'03 optima Pinging under low rpm load

sportster64 · 08-09-2006, 05:52 PM

Have a 2003 optima with the 2.4L manual tranny. When you get the rpm's down low and it is under a load - it pings reallly bad . I thought it might be somewhat normal - but I just drove a 2004 optima 2.4l manual tranny - and it doesn't ping under the same loading conditions.
Any ideas ??

TwinTurbo · 08-09-2006, 07:13 PM

That could be a few different things I would try to put some dry gas in and get gas a different place. Could also try some fuel injection cleaner do the easy stuff first if you have not done that yet.

Classic boy · 08-11-2006, 03:51 AM

Get a scanner and check the codes, the engine has a knock sensor that should prevent pinging, either the sensor is bad, or the engine management system is ignoring it for some reason. Either way there should be a code set.

TwinTurbo · 08-11-2006, 07:41 AM

The check engine light will be on if there is a code. The knock sensor is just that a knock sensor, it only senses a certain frequency. But yes it could be bad. Before you pay some to check it out do some simple things to see if that helps. Could be water in the fuel,could be carbon in the combustion chamber, like I said before it maybe a number of things.

Classic boy · 08-12-2006, 01:29 AM

Quote:

Originally Posted by TwinTurbo

The check engine light will be on if there is a code. The knock sensor is just that a knock sensor, it only senses a certain frequency. But yes it could be bad. Before you pay some to check it out do some simple things to see if that helps. Could be water in the fuel,could be carbon in the combustion chamber, like I said before it maybe a number of things.

The knock sensor does a little more than detect knock for the sake of detecting knock.
The engine management system uses that info to trim the ignition timing curves in its program to stop the knock, it will continue to retard timing to stop the condition.
So if it is knocking (which is another term for pinging) the engine management is not doing its job correctly, because modern cars with a knock sensor should never ping.
BTW you can have codes without the engine light being on. NOT every code will bring on the lamp only a certain class of codes as determined by the maker will bring on the lamp.

TwinTurbo · 08-12-2006, 08:59 AM

I could have gone into a long drown out explanation on how the sensor works but I did not just a brief one on how it sense knock. Well my 01 kia pings so does my 95 ram and my 01 tracker, so I guess all my knock sensors are bad. Yes you are right about there being codes set and the light not being on but when the computer sees a problem the light will come on it may or may not go out when you turn the key off. I know on dodge trucks thy had pinging on some years and they had to re flash the computer ( known as death flash )where they would retard the timing to get rid of of it, the knock sensor was working but it did not see it. We could go back and forth to try and prove each other wrong, All I was doing was telling that person to try a couple of things to see if that would work. I did not want to them going to the dealer and paying the 30 to 50 dollars and have them say you have water in you tank.

Classic boy · 08-14-2006, 12:40 AM

I think if the knock sensor will not tame pinging then it must not have enough control authority to retard the ignition enough to prevent knocking.

Sounds like a fuel quality issue if the engine managment system cannot bring detonation under control if the knock sensor is fully serviceable.

The first step is to confirm whether it is functioning, a simple roadside test is to have an assistant hold the engine revs at 1500rpm in park, and then tap the knock sensor a couple of time with the plastic handle of a screwdriver, if the speed decays whilst the sensor is being tapped and recovers when the tapping stops then you know the engine managment is trying to compensate for the detected knock.