Checking for engine pinging under load with an OBD scanner without a code?

little bit of history. My truck has light engine pinging/knocking issue at load (6th gear, low rpm seems to be where mostly present and only audible from the inside with windows shut). No trouble code present. 7500 miles (this started at around 3000 miles). I tried a tank of premium gas 93 octane still have pinging noises. oil level is perfect and I changed it two days ago with mobile 1 full synthetic 0w-20. I have been to a Toyota dealer and rode with a service manager who insisted he does not hear the pinging/knocking noise. I am going on a test drive with another dealer next week. I just bought a OBD scanner tool and wanted to know if I can check for engine ping/knock using the live data feature without a fault code present. I am hoping if there is a way then I can show the data instead. Apparently some pinging/knocking on this 5.7L iForce is normal (in the manual) but it is annoying as hell. some knocking $50k truck at this low miles should not be a normal. I have never experienced this BS before.

any insight will be appreciated.

 

These engines are noisy, so are you sure you're not just hearing a diesel-like knock sound that every Tundra makes?

The only way I can think of to monitor knock via OBDII without a CEL would be to watch fuel trims (short term and long term) for any lean condition. I'm not sure if Toyota has OBDII PIDs for knock sensor feedback.

There's a guy on here, ViktorG, who is tuning his supercharged Tundra. You could view his threads and YouTube channel to see how he's monitoring knock for tunes. He's also in the process of releasing a tune package.

 

@BecauseRacecar

Yes its not the diesel like clatters and I am aware that this engine is not the quietest out there. it's sounds like if you have a bad fuel.
going back to checking for lean condition sounds like a potential so thanks for that.

 

most engines have knock sensors. if they sense pinging or predetonation via vibrations the sensor sends a signal to PCM to retard timing. If you want to test pretty simple find the sensor and tap next to it, you should hear a change in idle speed as the timing is altered.

 

I don't see a knock sensor value in TorquePro, though you can monitor timing which is one of the displays I always watch (and could monitor AFR to make sure it's nominal). However if you're getting knock it won't necessarily retard instantly, but you might be able to see it on the timing. With HP Tuners you can monitor knock, but that's not cheap. Pinging seems highly unlikely, but shit happens.

 

you don't need a computer to test knock sensor reread my post

 

The knock sensors are under the intake manifold behind that sound insulation though....

 

I don't think OPs question is if knock there's knock sensors, he thinks he's experiencing knock.

 

I pushed my truck hard when I was test driving it (didn’t know I was going to end up with it). Maybe I can reset the ECU to have it relearn to see if the slight knocking goes away? Thought??

 

Yes, disconnect battery terminals, usually leave them off overnight. I would run a tank with fuel system cleaner, SeaFoam or whatever, then fill up with 93 octane, and remove the battery terminals to reset. See what happens from there. Looks like you can watch KCLV with obd fusion, worth watching during the process, but doubt anything helpful proving your issue at a dealership.

 

If you are pinging with 93 you have a major issue. Was there any change at all with 92 vs lower octanes?

There should be an OBDII bluetooth system that would be able to show you either timing retard or knock sensor inputs.

 

I am using Foxwell NT301 scanner.
I pulled the short and long term fuel trim numbers this morning. ambient 74F. Numbers look ok to me

STFT1 0.8 - 1.6
STFT2
LTFT1 1.6

 

got posted before I finished typing....

At idle 683-693RPM Operating temp 206F

SHRTFT1(%) 0.8 - 1.6
SHRTFT2(%) 1.6

LONGFT1(%) 1.6
LONGFT2(%) 2.3

MAF 5.01
Spark advance 11.0 - 12.5
IAT temp 36F


At 2000 RPM

SHRTFT1(%) 0.8 - 1.6
SHRTFT2(%) 0.0 - 0.8

LONGFT1(%) 0.8
LONGFT2(%) 1.6

MAF 13.57
Spark advance 33.5
IAT temp 36F

 

if the knock sensors arent working then he will have knock. the knock sensors eliminate the knocking and pinging

 

I’ll go a different direction…do you think it could be something else? Maybe something else causing the sound? Heat shield on exhaust? Exhaust leak in general?

Are you experiencing any power loss?…truck will automatically pull timing if it senses detonation and that will decrease power output.

These engines are designed to run on 87…so if it is pinging on 93 as bad as you think it is, there is a significant problem. Given the fact that you have zero indications other than what you think you hear, it makes me wonder if you are chasing the wrong issue.

6th gear, low rpm when under load? Typically, pinging is really noticeable when the engine is under load and anywhere in the powerband…6th gear, low rpm tells me you are cruising down the freeway, not much load there…another reason why I think you are chasing the wrong thing. What does it sound like when you put the engine under load? It should be really noticeable then.

Have you looked under the truck to feel around for anything loose? 6th gear, low rpm could be the right spot where something vibrates or resonates and it sounds like pinging.

Or, what you may be hearing is normal (as stated in the manual) or within allowable tolerances of the system and why the truck isn’t throwing a code. But 93 Octane should have taken care of that, so that’s why I am thinking it could be something else. When you ran 93 did you put in a full tank? Remember, there is a significant amount of gas remaining the 26 and 38 gallon tanks when they are on “E”. (Trying to bound a few variables.)

 

I don't think that's necessarily true. From what I've read knock can still occur even with KR happening. The KR might not ramp up fast enough, or if there's only minimal advance to begin with so it can't retard much then knock could still happen. I don't think its clear cut of "if the knock sensors work then knock won't happen".

 

if knock sensors work and you may have an short duration ping (1 second) but not continuous as the sensor job is to send a signal to PCM to retard timing and negate ping/vibration.

if the ping is so light you cant hear it then knock sensor wont sense and no harm done

all that said I can make my lexus gs300 ping for a second with quick blip of throttle but it ceases. my tundra I cant make it ping ever even trying with quick small blips of throttle.

 

IAT is reading half ambient temperature. That’s low. It’s usually in the low 100s on a warm engine.
Sure that’s not Celsius?
Also, are the 2k readings parked or driving?

 

Sorry yes IAT temp was in Celsius so 96.8F. 2k rpm was parked.

 

Yes I checked for heat shields etc. no power loss. I filled with 93 octane with 10 miles to empty. I can make the engine ping pretty much every time I blip into the throttle or steady 1200-1500 rpm in 6th gear.

 

I have to agree with @Crunch527 on thinking it may be something else.
If you can get it to make the noise while parked I'd crawl underneath and in the engine bay and check everything you can think of realtime to see if you can figure it out. Heatshields, skid plates, exhaust flanges, thin metal brackets, anything that can move with vibration that you can get a wrench on. At least satisfy yourself that its not something simple, cheap and easy before you stress yourself out over something more serious.

 

From what is presented...It looks like the ecm is being fed the wrong information about engine load and cranking the timing. The fuel trims and timing don't look bad but that is a static look. What you describe above would need a trend over throttle position.

The one thing that pops out as a potential variable is the MAF being defective.

 

has anyone actually done a ECU full reset by disconnecting the battery cables and completely drain out all power to ECU?
I expect radio preset, home link garage, clock to be reset but anything else like idle speed will need to be reset? After reset, drive i would normally so the ECU can rerun? my truck is 2021 so just trying to be careful and not cause any self inflicted harms. I am hoping reset will have ECU relearn the fuel trims and timing. Thanks

 

it is simple and worth a try.

 

The ECU will relearn via normal driving. The idle will probably be low for a short while is all. Some say idle in park for 5-10 minutes, then 30-60 seconds in gear. Afterwards drive normally.

 

Quick update. First time I disconnected only the negative battery cable and put jumper wire between the negative cable and positive post/wire for about 30 min. Kept the headlight switch on for good measure . Clock did reset as well as the trip computer but no impact to idle speed. Drove for about 40 min still hearing pinging.

Second time I disconnected both positive and negative and put jumper wire between two battery cables and isolated. Again turned on the headlamp for good measure and lest for an hour. This time clock did not reset but trip computer did. No impacts to idle speed. Drove for about 30 min but pinging still exists. Sounds like I have to try leaving the cables off longer. Geez it may have some other back up power??????

 

2nd time left the cables off for an hour

 

Wanted to give an update and share what I've learned. I was able to get the shop foreman from the 2nd dealer to ride with me and agreed that he hears what he described as "spark knock" his comment was that it is normal on 5.7L iForce (I called BS on this but even the Toyota manual said that short and slight knock is normal) Unfortunately they did not have another Tundra in the lot for me to test drive. After I came home, I did a ECU reset (Disconnecting both battery cables and tied them together for about 3 hours) and it appears to lessen the "spark knock" condition. I've tested with 87 Octane). I didn't have to reset the idle or anything else (Key on --> off --> Key on --> engage parking brake --> start the engine --> Trans in D --> back in park and idle for about 10 min is the process I followed). Drove next 50 miles easy with no harsh accelerations or braking for the ECU to relearn. I hope this helps out someone out there. Thanks for all your comments and input.

 

Toyota very very smart. Their knock sensors use a specific frequency to adjust timing, hitting nearby with a hammer is not going to cause the knock sensor to react unless its the same frequency as pre-detonation. Toyota knows there engines are noisey.

 

Watching timing in real time can show it. I've seen it retard past 0° in low rpm 6th when it pings.

3 ways I've found to stop it on my truck:
-premium gas to mask the problem
-hook up to a trailer and take a trip to work it and get it hot enough to burn the carbon out
-if you have a ffv, a couple tanks of e85 clean the carbon out of engine as well if not better than seafoam.

It's like a Ford 8N. 99% of the time it's not exercised. Those old tractors would run like dog crap in the spring until you plow the field, running it so hard the exhaust manifold glows so hot it illuminates the front tire at dusk when it's time to call it quits. Then it would run awesome the rest of the season.