Great deals on JK parts on Amazon!

Looking for parts for your Jeep Wrangler JK? Checkout the selection of JK parts Amazon has to offer, many with 2-day Prime shipping!

Click the image below to browse JK parts on Amazon.

Jeep Wrangler JK Parts on Amazon

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.

Pentastar Misfire on Cylinders 1, 3, & 5


Rdartua

Member
Joined
Nov 29, 2021
Messages
39
Location
06831
Actually so far they determined that its not Heads, Spark plugs, wires or coils....Which I determined before. But they capped diagnostics at 500, so at least that
 

Threepointsix

JK Enthusiast
Joined
Dec 11, 2020
Messages
235
Location
New Jersey
Actually so far they determined that its not Heads, Spark plugs, wires or coils....Which I determined before. But they capped diagnostics at 500, so at least that
So if its confirmed that its not what you already figured out, is there ultimately a solution, or does it end there? In other words —can you continue to utilize the Jeep and simply say, "F it" with the CEL's?
 

Rdartua

Member
Joined
Nov 29, 2021
Messages
39
Location
06831
No they are still working on it, Keith - service manger said they are determined. Oh sure I can drive with CEL's, but why? been driving 30 year not having engine light on in any of my cars without immediately taking care of it - I think at this point its a matter of principle.
Honestly, I am really itching to trade it in for 2014 GX460 - just so much more solid platform with ridiculous life span and descent aftermarket mods. But my kids wants the jeep for the top off thing ;-)
 

Gatorlaw

New Member
Joined
Sep 6, 2021
Messages
17
Location
Florida
I’m curious to see the resolution because I’m still dealing with the same. I have found that so long as I keep the idol over 1500 until coolant temp reaches 150 I don’t get the misfire or the light. But if I don’t do that I get the cel and the misfire that goes away. Not the coils or the plugs. It has to be something electrical but this engine is a wiring nightmare and I don’t know where to start.
 

Rdartua

Member
Joined
Nov 29, 2021
Messages
39
Location
06831
I’m curious to see the resolution because I’m still dealing with the same. I have found that so long as I keep the idol over 1500 until coolant temp reaches 150 I don’t get the misfire or the light. But if I don’t do that I get the cel and the misfire that goes away. Not the coils or the plugs. It has to be something electrical but this engine is a wiring nightmare and I don’t know where to start.
Did you attach a scanner? do you know which cylinders specifically are misfiring?
 

Gatorlaw

New Member
Joined
Sep 6, 2021
Messages
17
Location
Florida
Yes. I get p300 and then (depending on ? ) I will get 301,303,305. Only had all 3 show up a couple times. Usually it is either 1 or 5, if I let it trigger.
 

Gatorlaw

New Member
Joined
Sep 6, 2021
Messages
17
Location
Florida
Yep. Since the misfire only occurs on cold start and disappears as soon as temp is over 150 it’s hard to figure out. Not wanting to toss parts at it. And done paying diagnostic fees for no cure. So I just run the idle high (1500 rpm till 150). Keeps the cel off.
 

Rdartua

Member
Joined
Nov 29, 2021
Messages
39
Location
06831
Insane how similar these issues, I found multiple forums dealing with this specific issue with no-one figuring it out and just trading in the car. There is no magic, has to be something that can be diagnosed.
 

Gatorlaw

New Member
Joined
Sep 6, 2021
Messages
17
Location
Florida
I’m not trading (I’m sure that’s why the last owner probably did so) I’m just gonna run it till it dies and swap the engine. I’m planning on building this and keeping for a long time. I’ll never get out what I put in but I’ll have fun and make memories along the way.
 
  • Like
Reactions: BLACKJKU

Rdartua

Member
Joined
Nov 29, 2021
Messages
39
Location
06831
I’m not trading (I’m sure that’s why the last owner probably did so) I’m just gonna run it till it dies and swap the engine. I’m planning on building this and keeping for a long time. I’ll never get out what I put in but I’ll have fun and make memories along the way.
A romantic, lol. I hear you, I was kind of thinking same - but still wanted to get some time out of this engine.
 

Gatorlaw

New Member
Joined
Sep 6, 2021
Messages
17
Location
Florida
A romantic, lol. I hear you, I was kind of thinking same - but still wanted to get some time out of this engine.
I’m the same. I check all fluids do the maintenance, run scans and look for other signs but if all I have is this intermittent misfire at start up I don’t think it will effect longevity. It’s at 163k so far so…
 

Vman

JK Enthusiast
Joined
Aug 23, 2021
Messages
192
Location
Pacific NW
I’m curious to see the resolution because I’m still dealing with the same. I have found that so long as I keep the idol over 1500 until coolant temp reaches 150 I don’t get the misfire or the light. But if I don’t do that I get the cel and the misfire that goes away. Not the coils or the plugs. It has to be something electrical but this engine is a wiring nightmare and I don’t know where to start.

That's interesting.

Have you tested the throttle body?
 

Rdartua

Member
Joined
Nov 29, 2021
Messages
39
Location
06831
Well....They hit the wall and admitted it. They are saying its now throwing cam vs crankshaft sensor so 2 choices either open timing chain or drop oil pen to continue diagnosis. BTW it never had this code before. They opened a case with Chrysler and that came up empty. - They are all stumped...Service manager said it would be cheaper to replace engine then for them to continue to tear into the engine. This is definitely first and last Chrysler product I will ever buy. Soooo, picking up the car on Friday, with $500 down the drain.
They did find that fuel rail 10lb lower then require 58lb of pressure, but that would not impact cylinder 1 and 2 especially at idle...

Any gurus out there or pentastar gods out there that maybe can take a guess at what's happening?
 
Last edited:
  • Sad
Reactions: mrjp

Threepointsix

JK Enthusiast
Joined
Dec 11, 2020
Messages
235
Location
New Jersey
Well....They hit the wall and admitted it. They are saying its now throwing cam vs crankshaft sensor so 2 choices either open timing chain or drop oil pen to continue diagnosis. BTW it never had this code before. They opened a case with Chrysler and that came up empty. - They are all stumped...Service manager said it would be cheaper to replace engine then for them to continue to tear into the engine. This is definitely first and last Chrysler product I will ever buy. Soooo, picking up the car on Friday, with $500 down the drain.
They did find that fuel rail 10lb lower then require 58lb of pressure, but that would not impact cylinder 1 and 2 especially at idle...

Any gurus out there or pentastar gods out there that maybe can take a guess at what's happening?
There it is! Exactly as I suspected. Dealers are not real mechanics who correct or fix an issue. Or its 'dealer protocol' to make margins. They throw their hands up, along with a bill and recommend a new effing engine! Unbelievable, but not. It seems to happen every time they're stumped.

Judging by your zip code you're way up north. There is one guy that posts YouTube videos of step-by-step Pentastar repairs. His videos are so well edited and you can tell he's a meticulous mechanic. Thats the guy I would go to if this were to happen to me. The caveat is that he's in Georgia. But it never hurts to call him and see what he suggests:

The Motorcity Mechanic Garage
3896 Wrightsboro Rd Suite A,
Augusta, GA 30909
(706) 426-3306


 
  • Like
Reactions: mrjp

Rdartua

Member
Joined
Nov 29, 2021
Messages
39
Location
06831
There it is! Exactly as I suspected. Dealers are not real mechanics who correct or fix an issue. Or its 'dealer protocol' to make margins. They throw their hands up, along with a bill and recommend a new effing engine! Unbelievable, but not. It seems to happen every time they're stumped.

Judging by your zip code you're way up north. There is one guy that posts YouTube videos of step-by-step Pentastar repairs. His videos are so well edited and you can tell he's a meticulous mechanic. Thats the guy I would go to if this were to happen to me. The caveat is that he's in Georgia. But it never hurts to call him and see what he suggests:

The Motorcity Mechanic Garage
3896 Wrightsboro Rd Suite A,
Augusta, GA 30909
(706) 426-3306


Thank you so much for the suggestion, will try to give him a call.