Hey oppo, how do you know if your engine is knocking?

"YSI-what can brown do for you" (ysi-what-can-brown-do-for-you)
09/25/2013 at 21:55 • Filed to: None

I only need to know for safety. As you may know, some FRS/BRZs have experience engine failure due to DI system. Usually what happens is, one of the ports does not work(randomly) and so one of the cylinders doesn't fire properly. Anyways, how can I tell if the engine is doing that? To show gratitude to your service to the Indian community I present to you NOTHING!!!

DISCUSSION (55)

Corey CC97, MAZDA DPI IS STILL BAE JOESTACTIV JOESTACTIV JOESTACTIV JOESTACTIV VISIT FLORIDA RACING LIVES FOREVER IN OUR HEARTS > YSI-what can brown do for you
09/25/2013 at 21:58

Trading nothing for advice? You drive a hard bargain...

Unfortunately, I have no real experience with misfiring engines. Sorry I couldn't be of help.

getchapopcorn > YSI-what can brown do for you
09/25/2013 at 21:58

Is somebody there when you open the hood?

YSI-what can brown do for you > getchapopcorn
09/25/2013 at 22:00

Can't you hear knocking when it happens?

YSI-what can brown do for you > Corey CC97, MAZDA DPI IS STILL BAE JOESTACTIV JOESTACTIV JOESTACTIV JOESTACTIV VISIT FLORIDA RACING LIVES FOREVER IN OUR HEARTS
09/25/2013 at 22:00

Will pictures of women work?

Nick, Drives a Cobalt LT > YSI-what can brown do for you
09/25/2013 at 22:01

You will fucking feel it on a 4 cyl...Trust me

YSI-what can brown do for you > Nick, Drives a Cobalt LT
09/25/2013 at 22:03

Well thats good I guess. I haven't felt a thing yet. Is there a certain sound it makes. When I googled it, it said you can hear a pinging sound.

Corey CC97, MAZDA DPI IS STILL BAE JOESTACTIV JOESTACTIV JOESTACTIV JOESTACTIV VISIT FLORIDA RACING LIVES FOREVER IN OUR HEARTS > YSI-what can brown do for you
09/25/2013 at 22:03

Pictures of women always work. But I seriously can't really help you with your dilemma. Can I still have the pictures?

YSI-what can brown do for you > Corey CC97, MAZDA DPI IS STILL BAE JOESTACTIV JOESTACTIV JOESTACTIV JOESTACTIV VISIT FLORIDA RACING LIVES FOREVER IN OUR HEARTS
09/25/2013 at 22:06

That's okay, not everyone can help me. You can haz picture, but I role with no nudity. . . so prepare to be disappointed or pleased. . .

Kinja'd!!!

pdthedeuce > YSI-what can brown do for you
09/25/2013 at 22:07

often sounds like a hammer hitting metal, hence the term "ping".

YSI-what can brown do for you > pdthedeuce
09/25/2013 at 22:09

Well I haven't heard that, so that is a good sign.

pdthedeuce > YSI-what can brown do for you
09/25/2013 at 22:10

yup. sometimes it's a more substantial sound, but it often starts with the ping.

YSI-what can brown do for you > pdthedeuce
09/25/2013 at 22:11

What is the worst that can happen when an engine starts knocking?

deekster_caddy > YSI-what can brown do for you
09/25/2013 at 22:12

how to describe pinging to somebody who has never heard it... it's kind of like a light grinding/tapping sound. Can be a bit like a growl. As detonation gets worse, the 'pinging' gets louder and deeper, and eventually changes from "Ping" to "Knock".

I don't know about the FRS/BRZ but other cars you can connect a scan gauge to the OBD-II port and monitor the knock sensor or the ECM parameter called "Knock Retard" or how much timing the ECM is trying to take away because it's detecting knock. A knock sensor will detect knock and cause the ECM to reduce ignition timing long before it becomes audible to your ears. I'm not sure on the japanese models how it reports that, my experience is from american cars, I'm not sure exactly what japanese cars call these parameters but they should be accessible.

TheOnelectronic > YSI-what can brown do for you
09/25/2013 at 22:13

Never had knocking that I know, but I believe modern cars have knock sensors that will prevent damage by retarding engine timing.

Also, direct injection systems, at least the one on my car, do have a definite "tapping" noise that they make.

pdthedeuce > YSI-what can brown do for you
09/25/2013 at 22:13

it can be bad...

Kinja'd!!!

Corey CC97, MAZDA DPI IS STILL BAE JOESTACTIV JOESTACTIV JOESTACTIV JOESTACTIV VISIT FLORIDA RACING LIVES FOREVER IN OUR HEARTS > YSI-what can brown do for you
09/25/2013 at 22:16

I am pleased. No nudity doesn't bother me.

YSI-what can brown do for you > TheOnelectronic
09/25/2013 at 22:18

Yeah you can hear the clatter from the DI system. That isn't worrying though.

You would think modern cars do that, but for some reason, it doesn't do that in the FR-S. . . sometimes. It depends on when your car was made. Mine was made before they patched things up.

It's a "Porch-uh" > YSI-what can brown do for you
09/25/2013 at 22:20

You'd feel it, but it's not always a "pinging" sound. Sometimes it's deeper depending on the motor. Also, modern engines will throw a code immediately and you'd get a check engine light.

If the injector isn't firing sometimes, you wouldn't get a knock, you'd get a dead cylinder (at least on the cycle it didn't spray). If it's spraying late or early so much that some of the fuel is getting out the valves you would get a lean condition on that cylinder (that's bad, but not knocking).

Knocking would happen if the ignition timing was off really bad and you get pre-detonation, so the piston is on its way up, but the explosion tries to push it back down before it reaches the top. That's what could do damage to the rod bearing, con rod, or wrist pin.

desertdog5051 > YSI-what can brown do for you
09/25/2013 at 22:22

When you hear a noise at the front door and you look out and there is a motor out there. :)

YSI-what can brown do for you > It's a "Porch-uh"
09/25/2013 at 22:25

So is there a difference between detonation and knocking? Cause I was reading up on this, and a lot of the forum members talk about the engine detonating on faster shifts.

Dunnik > YSI-what can brown do for you
09/25/2013 at 22:29

I'm hardly a mechanic, but I think you'll know. At the risk of pointing out the obvious, it's called knocking for a reason: you'll hear it, and/or feel it. Ergo, if you haven't experienced anything like that yet, then perhaps you can assume that there's no issue. I suppose if you're really concerned, you should take your Toysubie to the dealer - it is under warranty, after all (unless you've extensively modded it, which may void the warranty).

YSI-what can brown do for you > desertdog5051
09/25/2013 at 22:29

I am not sure if I should murder you, or hug you. You decide!

YSI-what can brown do for you > Dunnik
09/25/2013 at 22:30

Only have an exhaust system on the car, so they can't void the warranty for that. PLUS it is a problem from the factory, not caused by any sort of mods, so they kind of have to honor it.

YSI-what can brown do for you > Corey CC97, MAZDA DPI IS STILL BAE JOESTACTIV JOESTACTIV JOESTACTIV JOESTACTIV VISIT FLORIDA RACING LIVES FOREVER IN OUR HEARTS
09/25/2013 at 22:31

Sometimes people expect pics of ladies to be nude, so I wasn't sure what you were expecting really.

desertdog5051 > YSI-what can brown do for you
09/25/2013 at 22:33

Oh, I don't know. I guess I would probably prefer the hug.

YSI-what can brown do for you > desertdog5051
09/25/2013 at 22:35

Will internet hug work?

It's a "Porch-uh" > YSI-what can brown do for you
09/25/2013 at 22:36

It's technically called "pre-detonation," since it should be "detonating" just fine during normal operation. "Pre" because it's happening before it's supposed to. Usually pre-detonation happens when somebody has a high compression motor (NA or forced induction) and puts in low octane fuel, which doesn't resist detonation by pressure like fuels with higher octane ratings. Modern motors have knock detectors (even my '98 Chevy K1500 has one) and will retard the ignition timing to prevent detonation (but reduces fuel economy and performance).

Pre-detonation is what causes the motor to "knock" since that cylinder is being forced back before it's ready to go. So looking at one of those animations of a pistons moving up and down, imagine putting your hand against one of the pistons while it's on it's way up. Like you were trying to stop the crank from rotating by pushing back again that piston on the up stroke.

Again, a fuel injection issue wouldn't cause a pre-detonation or knocking. I also don't see how "fast shifts" would cause that either, unless the ECU does something with the timing when the clutch is in, which would be really weird.

desertdog5051 > YSI-what can brown do for you
09/25/2013 at 22:41

Works for me, brother Oppo.

Corey CC97, MAZDA DPI IS STILL BAE JOESTACTIV JOESTACTIV JOESTACTIV JOESTACTIV VISIT FLORIDA RACING LIVES FOREVER IN OUR HEARTS > YSI-what can brown do for you
09/25/2013 at 22:44

I was basically expecting what was in your picture and the gif below. By the way, the gif is my thank you gift to you.

Kinja'd!!!

RotaryLover > YSI-what can brown do for you
09/25/2013 at 22:53

When it starts making knock knock jokes.

YSI-what can brown do for you > It's a "Porch-uh"
09/25/2013 at 22:55

I think it is the ECU. Basically what happens is, the ECU isn't prepared for such a fast shift so then it doesn't tell the injectors to do anything and thats when the knocking happens. Over time the seals start to wear out and then it just happens constantly. Does that make more sense? Basically it is Toyota's fault that the engine could be failing, yet the dealers won't do anything about it until you get a CEL. By that time it might be too late, so you are going to have to go to the aftermarket to get this sorted out(which you can). . .

YSI-what can brown do for you > Corey CC97, MAZDA DPI IS STILL BAE JOESTACTIV JOESTACTIV JOESTACTIV JOESTACTIV VISIT FLORIDA RACING LIVES FOREVER IN OUR HEARTS
09/25/2013 at 22:56

Fuck yeah! Gifs!!! Only one letter away from gift!

YSI-what can brown do for you > desertdog5051
09/25/2013 at 22:57

*hugs*

YSI-what can brown do for you > RotaryLover
09/25/2013 at 22:57

Ha. Haha. HAHAHAHAHA. HAHAHAHAHAHAHAHHAHAHAHAHAHA. Observe desertdog's post.

RotaryLover > YSI-what can brown do for you
09/25/2013 at 23:02

Dammit! I blew my chance to be original...somewhat...argh...

Corey CC97, MAZDA DPI IS STILL BAE JOESTACTIV JOESTACTIV JOESTACTIV JOESTACTIV VISIT FLORIDA RACING LIVES FOREVER IN OUR HEARTS > YSI-what can brown do for you
09/25/2013 at 23:03

One hell of a gif, too. I've been staring at it for like five minutes now. Dat smile...

Squid > YSI-what can brown do for you
09/25/2013 at 23:15

Have you ever started a car up on brake cleaner or starter fluid with out the fuel pump running? When you do that and the motor starts to stall out you hear knocking. Sometimes it isn't that loud and your ECU should pick something up via the knock sensors, they will generally retard ignition and other wizardry is performed to stop the knocking by adjusting fuel maps and such. If the knock is bad it will throw a code, I'm not sure if it is one of those flashing engine light codes though. With a four banger you'll feel roughness and possibly some hesitation. Most times knock occurs it isn't too loud, and most motors will knock a little bit in their service life, high quality fuel helps aleviate knock. But if the knock in the FRZ's is taking motors out, I'm pretty sure you'll feel it and know it if it happens. Since it is an issue if you get any MIL's on your dash, park the car and call a tow truck to not take any risks, or drive it till it blows up and be out of your car for a while while the warranty is putting a new motor in your car.

Here is a video of rod knock.

YSI-what can brown do for you > Squid
09/25/2013 at 23:27

It isn't the knocks that cause the engine failure. It is the ECU which isn't telling the DI system to put more fuel in, which causes the knock, which in turn causes DI seal failure which in turn causes more knock until engine failure. . . does that make sense? Either way, I need to know if there is knock.

I haven't felt anything, or even heard anything, so that is a relief.

It's a "Porch-uh" > YSI-what can brown do for you
09/25/2013 at 23:27

If there's no fuel in the cylinder, it's not knocking. There's probably a shudder or a stumble from the engine because there's no explosions going on in there, but it's not a knock.

What seals are wearing out?

Decay buys too many beaters > YSI-what can brown do for you
09/25/2013 at 23:32

So I take it you have checked your ECU calibration? and fall outside of the most recent build?

There are several things at play in this issue, one critical part is gas quality. Do you have access to 93+octane at the pump? That will help quite a bit to prevent knock in the FA-20. Where I am we only have 92 octane :( and we cannot pump our own gas :(

Also are you looking for a test of whether your DI seals are toast?

YSI-what can brown do for you > It's a "Porch-uh"
09/25/2013 at 23:34

The seals to the injector in the cylinder.

It isn't that there isn't fuel in the cylinder(there is because of the other fuel injector outside the cylinder) it is just that there isn't enough fuel, so it runs lean. This is what probably causes the seals to be destroyed. I am not an expert but that is from my understanding.

YSI-what can brown do for you > Decay buys too many beaters
09/25/2013 at 23:38

I haven't done the test yet. I am planning to do it when I go back home for the long weekend. So we will see then. I don't think I have any problem.

I do have access to 93 octane, which means moar powah!!!! I also would like to know about a test to see if my seals are okay, is there such a thing?

Mattbob > YSI-what can brown do for you
09/25/2013 at 23:40

Check the door.

Sorry. Had to.

YSI-what can brown do for you > Mattbob
09/25/2013 at 23:41

GAWD! You are like so original. But seriously, you were beaten to the punch.

It's a "Porch-uh" > YSI-what can brown do for you
09/25/2013 at 23:44

So it has direct and port injection? If there's some fuel in the chamber, and ignition timing is correct, you'd get a "lean knock," which is actually just a misfire. You still get a stutter from the motor, but it does different damage. Then you're talking possible melted pistons.

Kinja'd!!!

YSI-what can brown do for you > It's a "Porch-uh"
09/25/2013 at 23:46

That sounds like what happened to some people. . . I don't like the possibility of that. It is just killing me on the inside to get this fixed. I know nothing has happened to me yet, but still.

Decay buys too many beaters > YSI-what can brown do for you
09/25/2013 at 23:47

One way I've seen people showing that their seals are shot on the forums, is a loud popping noise coming from under the hood when the throttle is blipped at idle.

http://www.ft86club.com/forums/showthr…

YSI-what can brown do for you > Decay buys too many beaters
09/25/2013 at 23:49

Thats good, I don't have that problem. Although the guy with the supercharger might be screwed. The dealership should still honor the warranty because it is a problem from the factory, but they probably won't.

Decay buys too many beaters > YSI-what can brown do for you
09/25/2013 at 23:53

Agreed, but a lot of the Subaru guys are getting screwed by the SOA warranty... Glad I got the Toyota, they didn't give me any shit at all about my bolt ons when I went in for my replacement fuel pump (fucking crickets came back last week though).

Squid > YSI-what can brown do for you
09/26/2013 at 00:12

But really the knock is what kills the motor. Sucks that there is DI problems with those motors. Hopefully it gets sorted out with a TSB and an easy fix. So is it the DI system that fails first or is it just the ECU that starts out being the root issue with a bad calibration? With the finicky DI system I would stay away from low volume, low quality gas stations and pour some techron in the tank every so often to keep the injectors clean and seals soft.

Well regardless that video is an example of catastrophic knock that is the end of a motor.

YSI-what can brown do for you > Decay buys too many beaters
09/26/2013 at 00:34

Neither did my dealer. Luckily the law is on our side!

Squid > YSI-what can brown do for you
09/26/2013 at 00:43

Man, it seems like you just need to be running the highest octane possible in this car. Sucks that if I had one, it would probably have a dead motor due to this problem just because of the way I drive. My lil roadster sees 7,000 RPM every time I drive her. It seems like if you hear any popping in the engine compartment get it to the dealer. . . I can't wait till all of these issues get solved and the twins will be out of their teething stage by the time I'm ready to buy one. . .

Bruno Martini > YSI-what can brown do for you
09/26/2013 at 11:13

Knocking/missfire sounds like gravel hitting hard metal. Or a can with pebels being shook. Your knock sensor should be keeping track. Got to a reputable tuning shop and they will give you knock count. The ecu is supposed to keep track of knock and try to prevent it.

Tentacle, Dutchman, drives French > It's a "Porch-uh"
09/28/2013 at 08:22

Hang on, now I'm confused. As far as I understand it, combustion is not the same as detonation. An internal combustion engine, well, it combusts. The flame front advancing through the fuel/air mixture is, by comparison, slow. Detonation is when part of the fuel/air mixture explodes, with its flame front forming a high speed shock wave.

So how can detonation be just fine during normal operation?

It's a "Porch-uh" > Tentacle, Dutchman, drives French
09/28/2013 at 22:47

You're correct, the normal explosion/fire/bang-bang in a motor is "combustion." I was just being technical that the issue at hand is referred to as "pre-detonation," in that the air/fuel mixture is exploding before the spark plug sets the whole thing off.