I've noticed in the last few months that when I press down on the gas (usually in higher gears) and put a little stress on the engine, I an hear these faint metallic pings (maybe ping is too strong a term, it's very subtle). It started out when I'd really be giving the car some gas, but now it occurs when I accelerate even moderately.

It's been doing it less recently with the cooler weather, I noticed it more with the warmer temps.

Could this be the sparks detonating too soon? I say this, since a friend of mine suggested it after I described the sound.

He said I should fuel up with some higher octane and see if that fixes the problem.

Any thoughts on this? How hard is it to diagnose something like this? Is there something I can rent at Autozone to check it?

Thanks.

The first thing you need to do is replace the stereo, then the speakers, and turn it up. (IMG:style_emoticons/default/harhar.gif)

It sounds as though you have an exhaust heat shield coming loose. Try to slide under the car(and the hood) and tap on the aluminum plates around the exhaust. The header and cat should be wrapped around and the rest are between the exhaust and the floor of the car. If one is loose you'll hear the difference.

This post has been edited by rsquared: Oct 22 2009, 11:11 PM

Hahaha! Bust out the ghetto blaster and problem solved.

I will take a look at it. It really sounded like it was internal to the engine. Like almost metal popcorn sound (I just invented that description).

Mine did the same thing ..when I put regular I hear those detonating sounds( regardles of petrol station..petrocanada, shell, ultramar ...) Just put the 91 octane one .It cured the problem and the engine is so smooth

If you installed a better grade of plugs maybe the heat range of them is to high , that would cause the engine to ping. If this is the case then put in a cooler range plug (IMG:style_emoticons/default/thumbsup.gif)

My friend suggested I try higher octane and see if that solves it. I forgot to do that with my last gas up, but I'll give it a try.



I got whatever Autozone had for spark plugs. The tech suggested I just get the cheaper ones since they were lower power and the higher power current ones might not work as well (such as the platinum brands).
The engine seems to ping more after it has warmed up a bit.

??? I've just replaced my Bosch IR plugs with a set of E3's to see if there is a difference. You sure this is the problem?

This might help http://en.wikipedia.org/wiki/Octane_rating

First off, the car is designed for 87 octane. So accordingly it should be able to use 87 without pinging and using anything more is just masking a bigger issue.

If you have replaced the spark plugs recently and the sound came after that, I would definately start there. Just because some autozone **** told you which plug to buy, doesn't mean he has any idea of what he is talking about. If the plug heat range is indeed too high, as described above, it could very well contribute to detonation within the combustion chamber.

If it hasn't just started you need to start looking into why either the engine is running too lean, or why the spark timing is off. Two things I would do is replace the fuel filter, and then reset the computers keep alive memory by disconnecting the negative battery cable on the car for about 10-15 minutes. It'll let the computer re-learn its long and short term fuel trims and perhaps solve the problem for a little while, or until it re-learns its bad habits from an underlying problem.

True, using a higher octane will only be a band aid, and a waste of money.

You must have more knowledgeable autozone ****'s than I do. (IMG:style_emoticons/default/grin.gif) They only know what the computer tells them. I understood it that he bought a regular copper plug instead of an OEM/better.

And why would you replace the fuel filter? Wouldn't that cause a low fuel pressure problem that would throw a CEL?

I was just wondering (IMG:style_emoticons/default/thumbsup.gif)

This post has been edited by rsquared: Nov 5 2009, 12:26 AM

If the fuel filter is extremely plugged, it can cause a fuel restriction. The PCM is able to adjust for this by adding time to the injectors pulse width but it can only adjust so far. In an extreme case, the PCM may have adjusted as far as it can and the motor may then start running a bit lean and pinging. A general rule of thumb is to replace the fuel filter every 30000-45000 miles. Typically depends on manufacturer but its a good rule anyway.

Keep in mind though this is all speculation. Without actually being there to diagnose things first all we are doing is throwing parts at it till the problem goes away. There are a couple of basic tests you can do to help narrow the problem down to a specific area.

Ignition tests such as a power balance test are useful. With the engine idling, pull one spark plug wire out at a time. Pull it out far enough that the voltage in the wire won't arc to the spark plug; in esscence you are eliminating the input of one spark plug while the car is running. If that cylinder, and spark plug are contributing well to the overall power of the engine, you will hear the engine bog down a lot and run very rough. Record how many RPM's the engine drops and record it. Do this to all four cylinders and record the RPM drop. The cylinder that records the least RPM drop is the cylinder that isn't contributing as much as the others. This could be due to low cylinder compression or weak spark going to that cylinder. The same test can be performed with the fuel injectors to locate a possible injector problem.

Fuel tests can be as simple as getting a fuel pressure tester and hooking it up to the system somewhere post-pump. Typically there is a schrader valve close to the fuel rail that can be tapped into for this. Record the pressure and compare it to a spec that the factory gives. If it is too low, chances are it can be a plugged fuel filter or a malfunctioning pressure regulator. If the pressure regulator is vacuum operated, check the vacuum hose going to it first to make sure there are no vacuum leaks (which could also cause a lean condition and stumbling) and then make sure the membrane inside the regulator is intact.

There are so many tests that can be performed to narrow things down. I hate telling people what the problem is without actually testing things first.

Ok, here's an update:

Ping has gotten worse in last few days. I am now hearing it 2nd and 3rd gear where it usually was in 4th and 5th only. When the engine is cold, there is no ping. It takes about 2-3 minutes of engine running before I start to hear the ping.

Here's what I just did recently:

1. Changed out spark plugs (had the basic coppers before) to the Bosch Platinums (cheap fix attempt). The ping is still there, but less frequent.
2. Threw some injector cleaner stuff in and topped off half a tank with 93 octane. Drove around for a bit being very gentle with the gas pedal and noticed the pinging go away after 3-4 miles. I drove a bit longer and put more stress on the engine and it wouldn't ping at all.

This morning I'm changing the fuel filter (haha it's under the rear seat, who woulda thunk it!). At some point I'll go back to 87 octane (i'll empty the tank and put in a half gallon of 87 octane to see if it still pings).

I haven't been able to hook up anything to diagnose what the exact cause is, just doing some quick fixes that it probably needs anyways.

This post has been edited by moogulguy: Nov 8 2009, 10:37 AM

Hi, I am new member here and this is my first post.

I have upgrade my engine by porting polishing,oversize piston so it has higher compression and it very recommend to use gas with minimum octane 92. When I use 88 octane, I have some problem with you (engine detonation), so this is what I have doing to avoid engine detonation.

1. I change my spark plug to autolite platinum and I add sparkplug ring (now 2 layer, before 1 layer). It will put down engine compression and may be decrease your power too.

2. clean my intake valve with injector cleaner (better use foam type) and reset my ecu.

3. set my rpm stationary to 1000 rpm to avoid engine lag between gears.

4. change my air intake with stainless type and wrap it with heat shield to increase cold air capacity.

Until now I don't feel engine detonation again unless if I want to take it to race. And issues that engine power will decrease, I don't feel it yet, but I feel my torque increase. It prove when I drive on hill, usually I use 3 gear and 3000 rpm, now 3 gear and 1500 - 2000 rpm. Beside that I can reach 175 km/h with using 4500 rpm on final gear

If your engine still detonate, may be you should check your head and set again your cam.

^^^Not sure why you are spacing your spark plugs up with two gaskets... Moving the spark plug up in the combustion chamber will have next to no effect on the compression of the motor. And I can't imagine the compression of your motor being such that the piston would risk hitting the spark plug at TDC with the head being of a pent-roof design. And if the car lags between shifts, there is something else wrong. The car shouldn't be letting the RPM's drop so quickly that you need to do this. Its an emissions thing. And I seriously doubt that insulating your intake tubing would do much for performance. As soon as the air gets into the hot intake manifold, its gonna heat right up.

To the OP, glad its doing better. I hope the problem is gone for good. Let us know how it acts when you put in the regular gas again.

Welcome. Now start a new thread and stop hijacking mine! (IMG:style_emoticons/default/evil.gif) (I'm kidding)



I was hearing a little bit of ping when I would push the engine to over 3000 rpm yesterday right after the fuel filter change (I"m guessing since I don't have a tachometer). But I forgot to pull the battery cable off the negative terminal for 15 min till today, so I"ll evaluate it for the rest of the week. I have a half a tank to go till the 87 octane test.

Try an octane booster additive. As small as the tank is, it should take care of the problem if it's pre-detonation.

I have a '02 with an auto tranny and I have a tach. Why don't you?

I'd rather have an oil pressure gauge.

This post has been edited by rsquared: Nov 9 2009, 10:49 PM

I did put in 93 octane. But I'd like to be able to run 87 octane since the car was made to work with that. Trying to sort out what exactly is causing the detonation (spark knock).

I dunno why they didn't include a tach. It would have been nice, but this particular model didn't have one.

Moogulguy, hows the car running? Any improvement with the fuel filter replacement?

Still at just under half a tank. THIS CAR MAKES IT HARD TO GET THROUGH A TANK. Crazy fuel efficiency.

I gun the engine rpm's up in 4th and 5th gear once in a while to see how it handles that, and I occasionally hear a ping, but it's rare right now.

I don't have enough time to go for a trip, but maybe I can this weekend.

well keeping the testosterone in check, let's keep this simple and not to technical. If your car pings and it's all stock and you have no CEL lights then simply up your octane. I don't care what a manufacturer says about 87 octane. It is no good for any car as it varies in quality. This is the first thing you need to do and being that it only does it when cold only means your car is in open loop, running richer, and with different timing. So for those that suggested upping the octane I give you a (IMG:style_emoticons/default/trophy.gif) . But then who am I to say your right?
Anyways aside from this, running standalone ecu's like AEM, Motronics, MS, and what not is not a good fix for someone who is just trying to get a A-B car running so please don't suggest this as a fix. I have it on a weekend racer and that's it, I would never recommend it on a daily driver as it is not practical, efficient or reliable. Not everyone here has built a Accent engine and I would never dream of doing it. Would much rather just boost it till it blew up then put another one in (IMG:style_emoticons/default/grin.gif) . Just not worth my money as it's only as good as the tune you have. Besides who's to say those little 14" tires, toothpick axles and basic 5spd internals are gonna handle anything over 200-300 hp?
Oh and my belief on spark plugs is if the car calls for platinum then put them in, of not then get the cheapest $1 plugs you can find but dont get Bosch supers, or any bosch for that matter when dealing with Hyundais. Good rule of thumb.
Just to add i'm running plugs from my Probe on my Accent because it's what I had at the time, no pinging and get 35mpg at 80mph. I have no idea what heat range they are nor do I care.


My .02 cents.

This post has been edited by mac1: Nov 11 2009, 11:41 PM

Update 11-22-09:

At first I could still hear an occasional ping when I would put the engine under duress (no where close to red-lining it) while running the higher octane fuel.

Here's what I did last week:

1. Changed the oil (it had been 3200 miles since my last change). The old oil was really thin and blacker than I'd expect it to be, the garage I took it to previously used a synthetic blended oil. I replaced it with Quaker State 5w-30 with no synthetic additives this time.
2. (No idea if this is related) I still had a slow oil leak from the valve cover gasket, so I added a small amount of high temp silicone sealant, making sure it wouldn't get into the engine, and reapplied the gasket in the correct manner.
3. I tried 2 gallons of Shell 87 octane (waited to do this after nearly emptying the tank). Things ran well with no noticeable pings.
4. I recently put in 3 gallons of 87 octane from another gas station that I frequent (again after I had run my other fuel close to empty). Things are really running good with the engine. I gave the engine a work out for 20 miles of variable driving and no pings.

(note: It was odd to me that the oil change seemed to improve the ping issue. I was still running octane 93 and very occasionally hearing a ping, but after the oil change, everything seemed to be running smoother and the pings even less frequent.)

So final outcome: no pings. I'm happy.

Thanks again for the helpful feedback guys.

This post has been edited by moogulguy: Nov 22 2009, 01:41 AM