Help Please

[2000co]

Hello,

I have 2000 Explorer XLT V6 SOHC. 3k miles ago I replaced my sparkplugs (Bosch double platinum), & sparkplugs wires (Autolite Professional). The engine was not working smooth on idling after that but I decide to drive it for a few more days. A week later I change the oil (5-30W Valvoline Syn Blend) and notice a knocking noise from the engine. I decided to replace the sparkplugs to Autolite Double Platinum and after I replaced the plugs the noise stopped and the engine was idling smooth (as smooth as you can get from this engine).

Last weekend I replaced the oil (5-30W Max Life Syn Blend) and the knocking noise return after the oil change. The engine makes this knocking noise when it’s idling. When you start the engine it work fine with no noise but when it start to lower the RPM the knocking starts and it idle rough and it also missing.

Dose anyone know what’s wrong with this engine? Help please

 

[Exploderpilot]

this is just a shot in the dark, but the later models are largely computer controlled in order to maximize gas mileage and what not. when you changed plugs and wires it probablt gave you a hotter spark, and a different combustion profile. if you do a search on this site, you should be able to find a thread about resetting the ECU. it has something to do with disconnecting the battery for a certain amount of time. then it will take your engine a while to "re-learn" the new situation, and it should smooth out.

 

[mawrazen]

When I changed my plugs and wires, I accidentaly knocked off a vacuum line. Check for a loose or disconnected line.

 

[2000co]

i will try the ECU reset. i checked the vacuum lines and it's all good. thanks

 

[2000co]

Resetting the ECU didn’t help. I notice when you start the engine it’s not making the noise but once the engine warm-ups and you let it idle for 30 second then it’s start knocking and missing.

Could it be a sensor?