Knock sensor detecting knoks

Sea foam can't hurt. But you shouldn't need it. If you wanna try it they have a spray can now that is easy and less likely to hydrolock then the liquid. And 91 won't hurt your truck, but you don't need it. It's just extra money you really don't need to spend

 

Leave it be. Run regular ass gas and call it good.

 

So, if you didn't have this app (for your phone?), you'd never know there was an issue?

The vehicle's OBD system is designed to set a code and illuminate the Check Engine light to inform you if there is a problem. If that hasn't happened, continue driving. If it isn't broke, don't fix it. Messing with Seafoam, etc when not needed is asking for trouble, IMHO.

Modern vehicles run aggressive ignition timing for max power and mpg. The knock sensor is there to detect spark knock caused by too much timing for the current engine load, fuel octane and quality, intake air temp, etc. If it's knocking under load, the computer adjusts itself and all is well. If it's excessive, the Check Engine light comes on and lets you know.

 

You can run any gas you want to, it is your truck. As I understand your "problem" you were fine until you got an OBD2 Scanner and it said your were getting a knock or few detected by the Knock Sensor and now you are all worried about it. Right.

The knock sensor is there for a reason, It detects a knock and the engine timing is retarded a little to compensate and all is well. It is doing what it was designed to do. Most engines will knock under a load ( even if you do not hear it ).

Step away from the OBD2 Scanner. Your CEL will come on when you have an issue.

Drink a Beer and Relax. You are over reacting to a non-problem.

 

Hey we both posted at the same time with the same response!
Great minds think alike!

 

It's fine.
A properly tuned engine is on the ragged edge of knocking.
The knock sensor detects it and retards the timing before the knock is intense enough to scuff the sleeves or crack the pistons.

It is perfectly normal. If there was a problem, you would have a stored code.

That app was written for people who are doing their own tuning and modifying the operation of the ECU (so their knock sensor may be bypassed).
Delete the app.. you don't need it.

 

Thanks for all the info guys. I will leave it as be and continue to run 91 octane. I appreciate all your input.

 

A tune. Knocking at ANY point is not normal and the more then likely cause of culprit is the fact that the emissions tune to keep this thing so emission compliant is also killing it's actual performance and operation that it is truly capable of.

If you don't believe me that's fine. The 10.8:1 Compression ratio stock GTO I had also knocked like my truck did until I got it tuned, then magically ALL of it went away at every single point in acceleration, and WHAT A SURPRISE! It also burned CLEANER! :O

 

Would be nice, but the only tuners that work on the Tacoma only operate at WOT when in open loop.

 

In the Owner Manual for my 2013 V6 Tacoma it states that light knocking under acceleration -like merging onto the freeway- is normal. Are you saying that Toyota knows there's a knock and just ignores it with that statement?

 

Is the new 2013 GDI/ direct Injected?

 

The app also doesn't measure knock the way the ECU does. It does some strange things to 'think' it detects knock. For instance, your knock sensors are designed to pull timing when they detect certain harmonics of knock. The knock sensors themselves will always be detecting knock - however the ECU will know which frequencies of knock are 'real' pre-detonation, and thus make corrections to timing. I don't think the app is going to be as smart as the factory ECU in doing this.

Best way to see if you are getting real knock is to measure knock retard with a real scanner. Knock retard is showing what the actual ECU is doing to correct real knock. And yes, up to a certain point, some knock is perfectly normal, and the ECU corrects this by reducing timing. It does it almost instantly, which protects the motor. A few degrees of knock retard is fine.

And BTW, knock mainly happens under load, which is generally in open loop, which does not mean WOT. Your truck spends quite a bit of time in open loop, even if you don't have your foot on the floor. If you truly have real knock, you certainly don't want to go to a lower octane fuel. Higher octane is not just for higher compression. It's for knock resistance, regardless of compression. It's just more usual that a higher compression motor will pre-detonate more on the same octane as a lower compression motor. If you don't truly have knock, then the higher octane is a waste.

 

Essentially. Yes. I really don't give a hell what the owners manual states. Toyota tunes their engines to be as emissions compliant and as emissions free as possible. This more so applies to California vehicles due to stricter emissions regulations. Just because they might be compliant and cleaner burning DOES NOT mean that the engine will be running optimally under all conditions. I am clearly aware and know why mine does it and is more noticeable.

I believe this is exactly how my GTO was tuned as well. Not a bad way of tuning it. If you can address the tune, regardless of which way you tune it, then it is highly likely that it will more then likely rid the engine of any prior knock it had during driving.

 

I have ran race fuel in mine. It ran fantastic on 100 octane, and I also tried some C-12. I would say the C-12 (120 octane) was a waste, but the 100 was perfect. A rule of thumb for racing is 10:1 compression ratio will get the best performance on 100 octane. 12:1=120 octane, etc. Btw, race fuel is $14 a gallon or so. I run non ethanol premium (91) daily. Try a tank and do the math on it. I bet you will find that it is the cheapest per mile, and you get a better running engine to boot.

 

I have a wideband gauge installed. The ECU tries to correct the AFR to stoich (14.7:1) when in closed loop. The only time that happens is at idle, decel (fuel cut) and light cruise, the rest of the time it runs on my tuning. I just use an URD Maf Calibrator. I tune to 13:1 under 3000rpms for economy, then transition to 12:5:1 from 3000-4500 and 12:1 4500-redline. It runs like a raped ape, no knocking (at least on 91).

 

My truck takes 87 octane. If your engine is designed to run 87 stock, higher octane does nothing unless you raise the compression ratio. What will change performance is ethanol free, and race fuel, which is also more refined then pump gas. I've tried my truck on 89 once. Got terrible mileage, I don't know why. Went back to 87 and get 16-17 city consistently

 

THIS right here. This is the best AFR to run across the rpm ranges. He has done some great tuning.

 

The 1GR-FE will run on 80 octane pemex hand pumped out of a rusty barrel too, but that doesn't mean you will get the best performance from it. Also if you change octane it takes a while for the long term fuel trims to adjust. Try filling up with the best fuel you can find and then pull the battery cable for a few minutes. It will relearn and you WILL see more power and better mileage. It's a fact these trucks are designed to run best on 91!

 

Well I know the 2nd gens are. I'm a 1st gen creeping on a 2nd gen thread lol . Got the ole trusty 3.4L

 

Your engine has fairly high compression ratio as well at 9.6:1, and was also designed to run best on 91 octane. Read it for yourself- http://www.mr2.com/files/mr2/techinfo/Random FSM Data/engine5vzVS3vze.pdf