96 Tacoma skipping

Well there is straight weight oil and multi weight. The multi weight has viscosity modifiers added that resist thinning when heated.

Straight 30 weight heated to 212 will still be way thinner than room temp straight 5 weight.

A 5w-30 will be thin enough and flow well at freezing temperatures. Behaving like a straight 5 weight oil when straight 5 weight is cold. (Same viscosity). When it's heated to engine temps it will resist thinning, and have the same flow characteristics as hot straight 30 weight.

 

Holy fuck keep the oil bs to a different thread so the op can actually get decent feedback.

 

Sorry, my bad ...

 

were discussing the differences in the dynamics of motor oil so we can fully understand weather or not the oil issue the OPs friend was mentioning is a legitimate issue that could cause the problem the OP is having. this oil discussion couldn't be more relevant...

from everything that has been discussed, the oil cannot be the issue. switching to a different oil shouldn't do anything.

it's more likely that the motor is building up too much pressure inside and has no relief, thusly causing issues like air getting passed the rings and causing misfires. this is why I mentioned to remove the PCV valve, or just change it along with the grommet since theyre not that expensive, and see what happens.

Ultimately I'm thinking that the PCV valve is holding air back and building up too much pressure. which is why the OP didn't have an issue after changing the oil, all the pressure was relieved when he removed the drain plug and the oil filler cap.

now that I mention it.. alternately you can just open the oil cap while it's running rough and see if it helps.

 

Not in the way he said it would.

 

I don't think the PCV valve is related, i understand it COULD be, so don't crucify me. I agree though that excess blowby would be present. the 3.4 has a Cam Position Sensor yes? I havnt worked on to many of them i can only assume. could he be loosing cam signal and misfiring. or the sensor going bad? i second injector cleaner though.

 

Cam sensor usually would throw a random multiple misfire but when it comes to sensors almost anything is plausible.

 

I agree, Odd that its a inconsistent miss though.

 

Yeah these are the problems you don't like seeing as a tech, makes diagnostic a pita.

 

I

Know a guy who uses gear oil in his motor its a piece of crap 79 celica