diesel oil such as Rotella or Delvac or Delo for your next oil change. It is typically 15W40 and I have seen no issues using it. I alternate between that and 5W30 full synthetic on oil changes and it seems to keep everything very clean.

As for Seafoam, I have posted their MSDS a couple of times. Basically if you buy about a quart of naptha, a quart of isopropyl alcohol (painting grade), and a quart of 3-in-1 oil, you can mix up a batch of your own (the wintergreen scent is optional). Or, just buy Seafoam....

PlasticCarsRock said- No... he/she means diesel oil... oil designed and marketed to be used in diesel engines. While the detergents in diesel oils are not optimal for use in gas engines, they do tend to clean a bit better. Regular synthetic oil is still a far better choice, though.

He, actually. That's my wife on the hood of the car in the avatar (at a very young age obviously), and my sister-in-law who is an artist created the avatar. .

I disagree on the synthetic as a better choice as a hard rule. After I overhauled my engine I ran nothing but 5W RP and other synthetics for a long time so I wouldn't compromise my fresh overhaul. The problem is that any tiny little leak will be magnified using it. After fixing them all, I still noticed a long term trend toward using oil again.

I have diesel oil around for other "vehicles" so I tried it on an oil change and it came out a couple of thousand miles later absolutely filthy. But the minor oil usage basically stopped.

So now I alternate between them and it seems to work quite nicely. Even the synthetic comes out dark now. So I can only conclude that the combination is working to keep everything clean (plus I opened up the cam cover recently and it looks as clean as when I buttoned it up during the overhaul).

Oh, and I have noticed little or no meaningful difference in gas mileage when switching back and forth between 5W30 synthetic and 15W40 Delo. There might be some difference, but it's very small and lost in traffic and weather patterns, so I can't put a number on it. I use a tank a week and keep very careful records.

BTW I do use synthetic the BMW and my wife's truck (and even in the old Honda), but they don't have the oil ring problem that the SC2 has/had.