dahbears27
New Member
- Thread starter
- #1
Hi all.
First time poster and Gladiator owner. I want to start off saying I really enjoy my 2020 Gladiator Rubicon 3.6l, but a rough idle has been driving me crazy. I bought the truck used at the 52,000ish mile mark beginning of this year. I don't think I noticed the rough idle during purchase. Current mileage is about 64,000. The rough idle is intermittent but occurs and is most notable in most starts from cold and some of warm starts. I have a Tazer installed (by me) to bypass the security module, and subsequently auto start/stop, to allow me some more diagnostic freedom.
Generally here is the symptom flow and extra details:
The start is smooth, no excessive ticking or noise as the oil pressure comes up. No unusual ticking even while the rough idle is occurring. I am currently running 0W-30 Amsoil SS. 0W-20 Amsoil Extended Life on the previous change as soon as I returned from the dealer. As the idle RPM comes down it's still smooth even around the 750-850 mark. But as the idle drops down to its lowest, 650-675 I believe, a deep rumble/vibration can be felt and heard. It comes in short waves/surging. Smooth then rough back to smooth etc. Thankfully, the sensation has NOT changed e.g gotten worse. I want to check all I can before God forbid I have to divert to a dealer.
Here are the things I have checked so far. I would love some more suggestions:
- Fuel: I normally run 87 octane however I have been testing a couple tanks of 91. I cannot notice a difference so far. I also have used multiple stations to rule out fuel contamination.
-Ambient Temperature: I really noticed the rough idle at first in February. Its July in NE and the idle is still odd. So even with summer fuel and warmer ambient temps there isn't a difference.
-Fuel Economy: Compared to when I bought the truck and now I actually have gotten better mileage, likely summer vs winter blend, However I track all fill-ups manually and have seen no discernable change or degradation.
-Misfires: Some other threads about rough idle and the classic Pentastar cam failures indicate that higher than normal misfires on the passenger side cylinder bank can indicate issues. Using JScan after my 30 minute commutes, multiple times, has resulted in readings of less than 10 misfires on any one cylinder during the drive. My drive includes a few stop lights and spirited accelerations to get up to speed for the interstate.
-Throttle Body: I disassembled and cleaned the butterfly during my last oil change. Even though it had some oil deposits it wasn't filthy.
-Codes: I have had no engine or related codes while I have owned the vehicle. I've also checked for stored codes and none are present.
-Oil filter: I cut apart the last filter and checked for metal and was able to spot no noticeable flakes or debris under good lighting.
I hope these details can give someone with more experience with this issue some idea of other things to check. I've had far too many dealers burn me so I'm definitely "dealer adverse"
I have access to AlphaOBD and JScan. Any ideas are much appreciated.
Thanks!
First time poster and Gladiator owner. I want to start off saying I really enjoy my 2020 Gladiator Rubicon 3.6l, but a rough idle has been driving me crazy. I bought the truck used at the 52,000ish mile mark beginning of this year. I don't think I noticed the rough idle during purchase. Current mileage is about 64,000. The rough idle is intermittent but occurs and is most notable in most starts from cold and some of warm starts. I have a Tazer installed (by me) to bypass the security module, and subsequently auto start/stop, to allow me some more diagnostic freedom.
Generally here is the symptom flow and extra details:
The start is smooth, no excessive ticking or noise as the oil pressure comes up. No unusual ticking even while the rough idle is occurring. I am currently running 0W-30 Amsoil SS. 0W-20 Amsoil Extended Life on the previous change as soon as I returned from the dealer. As the idle RPM comes down it's still smooth even around the 750-850 mark. But as the idle drops down to its lowest, 650-675 I believe, a deep rumble/vibration can be felt and heard. It comes in short waves/surging. Smooth then rough back to smooth etc. Thankfully, the sensation has NOT changed e.g gotten worse. I want to check all I can before God forbid I have to divert to a dealer.
Here are the things I have checked so far. I would love some more suggestions:
- Fuel: I normally run 87 octane however I have been testing a couple tanks of 91. I cannot notice a difference so far. I also have used multiple stations to rule out fuel contamination.
-Ambient Temperature: I really noticed the rough idle at first in February. Its July in NE and the idle is still odd. So even with summer fuel and warmer ambient temps there isn't a difference.
-Fuel Economy: Compared to when I bought the truck and now I actually have gotten better mileage, likely summer vs winter blend, However I track all fill-ups manually and have seen no discernable change or degradation.
-Misfires: Some other threads about rough idle and the classic Pentastar cam failures indicate that higher than normal misfires on the passenger side cylinder bank can indicate issues. Using JScan after my 30 minute commutes, multiple times, has resulted in readings of less than 10 misfires on any one cylinder during the drive. My drive includes a few stop lights and spirited accelerations to get up to speed for the interstate.
-Throttle Body: I disassembled and cleaned the butterfly during my last oil change. Even though it had some oil deposits it wasn't filthy.
-Codes: I have had no engine or related codes while I have owned the vehicle. I've also checked for stored codes and none are present.
-Oil filter: I cut apart the last filter and checked for metal and was able to spot no noticeable flakes or debris under good lighting.
I hope these details can give someone with more experience with this issue some idea of other things to check. I've had far too many dealers burn me so I'm definitely "dealer adverse"
I have access to AlphaOBD and JScan. Any ideas are much appreciated.Thanks!
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