Anyone running 0W-40 in their 100 Series? (2 Viewers)

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Hey guys,

Wanted to see if anyone was running a 0w-40 oil in their 100 series.

I've got an 05 with 294k miles. Runs strong and looks very clean inside (just had the valvcovers off to replace the gaskets).

I'm hearing an ever-so-slight knocking or tapping noise (tend to be very parranoid unfortunately) and am thinking maybe the tolerances have started to loosen up.

I'm curious if anyone else has stepped up from the 5w-30 Toyota spec and if so were you happy with it?

Thanks for all your inputs in advance.

-James
 
Yes, I run mobil 1 0w40 in all of my cruisers and have for the last 7-8 years. If you have a tap that is not an exhaust manifold crack, it is likely in the valvetrain. all but one of my 4 2uz's has cold start piston slap, but that goes away in 30 seconds or so. Dont count on oil fixing it, but at the same time dont hesitate to run 0w40. I only know about mobil 1 0w40, but do your research - it is one of the best gas engine oils out there. It is also one of the thinnest 0w40's, if I remember right the actual viscosity is more like 0w36. If you really dive into the weirdness of oil weight ratings, the 0w40 is closer to being a 5w30 than mobil 1's 5w30 is.

For the last 30 years or so, toyota engineers have not really spec'd oil for a motor - the EPA does that indirectly. Everything is going to lighter oil to increase efficiency and stay within epa regulations. Newer motors are designed with tighter clearances to run 0w20 and still make adequate pressure, but the older motors like the 2uz were not - thats one reason they last so long. Look at the discrepancy between the reccomended oils for the US and AU for the 2uz. The reccomended range is 5w30 to 20w50 on the exact same motor - just depends if the EPA is in the same place as the vehicle is and how hot the climate is. That being said, I would not run anything over a 40wt on a 2uz unless you are in a 120+ degree climate all of the time.
 
Hey guys,

Wanted to see if anyone was running a 0w-40 oil in their 100 series.

I've got an 05 with 294k miles. Runs strong and looks very clean inside (just had the valvcovers off to replace the gaskets).

I'm hearing an ever-so-slight knocking or tapping noise (tend to be very parranoid unfortunately) and am thinking maybe the tolerances have started to loosen up.

I'm curious if anyone else has stepped up from the 5w-30 Toyota spec and if so were you happy with it?

Thanks for all your inputs in advance.

-James
I wouldn't consider going to 0-40 a step up from the 5w30 toyota recommended viscosity..

That's not to say you can't do it....Oil, tires, suspension...three topics that folks spend way too much time thinking about.... If you have a slight tapping or knocking, well first I'd try to narrow down that diagnosis a bit more , but getting thinner 0W oil flowing in there certainly wont help.

How long have you had your 100 series for? Have you heard other 2UZ's run? They aren't the quietest motor and under load can sometimes can produce some strange working noises
 
Thanks for the input guys. Yes, understand both schools of thought- escpecially that from @peacesells63. Wide range of vicscosities Toyota themselves recommends overseas for the same engine with the same facotory tolerances. Makes you think..... and that was my original driver for reaching out to you guys.

@Mike NXP the noise does not happen at all while cold. I hear it only when up to temp at idle and it kinda seems to come and go, very faint though. Have had this 05 for about 6 months, but grew up in the back of my dad's 98 (year I was born and that's why he got an SUV). I was working on that one at age 10 or so and still am today. Familiar with the common valve train noise and cracked exhust manifold tick.... the sound I'm getting is different.

My logic with the 0W-40 was to stay as close to the factory spec as possible- just a little thicker when hot. If anything, I would have thought a 0W would flow better and provide better protection on a cold start than the 5w-30. And shear down close to (and just above) a 30 wieght when up to temp.

Thanks again everyone for the inputs 👍
 
Maybe look into a valve lash adjustment.
 
Get a mechanics stethescope or a long piece of metal to listen around and figure out where the tick is coming from and if its at cam or crank speed. All of my 2uz's have some degree of valvetrain noise. They are very quiet motors overall, so valve noises tend to stand out. Bad idler pulley bearings or a bad fan bearing can somtimes make tapping noises too.

I had the same logic switching to 0w40, that is the only oil I run in gassers now. Even run it in my snowblower and pressure washer.
 
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@hoser and @peacesells63 thanks both for the advice. Will look into those. In the meantime, it’s pretty hot down here in FL right now so would be a good time as any to give Pennzoil Ultra Platinum 0W-40 a try.

Will let you guys know how it goes.
 
Hey guys,

Wanted to see if anyone was running a 0w-40 oil in their 100 series.

I've got an 05 with 294k miles. Runs strong and looks very clean inside (just had the valvcovers off to replace the gaskets).

I'm hearing an ever-so-slight knocking or tapping noise (tend to be very parranoid unfortunately) and am thinking maybe the tolerances have started to loosen up.

I'm curious if anyone else has stepped up from the 5w-30 Toyota spec and if so were you happy with it?

Thanks for all your inputs in advance.

-James
I'm currently running Euro-spec Mobil 1 0-40 in the summer, it's widely regarded as an excellent oil, has Porsche A40 approval, etc. Note that it's thicker (even at most startup temps that your car will actually see, including cold mornings) than 5w30 despite the lower winter viscosity designation.* It will NOT be thinner at startup unless you start getting close to the pour points of these oils (like in the -35F to -45F temperature range).

However, I seriously doubt that it will do anything for the knocking noise that you hear, especially if it turns out to be a loose or cracked exhaust header.

Also keep in mind that these engines are substantially under-stressed and are very easy on oil, and the 5w30 works well for the vast majority. Keep the cooling system in good operation and the motor will almost certainly outlast the rest of the vehicle. And if you actually do have, say, a rod knock, then the above goes out the window of course.

*Here's a short read that goes into more detail: 5w30 vs 0w40; that guy has a very dense blog if you want to dive deeper.
 
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