Valve Noise Mirage 2001, there is a valve noise in a 4g93 mirage engine Options

[mirlomanzo]

hi friends,

I need some help with my mirage 2001,

when it starts the OBDII indicates a TIMING about 5 degres, but when in push the acelerator pedal it increse abrupt at 65 degres and a valve sound apears, it is more obvious in a uphill,

the OBDII don't reports any error codes, i understand that the ECU advance the time engine to obtain more power and the knok sensor controls the noise, but I can't find the KNOCK sensor,


any sugestions are wellcome...

thanks....

[KiT TeUnG 2549]

This engine does not have a knock sensor , it uses the ignition coils to referance on knock, by the low voltage impendance signals of each cylinder, this is how they also can tell specific cylinder misfire.

the ignition timing sequince is not just to "gain power" but its for using when yu have extremely pow octane petrol , when the octane is low it is prone to pre detonation before firing sequince and engine knock. This is the main reason why the PCM regulates ignition timing and also fuel spray to even out this ,knock retard and predetination.

If yu have had yur timing belt replaced before make sure that the timing marks are not too far advanced over the standard timing marks. Other than that yu may be using petrol with extremely low octane.

[mirlomanzo]

thankyou "KiT TeUnG" for the answer,

you realy clear some wrong ideas that I have...


in logic order to resolve my problem, you opinion is....

1. try 98 octanes fuell(in this country the comon is 95 octanes)
2. change the timing belt...
3. change the ignition coil(2 of them)

it is the right order?

I realy apreciate your help and thanks...

[KiT TeUnG 2549]

Well i would try using better octane petrol , or changing the place that yu usually fill up or pump on petrol. ALso yu can try an octane additive. If the engine has above 106,000 km (or above 66,000 miles) the timing belt should be replaced anyway.

But the reason for the knocking seems inherant to engine load. As when yu are going up hill there is more load on the engine , it will need to spray more fuel , wut seems to be happening is that the octane is too , when the injectors is spraying more fuel to help yu accelerate up the hill/ incline the poor octane causes predetination as it hits the hot cylinder walls . This is called "pre-detination" or knock retard . In these situations the PCM simulates the ignition firing in a variance of negative mainly ignition firing to try and reduce knock retard that is being caused.

Sometimes , an aged timing belt and poor octane petrol will both cause this combined issue.

[mirlomanzo]

ok,

I understand,


thanks again, as soon as posible I will try your recomendations,

and I will send you some feedback...

thanks a lot and thanks to this mitsubishi forum, it is great....

[KiT TeUnG 2549]

I hope it gets sorted out

[pro-driver22]

check ur rod bearing