help with detonation

[ooraceredgt]

i let my dad drive my car yesterday and he overevved it for about 3 seconds before he realized it and ever since then the car has been detonating under full throttle. ive tried retarding the spark and leaning out the fuel but it doesnt seem to really help. is my car screwed? ive also noticed a slight miss throughout the rpm range. when the valves rattle its running rich right? i wanna make sure im trying to fix the problem and not worsen it. it still hauls butt...but i dont wanna take anymore chances. please help me

 

[8yourZ06]

This is a total guess but Im wondering if you have a valve thats not closing all the way? I wouldnt think a couple seconds of overreving would have floated a valve but I guess anythings possible. Maybe pull the valve covers off and inspect the valvetrain.

 

[AdRock]

i let my dad drive my car yesterday and he overevved it for about 3 seconds before he realized it and ever since then the car has been detonating under full throttle. ive tried retarding the spark and leaning out the fuel but it doesnt seem to really help. is my car screwed? ive also noticed a slight miss throughout the rpm range. when the valves rattle its running rich right? i wanna make sure im trying to fix the problem and not worsen it. it still hauls butt...but i dont wanna take anymore chances. please help me

Retarding the timing was one correct way to stop the pinging. However leaning out the fuel ratio is NOT. Running too lean will cause detonation. If you were to retard the timing and richen the A/F ratio it should stop pinging unless there is something fairly major that's wrong.

The rattle you here is not coming from the valves. It's coming from the pistons banging around inside the cylinders because of the insane forces being put on them when it pings, and as I said above causing the engine to run too lean will cause detonation.

 

[CanadaStang]

Retarding the timing was one correct way to stop the pinging. However leaning out the fuel ratio is NOT. Running too lean will cause detonation. If you were to retard the timing and richen the A/F ratio it should stop pinging unless there is something fairly major that's wrong.

The rattle you here is not coming from the valves. It's coming from the pistons banging around inside the cylinders because of the insane forces being put on them when it pings, and as I said above causing the engine to run too lean will cause detonation.

Yup, lean = detonation