DIY Oil Change Observations (2 Viewers)

[Bret_T]

Make sure to open the drain plug and then remove the filter. If you put the drain plug back in before you remove the filter, there is no sump and a considerable amount of oil will remain. I probably got another 1/2Q out when both removed (all 3 actually-as well as the oil cap filler under the hood, obviously).

Would you please elaborate on this as I'm not following the logic behind it? Where would the extra oil remain? Why wouldn't it just gravity feed out of the oil pan plug hole or the oil filter location to begin with?

 

[roaniecowpony]

Would you please elaborate on this as I'm not following the logic behind it? Where would the extra oil remain? Why wouldn't it just gravity feed out of the oil pan plug hole or the oil filter location to begin with?

He's saying a vacuum is behind the oil in the galleys leading to the filter which will keep the oil in the galleys from draining.

Maybe. But opening the oil fill cap should vent the crankcase and allow the oil to flow out. But most crankcases are not that air tight.

 

[cmfhsu]

Just did my 10k mile oil change - I've got a little learning you can hopefully benefit from.

Looks like the oil cap actually requires a pretty meaningful amount of torque - more than I was expecting. I noticed a small amount of oil has been blowing out of my oil cap, likely creating a vacuum leak in my engine. The cap is mighty difficult to remove if you overtighten it, but boy does it take more tightening than I expected. I don't think I did a ton of permanent damage, but I did probably suck some dirt into the engine that didn't need to be in there.

I'd suggest popping the plastic NVH engine cover ~1000 miles after an oil change to look for any oil mist around the filler neck and make sure your cap is sealing as it's supposed to.

On the plus side, now that my oil cap is tight, my car idles like a dream. I was having some rough idle situations where I could physically see the passenger seat vibrate, and today - nothing of the sort. I guess this engine is very sensitive to small crankcase vacuum leaks. It will probably be a bear to undo the oil cap next time I do an oil change, but I guess that's just what I'll have to live with. Wish Toyota had an oil cap with positive stops or that clicky torque mechanism I've seen in some cars.

 

[Bret_T]

He's saying a vacuum is behind the oil in the galleys leading to the filter which will keep the oil in the galleys from draining.

Maybe. But opening the oil fill cap should vent the crankcase and allow the oil to flow out. But most crankcases are not that air tight.

I'm skeptical, but will test that theory at the next oil change, assuming that I remember to do so.

 

[RetiredSteelWorker]

Just did my 10k mile oil change - I've got a little learning you can hopefully benefit from.

Looks like the oil cap actually requires a pretty meaningful amount of torque - more than I was expecting. I noticed a small amount of oil has been blowing out of my oil cap, likely creating a vacuum leak in my engine. The cap is mighty difficult to remove if you overtighten it, but boy does it take more tightening than I expected. I don't think I did a ton of permanent damage, but I did probably suck some dirt into the engine that didn't need to be in there.

I'd suggest popping the plastic NVH engine cover ~1000 miles after an oil change to look for any oil mist around the filler neck and make sure your cap is sealing as it's supposed to.

On the plus side, now that my oil cap is tight, my car idles like a dream. I was having some rough idle situations where I could physically see the passenger seat vibrate, and today - nothing of the sort. I guess this engine is very sensitive to small crankcase vacuum leaks. It will probably be a bear to undo the oil cap next time I do an oil change, but I guess that's just what I'll have to live with. Wish Toyota had an oil cap with positive stops or that clicky torque mechanism I've seen in some cars.

This is an interesting observation. I've had the oil cap off 15 or more times in the seven months of ownership. But as you point out, I have not looked closely (i.e., inspected) under the engine cover for any spray. But now I will.

I have not noticed any unusual tightness in mine.

Years ago I remember reading a description about how oil fill caps have a tapered thread for 1/4 of the first (if you are removing) turn, or 1/4 of the final turn if you are securing, and parallel threads for the remainder. That's what makes the familiar tight feeling for the first 1/4 to 1/2 turn when you are unscrewing. People mostly don't notice, supposedly.

I have a habit of always placing the thread end of the oil cap in a cupped paper towel/shop rag when it's removed. And then wiping the threads before reinserting.

 

[cmfhsu]

The first time I undid the cap (factory installed), I nearly had to get a crescent wrench - it was so incredibly tight. I think it's just the rubber gasket sticking to the filler neck, but man did it take some finger strength to unscrew.

So I tried to tighten the cap less, but it looks like it wasn't quite tight enough. Looks like I'll have to tighten it a good amount and just live with the fact that it'll be hard to undo, as I don't regularly remove the cap the same way you do.