AMSOIL SSO 0W-30, 4683 miles, 03 Celica 2ZZ-GE

[ltslimjim]

Originally Posted By: pcfxer
Gotcha'.

I usually say "yes" if I dump the oil and swap the filter out for a new one just to pre-empt OAI's recommendations. I've used the pump as well but the engine was not brought up to a high oil temperature and thus showed 2.6% on gas. I expected this because the gas was never burned off per se.

I've never thought that fuel would cause an oil to THICKEN over time and so I am concerned about the oxidation and oil thickening.

Can you verify whether the coolant system/cooling fans are operating as they should?


Well, the presence of fuel for a prolonged period is definitely causing an environment the oil must react to. Is this a result of nitration or oxidation from the fuel presence, causing to thicken some?

 

[xantonin]

Originally Posted By: pcfxer
Can you verify whether the coolant system/cooling fans are operating as they should?


Cooling system is rocking. Did a flush and it operates fantastically! I am running a 20/70 mix though. I was hoping for a 50/50 but stupid me I poured in the distilled water first instead of pre-mixing.... Still it's AZ, so I'm fine.
Originally Posted By: LeakySeals
Any use of fuel system cleaners? They can throw numbers off. Also I have seen leaky fuel injectors cause this. When the car is sitting for a while, fuel vapors from a leaky injector make their way out the intake manifold, through the throttle body plates, and into the clean air intake tube.


I use Amsoil P.i. before every oil change, so, before every oil sample. Maybe I should start adding it after? I'm just concerned over it's affect on the oil, and I figure if it's cleaning things out, I should change the oil after, so I have trouble using it on a fresh oil change.

I read somewhere I can disconnect my fuel rail, leave it plugged in though, and turn the key to allow the system to pressurize, and then watch for any leaks.

Any comments on doing that to test? I'll try it unless someone screams bloody murder to not do it.

 

[LeakySeals]

The most likely place combusted fuel can mix with the oil is the piston rings (AKA blow-by). Blow by is vented via the PCV system (PCV valve and crank case breather tube connected to your air intake). I was suggesting you verify both are clear of any buildup. It could be leaky injector vapor making its way back in through the PCV valve or crank breather, but the real issue in my opinion is a 0w synthetic is too thin for that year car with that mileage causing increased blow-by.

 

[LeakySeals]

Forgot to mention...Sounds like your using fuel injector cleaner every OCI? Today's name brand gas has cleaning additives mixed in, not the issue it used to be. An occasional use, maybe once a year is enough. If that injector cleaner does not have PEA additive its useless anyways. If you plan to perform a UOA use no additives including fuel...

 

[demarpaint]

At this point since we're all guessing at the cause for the fuel issues I'd opt for a cheaper off the shelf synthetic oil and change it out every 5000 miles. You can have a reliable shop test the injectors to see if they are leaking and go from there. As it stands now, extended drains are not in the cards for this vehicle. JMO

 

[AKhan87]

Old post I know but from the experience of getting my fuel injectors cleaned by RC Engineering the reports showed poor to good pattern after 165,000 miles on my car when I bought it used. After cleaning all were back to OE specs and my gas mileage significantly increased to oem estimated. No need for fuel injector cleaners if you keep your tank more then 1/4th full all the time and GT-S recommended octane rating is 91 or more, and I use 93 only since I got the car, it's a easy DIY removing/mailing/reinstalling fuel injectors on these cars. This is what I think was causing the fuel dilution.