I’m working on a 2017 Kia Sorento 3.3 that has a spark knock when in Drive at idle, and it also dies at idle. We had a P0506 code, so we replaced the throttle body, throttle pedal, and Bank 1 catalytic converter. Did the relearn procedure for the throttle body, but after a test drive, the car died again when we got back, and no new codes appeared. Anyone know what could be causing this?
Since there’s a spark knock but no knock sensor codes, it could be something off with the timing or fuel mixture. Have you checked if the timing is advancing when in gear?
CAROL said:
Since there’s a spark knock but no knock sensor codes, it could be something off with the timing or fuel mixture. Have you checked if the timing is advancing when in gear?
I haven’t had a chance to check that yet, but I will as soon as I can. Thanks for the suggestion.
If the relearn procedure didn’t help, it might be worth double-checking the throttle body calibration. Sometimes they need a few cycles to really settle in.
TomHenry said:
If the relearn procedure didn’t help, it might be worth double-checking the throttle body calibration. Sometimes they need a few cycles to really settle in.
Good point. I’ll give it another shot to see if it helps.
It’s strange that there’s no noise from the HPFP but you’re still getting those readings. Maybe the issue is in the fuel system somewhere else. Did you check the fuel pressure in gear?
MythicalMerlin said:
It’s strange that there’s no noise from the HPFP but you’re still getting those readings. Maybe the issue is in the fuel system somewhere else. Did you check the fuel pressure in gear?
Yeah, I did. It’s around 1300 PSI in gear at idle, and 800-900 in neutral. Does that sound normal?
MythicalMerlin said:
It’s strange that there’s no noise from the HPFP but you’re still getting those readings. Maybe the issue is in the fuel system somewhere else. Did you check the fuel pressure in gear?
Those numbers don’t seem too far off, but it might still be worth monitoring to see if there are any sudden drops or spikes. Fuel pressure inconsistencies can cause knocking.
Could be a fuel delivery issue causing a lean condition, which might explain the spark knock. Have you checked the injector pulses when the knock occurs?
Murphy said:
Could be a fuel delivery issue causing a lean condition, which might explain the spark knock. Have you checked the injector pulses when the knock occurs?
Yeah, in neutral at idle the injector fire pulse is around 0.7-0.8, but in gear it jumps to 3.3. Not sure what that means though.
Murphy said:
Could be a fuel delivery issue causing a lean condition, which might explain the spark knock. Have you checked the injector pulses when the knock occurs?
That jump is pretty significant. Might be worth looking into why there’s such a change between neutral and drive. Could be a sign of something upstream causing the engine to adjust heavily.
If the fuel and timing all check out, you might want to look into the EGR system or any vacuum leaks. Sometimes an unnoticed air leak can cause issues at idle, especially under load.
Cruise said:
If the fuel and timing all check out, you might want to look into the EGR system or any vacuum leaks. Sometimes an unnoticed air leak can cause issues at idle, especially under load.
I’ll have my techs take a look at that. Could be something we overlooked. Thanks for the heads-up.