Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK2 - > Trouble Shooting/Problems/Service

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 08-18-2013, 08:55 PM
Yadkin's Avatar
Senior Member
My Jeep: 2012 3.6L WK2
 
Join Date: Mar 2012
Location: Yadkin Valley, NC
Posts: 1,249
Thanks: 0
Thanked 18 Times in 18 Posts
Rep Power: 202301
Yadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond repute
Code P0302, related to towing?

I picked up a UHaul trailer in Boone, NC (elevation 3300 feet) on Friday afternoon and hauled it empty up to my cabin in the mountains. Lots of long, steep grades and the Jeep handled it well. When I got to my cabin (elevation 4900) I unhooked it to do errands on Saturday morning. On my way back up the mountain (no trailer) the check engine light went on with no EVIC message. When I got to the cabin I parked it, and in the morning checked the oil and all the fluids and everything was fine.

Then I hooked the trailer back on and loaded it up with furniture and drove down the mountain, stopping at home (elevation 800) to spend the night, and then used my reader to find code P0302 "misfire on cylinder #2". There was no misfire on the V6; heck I can tell if there's a misfire on a V8. I reset the code it immediately came back on, and I tried that twice.

The next day I drove it on to Raleigh (elevation 315) with the trailer full of furniture and it ran perfectly, but the engine light on the entire time. I unloaded the furniture in Raleigh then dropped the trailer off at UHaul there. When I restarted to leave UHaul the light turned off after the initial prove-out.

100 miles later, back home and the light never came back on.

All this was on the same tank of gas.

I make these same trips and elevation changes often, about twice/ month on average.

Weird. Any thoughts on what the issue was?
__________________

__________________
Reply With Quote
  #2  
Old 08-18-2013, 09:01 PM
Scottina06's Avatar
JeepGarage Founder
My Jeep: 2014 6.4L SRT8 WK2
 
Join Date: May 2009
Location: Berea, Kentucky
Posts: 49,211
Thanks: 866
Thanked 969 Times in 684 Posts
Rep Power: 7717841
Scottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond repute
Garage
Re: Code P0302, related to towing?

gonna need a new head
__________________

__________________
SCOTT
The HARDER you work...the LUCKIER you are!
2014 REDLINE red Jeep SRT "BLOODIED\BlackOps CFR Edition" 1 of 1
2013 JKU Wrangler 10A-stormtrooper'ed, JW Speaker and more!
Previous JEEP rides-
2013 Jeep Grand Cherokee SRT-deep cherry
2006 Jeep Grand Cherokee Laredo-inferno red



Twitter-The_Jeep_Guy
Instagram-thejeep_guy

Reply With Quote
  #3  
Old 08-19-2013, 08:14 AM
padgett's Avatar
Premium Member
 
Join Date: Feb 2012
Location: Orlando
Posts: 1,534
Thanks: 0
Thanked 24 Times in 21 Posts
Rep Power: 80149
padgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond repute
Re: Code P0302, related to towing?

P030x is set when misfires exceed A Lot. 300 is several cyl, 302 means #2 cyl. This is a common indicator on a 3.6 of the head ailment common to '12s.

I check for misfires every month but sofar is in the 0-2 range.
Reply With Quote
  #4  
Old 08-19-2013, 08:48 AM
Yadkin's Avatar
Senior Member
My Jeep: 2012 3.6L WK2
 
Join Date: Mar 2012
Location: Yadkin Valley, NC
Posts: 1,249
Thanks: 0
Thanked 18 Times in 18 Posts
Rep Power: 202301
Yadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond repute
Re: Code P0302, related to towing?

This "common head ailment", is there a service bulletin on it?
__________________
Reply With Quote
  #5  
Old 08-21-2013, 09:29 AM
Yadkin's Avatar
Senior Member
My Jeep: 2012 3.6L WK2
 
Join Date: Mar 2012
Location: Yadkin Valley, NC
Posts: 1,249
Thanks: 0
Thanked 18 Times in 18 Posts
Rep Power: 202301
Yadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond repute
Re: Code P0302, related to towing?

There must be, since they are changing the cylinder head under warranty, and had all the parts in stock.
__________________
Reply With Quote
  #6  
Old 08-21-2013, 10:46 AM
padgett's Avatar
Premium Member
 
Join Date: Feb 2012
Location: Orlando
Posts: 1,534
Thanks: 0
Thanked 24 Times in 21 Posts
Rep Power: 80149
padgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond reputepadgett has a reputation beyond repute
Re: Code P0302, related to towing?

CJF% knows about the issue but has avoided releasing a public TSB. It does seem to relate to load, temperature, and gas quality.

If I were towing a load in the hills on a hot day suspect I would use 89 PON
Reply With Quote
  #7  
Old 08-21-2013, 01:39 PM
Yadkin's Avatar
Senior Member
My Jeep: 2012 3.6L WK2
 
Join Date: Mar 2012
Location: Yadkin Valley, NC
Posts: 1,249
Thanks: 0
Thanked 18 Times in 18 Posts
Rep Power: 202301
Yadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond repute
Re: Code P0302, related to towing?

The vehicle is rated to tow 5000#, and the trailer weighed a fraction of that. Also, there is nothing in the OM that says to use a higher octane fuel when towing.

I've had no performance problems with this engine.
__________________
Reply With Quote
  #8  
Old 08-22-2013, 08:07 AM
Maliberti's Avatar
Member
My Jeep: 2014 3.6L WK2
 
Join Date: Feb 2012
Posts: 60
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 994
Maliberti is on a distinguished road
Garage
Re: Code P0302, related to towing?

I had the same issue with the CEL. I was not towing.
I also had no performance issue.

Just had the heads replaced under warranty, they had my car for 2 weeks.

I thing I noticed after the new heads was the car does not steam out of exhaust.

This car from day one always had slight steam coming out of exhaust in the morning, regardless of temperature and this would be like this on every cold start. They told me this is normal of all cars, and I too believed them as every car I have owned did this in the morning when it was cold, but this car was doing it regardless of temp and it would last well beyond the warm up period, now its gone.
__________________

__________________
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wk2 p0302 cylinder misfire clarue Trouble Shooting/Problems/Service 3 01-18-2013 07:31 PM
P0302 Check engine light keeps coming on billybronco1 Trouble Shooting/Problems/Service 10 12-21-2012 11:37 PM
Towing questions. First time towing looking for some input. JTS97Z28 Grand Cherokee - WK2 - 5 08-25-2012 03:53 PM
OBD code P2667 Input Speed Sensor code Greg.garvin@gmail.com Troubleshooting/Problems Discussion 1 08-19-2012 01:51 AM
OBD code P2667 Input Speed Sensor code Greg.garvin@gmail.com Trouble Shooting/Problems/Service 0 08-18-2012 08:10 PM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 09:31 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community