Engine/Transmission (1994 - 1998) Synthetic Oil in high mile truck?

[RCrowley]

My roommate bought his 94 CTD with 110,00 and started running 15w40 Amsoil Fully Synthetic in it. Over the past 70,000 miles it has gotten to the point where it burns a quart every 1,000 miles. How could this motor with only 180,000 on it be worn out? Could it be because he switched it to synthetic after it already had 110,000 miles on it with regular oil? Can the switch to synthetic cause problems with a high mile truck?



Thanks Ryan

 

[illflem]

Switching to syn on a high mileage truck can unplug leaks that were sludged shut before. Have no idea when the cutoff mileage is but even Amsoil salesmen say it's not a good idea in a high mileage truck.

 

[RacerBiggie]

I bought my '97 CTD two years ago with 141,000, switched over to the AMSOIL full synthetic, change it every 10K whether it needs it or not, and am at 188,000 with no drips, leaks or noticeable excess useage. Still getting 18-20 mpg. In fact, it's getting new injectors and new torque plate next week. I don't know why an AMSOIL dealer would NOT recommend it for high mileage applications. IMHO.

 

[Sled Puller]

I don't recommend it for the simple fact, the goody is all ready out of the engine. Amsoil cannot replace lost metal.



With the Cummins, however, 110,000 is no mileage at all.



Did you use the engine flush first? You should have.



Change the oil filter, and keep running it, what happened, is the Amsoil is cleaning all the sludge out of your piston rings, it will clean them up and start using less and less oil. Nothing wrong with the engine.



I just flushed and filled with the Diesel 5W-30, a 1986 Jeep 4 cyl, with 130,000 miles, that had not run for 2 years. The oil fill cap was missing, and we had to pressure wash the dern thing just to FIND the engine.



Valve cover leaked bad, had a hole in the gasket. Changed that, and the inside of the valve cover was covered with hardened sludge,varnish, as bad as you can imagine.



So far, no leaks, and it keeps running better and better, has to be cleaning the rings up. Be interesting to see what happens in the future to it.

 

[moparguy]

Ryan, in answer to your question as to how the engine could be worn out. One possibility is dusted rings. If the air filter isn't doing it's job, allowing dust/dirt into the engine it dosen't take a lot of miles to do the rings in. If that's the case, it dosen't matter what kind of oil he ran.



You might pull the air inlet hose to the turbo and see if it's dirty inside, are the turbo blades dirty, either or both is bad.



If he suspects the oil is the culprit, change to Delo or Rotello for a couple of changes, can't hurt based on what you reported.



Good luck, Ronnie

 

[Elite1]

Originally posted by RCrowley

My roommate bought his 94 CTD with 110,00 and started running 15w40 Amsoil Fully Synthetic in it. Over the past 70,000 miles it has gotten to the point where it burns a quart every 1,000 miles. How could this motor with only 180,000 on it be worn out? Could it be because he switched it to synthetic after it already had 110,000 miles on it with regular oil? Can the switch to synthetic cause problems with a high mile truck?



Thanks Ryan

Ryan, I put Delvac1, Mobil full synthetic, in my 96' CTD for the 1st time @ 155,000 miles... . no leaks and no oil usage, now have 169,000. Maybe they sold him snake oil! LOL... ... .

 

[tfrane]

My son bought a 92 with 192,000 miles on it. I switched it over to the same oil. I flushed it using a new filter. After about 10,000 miles, he added one quart so far.

Tim

 

[Deezul1]

I put Amsoil 15w 40 full synthetic in mine at 140. 000 and it now has 170,000 and doesnt use any oil between filter changes at 6000 miles.