I heard Scotty mention a few times to estimate wear in the engine by measuring the Mass air flow rate in g/s that should be similar to the size of the engine.
Our Honda Odyssey 2013 measures 3.50 g/s the engine is a 3.5L, while our 2012 Nissan measures 2.50 g/s and the engine is 2.0L
Do you guys have any recollection of Scotty's comment on this?
If this is correct what would be the % of wear on this Nissan? of which I'll treat it with the ATS505 once I get it and see if it makes a difference on the MAF rate in idle.
If this is correct what would be the % of wear on this Nissan?
No. It only shows how much air is going into your engine. If it reads more than it should, it just tells you you have unmetered air. Clean the MAF sensor first.
MAF rate g/s and engine wear?
100% unrelated things.
I heard Scotty mention a few times to estimate wear in the engine by measuring the Mass air flow rate in g/s that should be similar to the size of the engine.
This is more of a guideline than an actual rule. My 3.0 Ford Ranger pulls around 4-4.8g/s or thereabouts, depending on air temperature, etc. The fuel trims are only off in a range from 1-3%. 4.8 g/s from 3.0 is a lot bigger than 1-3% error.
Idle speed, air temperature, air pressure, etc. all play a role in how much air actually enters the engine.
Check your fuel trims for how accurate your MAF is reading. If your STFT and LTFTs are relatively close to 0, your MAF is fine. If they're 10% or more +/-, you have an air leak somewhere, the MAF is dirty, or worn out.
I seem to remember talking about how fast your Ranger idles
Yeah, we've discussed it. The engine idles a little faster than other trucks, the engine was designed for an '80s Taurus. Haha. It's a high winder to get torque, most trucks have low end. It actually idles closer to 900 when it's warm, if I remember from the last time I hooked a scanner up to it.
I heard Scotty mention a few times to estimate wear in the engine by measuring the Mass air flow rate
I highly doubt it. When or where did he say that?
what would be the % of wear on this Nissan?
Are you having an issue with the car, or what is the reason for your post?
I'll treat it with the ATS505 once I get it and see if it makes a difference on the MAF rate
How could an oil additive possibly make a difference in the amount of air going into an engine?
I hope you weren't going to pour it into the intake?
I can't help with that video as I haven't seen it. But if you had severe engine wear like bad piston rings the intake air volume would decrease, not increase.
You mentioned trying ATS505. I didn't check to see but I assume you did and whichever Nissan model you have (you didn't say) must have direct fuel injection if you're thinking that ATS505 might help with a carbon buildup issue causing this.
Here again, I didn't check but I guess you checked and found your 2012 Nissan uses Low Tension Piston Rings and maybe you're trying to reconcile carbon buildup on the rings preventing them from fully expanding to seal the pistons to the cylinder walls with the elevated MAF sensor reading at idle.
But this would mimic severe engine wear and again, the intake air volume would decrease, not increase.
Also it would mimic severe engine damage in another way because you'd be burning oil and it would probably be pretty noisy.
Think of each engine cylinder as a lung.
As the piston travels down with an intake valve open, the downward travel of the piston in the cylinder creates suction (vacuum) through the open intake valve from the intake manifold. Air gets sucked in through the air filter and the air volume is measured by the MAF sensor on its way into the intake manifold.
If you had worn piston rings (or stuck low tension piston rings) the downward travel of the piston would create less suction (less intake manifold vacuum) and the MAF sensor would measure less airflow g/s being sucked into the engine, not more g/s (which seems to be your concern).
Of course a clogged catalytic converter would cause the same symptom (lower intake air volume) because as the cylinder tried to exhale through the open exhaust valve on the upward stroke of the piston the clogged cat wouldn't let all of the spent air (now combustion gasses) out of the cylinder. Some would remain in the cylinder and then there would be less cylinder volume to fill on the subsequent intake stroke (lower manifold vacuum, ((lower MAF reading)).
Or an exhaust valve that isn't sealing completely. Sucking air through the exhaust on the intake stroke. (Carbon buildup?) Maybe, but that would cause lower MAF g/s as well as a lot of other obvious issues like low compression (misfiring codes and driveability issues) and backfiring.
So using MAF sensor voltage signals isn't the best way to determine engine wear because the, engine displacement=MAF g/s at idle, formula is a rule of thumb. An estimating tool. Nothing more because there's too many other variables and on top of that it isn't always accurate especially on little 4 cylinder engines.
A dirty or worn throttle body which isn't allowing the throttle plate to close as much as it should will cause a higher MAF g/s at idle. Or a faulty MAF sensor. Or using an aftermarket MAF sensor instead of an OEM. I've seen aftermarket MAF sensors vary from OEM's by as much as 5 g/s at higher rpms.
Luckily, you have the O2 sensor checking up on this.
Look at your fuel trims. If the MAF sensor is outright lying (not a dirty/worn throttle body not closing enough where the MAF sensor is telling the truth about airflow) you'll see it in the fuel trims. In your case they'd be a little negative at idle (because you suspect the MAF sensor is overreporting airflow and the computer would be adding fuel for that airflow and if the MAF sensor was lying the O2 sensor would see too little O2 in the exhaust and read that as a "rich" condition and cut back on the fuel ((negative fuel trim)).
Although I can see how carbon buildup can cause lower MAF sensor g/s readings I can't see how it could cause elevated MAF sensor g/s readings like you suspect.
Consider in that Scotty video in which he used the ATS505 on a direct injection engine (I remember that one), it was rattling terribly and I think it was burning oil. And I was impressed by the results. But that stuff is a "hail Mary pass" and if your only complaint is that your MAF sensor isn't adhering to the "rule of thumb", and your fuel trims look good, and you have no driveability issues, I wouldn't mess with something that isn't broken and I wouldn't try the ATS505 in your case.
