Additives and fuel dilution

[driver123]

I recently tried a new fuel additive, I added the whole bottle (16 oz) , I noticed after about a half a tank, the car was running very rich, with the associated gray smoke as well, it has since stopped that. I ran the fuel tank to nearly empty, and since ive added about a half a tank of fuel, but when I checked my oil today it was nearly a half qt overfull and smelled of solvents. My question is this, can a fuel additive slip unburned past the rings and cause this kind of dilution?

 

[Donald]

In a properly running engine no. If you had bad rings then fuel with or without an additive might be able to get past. If it is or was running rich, I would think that might be an injector problem.

Does it still run rich after new gas? Get a used oil analysis to see the fuel dilution.

 

[dparm]

It might help if you told us the name of said additive.

 

[driver123]

Duralube severe fuel treatment

 

[driver123]

No, it's no longer running rich, at the time I wrote that off to overdosing on the additive,the directions said to add contents of bottle, but also that it treats up to 42 gals if I remember right, my tank holds 14. It's never had this issue before, any thoughts?

 

[MolaKule]

Your sensors in the feedback system probably indicated a lower octane situation due to the high ratio of additive-to-fuel, so the ECU may have upped the Fuel/air ratio by increasing the injector "ON-Time" and making the resulting mixture rich.

This thins the oil and reduces ring sealing and increases the fuel blowby during the intake stroke.

Anytime I do a fuel system, an induction or injector cleaning, I change the oil afterwards.