Shorter OCI as engine gets older?

[KitaCam]

I got the Kitacamry @ 97k miles with minor varnishing with 5-10k conventional oil OCIs...I switched to syn @ 100k and after 26k miles/four 5-7k-mile OCIs I'll pull the valve cover again to see if there's any change/improvement...

I have noticed that the engine is quieter when oil level is full, so if the engine looks good, after this OCI I'll be topping off/refreshing the sump when down a 1/2 quart and I'll extend the OCI from 5-7k to 8-10k miles with no worry.

 

[Bluestream]

Originally Posted By: dblshock
Originally Posted By: Bluestream
Originally Posted By: dblshock
clean'r up, start TCW-3 oil in the fuel 640/1.


Are you kidding??

Not at all..run it in all my engines...numerous threads on the subject.


Any Professional papers done on this like the SAE? Or backyard hacks thinking their gas is "dry"

 

[deven]

Another reason to do shorter OCI's on an older engine is due to the fact that other things can go wrong and can really warp an oil. If your water pump were to fail, you'd rather have fresh oil in there rather than an oil with 8,000 miles on it.

 

[Merkava_4]

Originally Posted By: The Critic
The car calls for 10k intervals on 0w-20 synthetic.


I'd divide that number in half for the OCI on synthetic.

 

[circuitsmith]

Check the air filter. Make sure it's intact and the gasket is sealing good.
I saw a case where the oil got blackened because the mangled air filter was letting dirt into the engine.