Need help with knock sensor issue

[crockett]

2 month ago I faced a check engine light and pulled the code P0330, generated when a (intermittent) malfunction is detected in the knock sensor 2 circuit that causes it to not operate properly.

So I replaced both knock sensors on the Pentastar. 4 weeks later, the same code back.

I just hooked up a scanner and polled the sensor voltage for both.

When the engine is cold, both have pretty comparable voltages and voltage ranges, see the first section in the first screenshot.

After about 2 minutes, the 2nd sensor dropped in voltage range for maybe 20 seconds or so.

After being in the normal range for a while, it dropped again and stayed in the lower range ever since. The voltage is basically cut in half on sensor 2.

I wiggled the plug in the sensor, it was fully seated.

Wiggling the plug, the cable, the attached harness and the first large connector right next to the engine, while it was running, didn't change the voltage, range or function at all. So this doesn't look like a broken wire or a bad connection.

I took a wrench and hammer to the right side of the engine block, standing in-front of it, close to the 2nd sensor, and wacked it pretty good. Both sensors reacted, see the 2nd screenshot.

My conclusion so far is:

- The intermittent drop in voltage range on the 2nd sensor goes along with the error code, also claiming it to be intermittent.
- The drop seems to be related to the engine temperature.
- Since I replaced the sensors 2 months ago, I'm having a hard time believing that I'm dealing with a defective sensor yet again.
- The drop is sudden and wiggling on the cables and connectors had no impact, hence I assume that the computer causes the sudden change in the reading of the voltage.

1.) What cold be at play?

2.) What should I test / do next?

 

[Wild one]

2 month ago I faced a check engine light and pulled the code P0330, generated when a (intermittent) malfunction is detected in the knock sensor 2 circuit that causes it to not operate properly.

So I replaced both knock sensors on the Pentastar. 4 weeks later, the same code back.

I just hooked up a scanner and polled the sensor voltage for both.

When the engine is cold, both have pretty comparable voltages and voltage ranges, see the first section in the first screenshot.

After about 2 minutes, the 2nd sensor dropped in voltage range for maybe 20 seconds or so.

After being in the normal range for a while, it dropped again and stayed in the lower range ever since. The voltage is basically cut in half on sensor 2.

I wiggled the plug in the sensor, it was fully seated.

Wiggling the plug, the cable, the attached harness and the first large connector right next to the engine, while it was running, didn't change the voltage, range or function at all. So this doesn't look like a broken wire or a bad connection.

I took a wrench and hammer to the right side of the engine block, standing in-front of it, close to the 2nd sensor, and wacked it pretty good. Both sensors reacted, see the 2nd screenshot.

My conclusion so far is:

- The intermittent drop in voltage range on the 2nd sensor goes along with the error code, also claiming it to be intermittent.
- The drop seems to be related to the engine temperature.
- Since I replaced the sensors 2 months ago, I'm having a hard time believing that I'm dealing with a defective sensor yet again.
- The drop is sudden and wiggling on the cables and connectors had no impact, hence I assume that the computer causes the sudden change in the reading of the voltage.

1.) What cold be at play?

2.) What should I test / do next?

Swap sensors side to side and see what happens. Are they OEM sensors?

 

[crockett]

Swap sensors side to side and see what happens. Are they OEM sensors?

I'm trying to remember where I bought the 2 sensors and I'm 90% sure they are Duralast Ignition Knock (Detonation) Sensor SU3333 from AutoZone. The other option would be Carquest Premium Knock Sensor EKC1012 from Advance Auto Parts. The Duralast sensor has a rating of 4.9 out of 5.

Do you think that a Mopar part would have been any better? The OEM Knock Sensor - Mopar (5149188AA) costs 3 times as much.

Swapping sensors will be a huge pain in the ass because I would have to pull the upper and lower intake, as well as the oil cooler, at least 2 times and put everything back together for testing.

 

[Wild one]

I'm trying to remember where I bought the 2 sensors and I'm 90% sure they are Duralast Ignition Knock (Detonation) Sensor SU3333 from AutoZone. The other option would be Carquest Premium Knock Sensor EKC1012 from Advance Auto Parts. The Duralast sensor has a rating of 4.9 out of 5.

Do you think that a Mopar part would have been any better? The OEM Knock Sensor - Mopar (5149188AA) costs 3 times as much.

Swapping sensors will be a huge pain in the ass because I would have to pull the upper and lower intake, as well as the oil cooler, at least 2 times and put everything back together for testing.

Supposedly the trucks don't like after market sensors.To me it sounds like one sensor is a bit subpar,and to check if it is ,would be to swap them side to side.

 

[crockett]

Supposedly the trucks don't like after market sensors.To me it sounds like one sensor is a bit subpar,and to check if it is ,would be to swap them side to side.

In that case I'm inclined to buy 2 new sensors, Mopar this time, pull the intake and the oil cooler, test the wires, and if I can't find any issue with the wires, replace both sensors for good measure. Having to dig into this another 2 times would really **** me off. The lower intake already has 2 stripped threads that I semi fixed with epoxy. Chances are that this crap will require a new lower intake as well. God do I hate all these plastic parts mounted to an engine!

 

[Wild one]

In that case I'm inclined to buy 2 new sensors, Mopar this time, pull the intake and the oil cooler, test the wires, and if I can't find any issue with the wires, replace both sensors for good measure. Having to dig into this another 2 times would really **** me off. The lower intake already has 2 stripped threads that I semi fixed with epoxy. Chances are that this crap will require a new lower intake as well. God do I hate all these plastic parts mounted to an engine!

I know nothing about the 3.6,but i have fixed stripped throttle body bolts on the 5.7's composite intake manifold,by making studs.Don't know if you could jury rig a stud fix or not on the 3.6 though.

 

[crockett]

I know nothing about the 3.6,but i have fixed stripped throttle body bolts on the 5.7's composite intake manifold,by making studs.Don't know if you could jury rig a stud fix or not on the 3.6 though.

Sweet idea, I will do that! Did you just glue those studs into the plastic or did you put some countersunk nut on the other side.

 

[Wild one]

Sweet idea, I will do that! Did you just glue those studs into the plastic or did you put some countersunk nut on the other side.

I ran a 1/4" tap in the holes and threaded the studs in,lol. Used 1/4" threaded rod/ready rod to make the studs,whether you could use a 1/4" stud i don't know though,as the 5.7's throttle body screw holes will accept a 1/4" tap and stud with-out drilling the holes out. I didn't glue them in,as the studs grabbed pretty good after running a tap into the plastic,but if you're a bit suspicious on them holding you could glue them in

 

[crockett]

I ran a 1/4" tap in the holes and threaded the studs in,lol. Used 1/4" threaded rod/ready rod to make the studs,whether you could use a 1/4" stud i don't know though,as the 5.7's throttle body screw holes will accept a 1/4" tap and stud with-out drilling the holes out. I didn't glue them in,as the studs grabbed pretty good after running a tap into the plastic,but if you're a bit suspicious on them holding you could glue them in

I'm already using larger screws so I will have to use a larger rod, maybe something metric, thread AND glue it in, and drill out the upper intake a little to match the larger stud.

 

[Wild one]

I'm already using larger screws so I will have to use a larger rod, maybe something metric, thread AND glue it in, and drill out the upper intake a little to match the larger stud.

If you want it semi-permanent use JB Weld,but i'd see how whatever you come up with threads in first before gluing it in place.The majority of threaded screws into plastic on a Mopar are 3/16'"or smaller so a 1/4" stud is already a step up in size

 

[pacofortacos]

Check for a bare wire touching ground intermittently, just fixed my son's Jeep that was having the same issue (but an older 4.7 HO engine). His was a very small spot that rubbed on the block in the back and intermittently would touch.

Can you check the voltage at the plug when it is acting up?

 

[crockett]

Check for a bare wire touching ground intermittently, just fixed my son's Jeep that was having the same issue (but an older 4.7 HO engine). His was a very small spot that rubbed on the block in the back and intermittently would touch.

Can you check the voltage at the plug when it is acting up?

I'll try that tomorrow, I should be able to get into the back of the plug with some flexible back probes. Good idea to compare that vs the read-out on the scanner!

 

[crockett]

Just for the record, this issue was on my Caravan with a Pentastar. I just wrote here since it was related to the same engine.

I bought a new harness for the knock and temp sensors. Talked to a nice tech at a dealer today, he said that the harness gets messed up most times when oil and coolant in the valley soaks the wires and connectors for a while, and that was the case in my van since this POS plastic oil cooler housing leaked for God knows how long.

That harness is on backorder, NATIONWIDE, with no ETA, because so many Caravans and other vehicles with the Pentastar are dealing with the same chain of shtt.

I called around for 2 hours and found one dealer 1 hour up North, who had 1 harness left in stock.

Just replaced both knock sensors, the harness, power steering cooling line, power steering fluid and coolant today. Checked the connecting harness for wire issues but didn't find anything. Removed the cheap ass tape and replaced it with proper German made Tesa's High Heat Harness Tape.

Did a short test ride to make sure its still running.

Will drive it around for a week and see if the codes go away and if the power steering fluid stops dripping.

If any of this shtt comes back one more time, I won't further mess with it, just drive this POS in the ground. I'll call my local Toyota dealer on Friday and put money down on a new Sienna at MSRP. By the time it rolls off the line, this Dodge should be good to go... to the junkyard.

These Caravans are a joke. Plastic everything, nothing was designed to last. You pull things apart to fix problems and all kinds of plastic taps and parts fall apart by just looking at them. I used to work for Benz back in the mid 90s. Man did we enter devolution ever since!

 

[Wild one]

Just for the record, this issue was on my Caravan with a Pentastar. I just wrote here since it was related to the same engine.

I bought a new harness for the knock and temp sensors. Talked to a nice tech at a dealer today, he said that the harness gets messed up most times when oil and coolant in the valley soaks the wires and connectors for a while, and that was the case in my van since this POS plastic oil cooler housing leaked for God knows how long.

That harness is on backorder, NATIONWIDE, with no ETA, because so many Caravans and other vehicles with the Pentastar are dealing with the same chain of shtt.

I called around for 2 hours and found one dealer 1 hour up North, who had 1 harness left in stock.

Just replaced both knock sensors, the harness, power steering cooling line, power steering fluid and coolant today. Checked the connecting harness for wire issues but didn't find anything. Removed the cheap ass tape and replaced it with proper German made Tesa's High Heat Harness Tape.

Did a short test ride to make sure its still running.

Will drive it around for a week and see if the codes go away and if the power steering fluid stops dripping.

If any of this shtt comes back one more time, I won't further mess with it, just drive this POS in the ground. I'll call my local Toyota dealer on Friday and put money down on a new Sienna at MSRP. By the time it rolls off the line, this Dodge should be good to go... to the junkyard.

These Caravans are a joke. Plastic everything, nothing was designed to last. You pull things apart to fix problems and all kinds of plastic taps and parts fall apart by just looking at them. I used to work for Benz back in the mid 90s. Man did we enter devolution ever since!

Tell us how you really feel, Hopefully you got it sorted out though

 

[crockett]

Tell us how you really feel, Hopefully you got it sorted out though

I bought this minivan as a beach beater for 3 grand and turned it into a camper, so that I can hang at the beach the entire day or even for a long weekend, and don't have to worry about any of my nice cars getting banged up by ignorant beach goers and their beach gear. Now I have to worry about being stranded, not much better. In the end I should have bough a new Sienna right away.

My pet also wants to drive this thing into the bay...















We are both a little bitter at times. Heck we even grow the same hair color