Tale of two cobras...

Messages
3,635
Location
St. Charles County, Missouri
This from a link on Edmunds... http://forums.stangnet.com/showthread.php?s=&threadid=181031 Question-- What are we looking at here? Obviously the Mobil 1 valve cover is clean, clean, clean. The other one run on the dreaded Castrol dino for 30K and then switched to the hated Castrol phony syn for 10 is much dirtier. When I look down into the oil fill hole on my Elantra run with cheap crap Wal-Mart dino, I see oil about the same color as is on my dip stick. After a little over 1000 miles it's between maple syrup and honey colored. Some is visible on the cams and rockers inside the engine. Things don't look as dirty as the dirty 'Stang. But they certainly don't look as clean as the Mobil 1 'Stang. It just looks like the oil does on my dipstick down there. Question-- If all the parts inside the engine look totally clean with no oil clinging to anything, is that necessarily a good thing? If you pulled out a dip stick and it looked as clean as the top of the good Mobil 1 valve cover would that be normal? It seems like there's a big difference between having some dirty oil clinging to some surfaces and the kind of "gelling" visible in those Toyota posts. How much dirt is too much dirt? Is perfect "you could eat off this surface" like the Mobil 1 picture overkill?
 
Messages
1,933
Location
Oklahoma
His numbers don't jive quote: "RIGHT: An 1996 model with 30k miles on normal 10W-40, 10k miles on 5W-50 Castol Synthetic (I bought it at 30k)." Anyway he bought the car used. No telling how it was serviced and even though Mobil 1 certainly does keep a engine clean,,that cover was waaayyyy clean [Big Grin] I like the other guys observance of Quaker State. Not! He probably heard that sludge bit from a mechanic that replaced the water pump that went out and cracked the head because of the bad oil lead to muffler bearing failure as well [Razz] I have a friend that has over 230k on a 1985 Celebrity with that "junk" Quaker State oil. I bet it is not the cleanest motor in the world but is sure still runs well. I would say he has gotten his moneys worth
 

MolaKule

Staff member
Messages
21,591
Location
Iowegia - USA
When I pulled the valve covers on my '86 Burb (at 125,000 miles)to install the CC 260H Cam, the head banks looked similar to the Mobil 1 engine, except I had been running Amsoil 10W40 AMO then 10W30 ATM since run-in. The only difference was a slight condensate film which I attributed to the ester in the package. I would like to know the oil change intervals of the two. If 2-3k changes had been made with the dino Cobra, I would think it might be somewhat cleaner. What intervals had been done on the dino Cobra?
 
Messages
5,069
Location
Saratoga, NY
I had always wondered why I used Castrol (GTX & Syntec) and the oil seemed to stay very clean but if I switched to some other brand, it would turn dark brown almost immediately. Since then, I have assumed that Castrol's formulas stress lubricants over detergents and dispersants. This is fine for some cars ... but others seem prone to sludging. However, as was pointed out, there are too many variables in this situation to draw conclusive results ... and we still don't know how much cleanliness has to do with long engine life.
 

MolaKule

Staff member
Messages
21,591
Location
Iowegia - USA
Bror, If the sludge and microfine metallic particles are not cleaned off surfaces and dispersed, it gets into the piston ring pack. The rings will get carbonaceous material in the lands. Lubricant cannot get behind or beside the rings. Rings will not flex, they will not seat and the rings will stick and wear will increase. Blowby will increase as well. Cam wear will increase as well if the crud is not swept away from the surface. I for one want the crud to stay suspended and not have it deposited on any moving surface in my engine. TO me, clean engine internals are a sign that the detergent/dispersant package is working well enough to keep the crud in suspension and is not letting it deposit on rubbing surfaces.
 
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