Wrangler 392 Blown Head Gasket

dan392 · Sep 17, 2023

Ron392 said:
Wow, I appreciate your research, Thank you! Look what’s available now on K&N’s website. An actual drop in high performance air filter, 33-5127. This is an actual game changer folks, this will allow you to keep your factory box & utilize your hydro-glide as it was designed, to pass cold air. I just ordered a filter for myself, hopefully K&N will do the right thing and allow me to send back the previous air intake system I bought, I’ll keep you’ll posted.

www.knfilters.com/33-5127-replacement-air-filter

Just be aware that these filter types are not that good at filtering dust. Mopar's own cold air filter warns against using it in dusty conditions.

Ron392 · Sep 17, 2023

dan392 said:
Just be aware that these filter types are not that good at filtering dust. Mopar's own cold air filter warns against using it in dusty conditions.

You have a valid point and the hydro-guide can easily channel dust and dirt through the intake especially if you go off-roading potentially damaging the motor if your filter isn’t adequately catching all debris. There is a difference though between the dry media performance filter Mopar sells for the 3.6L engines and the K&N design of layered oiled cotton media.

Ron392 · Sep 18, 2023

Ron392 said:
You have a valid point and the hydro-guide can easily channel dust and dirt through the intake especially if you go off-roading potentially damaging the motor if your filter isn’t adequately catching all debris. There is a difference though between the dry media performance filter Mopar sells for the 3.6L engines and the K&N design of layered oiled cotton media.

Update, The dealer said this and I quote: Looked like 6 injectors were sticking caused the issue now have 8 new injectors. The failure was the injectors caused the problem, Dumps to much fuel burns very hot much hotter. Now I’m not an expert here but how is it even possible that the injectors could blow a head gasket

I also asked about the thermostat and if it would be replaced, he said no as there was no codes and he can’t replace parts unless an error code was present. $500+ to have the dealer to replace the thermostat out of pocket, I won’t pay that! I can’t wait to see the work order.

Robr651 · Sep 18, 2023

Ron392 said:
Update, The dealer said this and I quote: Looked like 6 injectors were sticking caused the issue now have 8 new injectors. The failure was the injectors caused the problem, Dumps to much fuel burns very hot much hotter. Now I’m not an expert here but how is it even possible that the injectors could blow a head gasket I also asked about the thermostat and if it would be replaced, he said no as there was no codes and he can’t replace parts unless an error code was present. $500+ to have the dealer to replace the thermostat out of pocket, I won’t pay that! I can’t wait to see the work order.

6 sticking injectors with 15k miles? What fuel do you run? Anything specific or whatever is cheapest? Just curious

Ron392 · Sep 18, 2023

Robr651 said:
6 sticking injectors with 15k miles? What fuel do you run? Anything specific or whatever is cheapest? Just curious

I did purchase the vehicle used with around 8k miles. I only put premium 91 octane. Averaging 11 mpg, maybe the new injectors will improve fuel economy.

dan392 · Sep 18, 2023

Ron392 said:
You have a valid point and the hydro-guide can easily channel dust and dirt through the intake especially if you go off-roading potentially damaging the motor if your filter isn’t adequately catching all debris. There is a difference though between the dry media performance filter Mopar sells for the 3.6L engines and the K&N design of layered oiled cotton media.

This was the result of me using a K&N (the oily one but using the OE filter box). Me personally would never use any other filter but stock ever again.

Ron392 · Sep 18, 2023

dan392 said:
This was the result of me using a K&N (the oily one but using the OE filter box). Me personally would never use any other filter but stock ever again.

View attachment 26179

Thanks for sharing, Is this from a 2.0/3.6 or 6.4? That’s the bottom or top of the box? Do you live in an environment thats dusty. Do you frequent trails or our a mostly a mall crawler?

dan392 · Sep 18, 2023

Ron392 said:
Thanks for sharing, Is this from a 2.0/3.6 or 6.4? That’s the bottom or top of the box? Do you live in an environment thats dusty. Do you frequent trails or our a mostly a mall crawler?

A 3.6. Driving both city and off road trails in Arizona. That filter was on my Jeep only for a few months before I got rid of it.

A wider shot:

dan392 · Sep 18, 2023

Ron392 said:
Do you have a few images of the top and bottom of the filter please.

Sorry but I don't. Those pictures were from last year. The Jeep is all in one piece now. As one part of that project was to replace the K&N filter (this one https://www.amazon.com/gp/product/B000Q3OTQC) with a Mopar one (this one https://www.rockauto.com/?carcode=1504794&parttype=10435). I was almost done when I've noted on the Mopar instructions that this filter was not to be used in a "dusty environment". I looked to find the instructions to take a picture of it but can't find the instruction paper anymore.

Ron392 · Sep 18, 2023

dan392 said:
Sorry but I don't. Those pictures were from last year. The Jeep is all in one piece now. As one part of that project was to replace the K&N filter (this one https://www.amazon.com/gp/product/B000Q3OTQC) with a Mopar one (this one https://www.rockauto.com/?carcode=1504794&parttype=10435). I was almost done when I've noted on the Mopar instructions that this filter was not to be used in a "dusty environment". I looked to find the instructions to take a picture of it but can't find the instruction paper anymore.

Wow! That’s really something! Thank you for sharing, I defiantly will proceed with caution. Hopefully u didn’t have any engine damage.

Robr651 · Sep 19, 2023

Ron392 said:
I did purchase the vehicle used with around 8k miles. I only put premium 91 octane. Averaging 11 mpg, maybe the new injectors will improve fuel economy.

Use top tier fuel. Not every fuel station is top tier regardless of octane rating. This is from the owners manual:

Besides using unleaded gasoline with the proper octane rating, gasolines that contain detergents, corrosion and stability additives are recommended. Using gasolines that have these additives will help improve fuel economy, reduce emissions, and maintain vehicle performance.
Designated TOP TIER Detergent Gasoline contains a higher level of detergents to further aide in minimizing engine and fuel system
deposits. When available, the usage of TOP TIER Detergent gasoline is recommended. Visit
www.toptiergas.com for a list of TOP TIER Detergent Gasoline Retailers.

Ron392 · Sep 19, 2023

Robr651 said:
Use top tier fuel. Not every fuel station is top tier regardless of octane rating. This is from the owners manual:

Besides using unleaded gasoline with the proper octane rating, gasolines that contain detergents, corrosion and stability additives are recommended. Using gasolines that have these additives will help improve fuel economy, reduce emissions, and maintain vehicle performance.
Designated TOP TIER Detergent Gasoline contains a higher level of detergents to further aide in minimizing engine and fuel system
deposits. When available, the usage of TOP TIER Detergent gasoline is recommended. Visit
www.toptiergas.com for a list of TOP TIER Detergent Gasoline Retailers.

Another person providing great information, Thank you. Oddly enough I fill up at BJ’s and they our not on the list. I wonder why, gotta do further research. Personally I think the previous owner did not use premium gas and perhaps that is the reason

unless someone can better Elaborate.

Robr651 · Sep 19, 2023

Ron392 said:
Another person providing great information, Thank you. Oddly enough I fill up at BJ’s and they our not on the list. I wonder why, gotta do further research. Personally I think the previous owner did not use premium gas and perhaps that is the reason unless someone can better Elaborate.

Most of the cheaper stations around don’t use the same detergents as the Top Tier ones do in their gasoline. That’s why I asked what fuel you were running. Costco is usually cheaper but also is considered Top Tier if you have one in your area. Just food for thought when you get your Jeep back. I’m still surprised that you’d have that many failed / fouled injectors but subpar fuel could be the reason.

Fast-n-Furious · Sep 19, 2023

Robr651 said:
Most of the cheaper stations around don’t use the same detergents as the Top Tier ones do in their gasoline. That’s why I asked what fuel you were running. Costco is usually cheaper but also is considered Top Tier if you have one in your area. Just food for thought when you get your Jeep back. I’m still surprised that you’d have that many failed / fouled injectors but subpar fuel could be the reason.

Totally agree with you. I always use Top Tier 92 or 93 when available. Some of my local gas stations used to have the Top Tier certification/sticker then some no longer listed there. There's also a summer-blend gas and a winter gas essentially: https://blog.amsoil.com/the-difference-between-winter-and-summer-blend-gas/

I also run Techron to prevent some carbon buildup but haven't been following a fixed schedule.

Ron392 · Sep 20, 2023

Fast-n-Furious said:
Totally agree with you. I always use Top Tier 92 or 93 when available. Some of my local gas stations used to have the Top Tier certification/sticker then some no longer listed there. There's also a summer-blend gas and a winter gas essentially: https://blog.amsoil.com/the-difference-between-winter-and-summer-blend-gas/

I also run Techron to prevent some carbon buildup but haven't been following a fixed schedule.

What’s your take on BJ’s gas. I am not the original owner of this 392. I fill up weekly and use 93

Donkey's Dad · Sep 20, 2023

I checked out the Top Tier website. I'm going to call a measured amount of BS on it. Here's why:

In my area, I buy gas at Casey's or Kum & Go because they carry ethanol free premium (In Oklahoma, you can only get 91 Octane without ethanol).
Neither Casey's or Kum & Go are on the "Top Tier" brand list, but Quick Trip is among others like Conoco, Shell, Philips 66, none of which are near me in any way.
Quick Trip does not have Ethanol Free Premium, not sure about the others but I suspect they don't either around here...
In order to get the "Top Tier" cert and display it on your pumps, you have to pay a licensing fee, which adds to the cost per gallon.
Quick Trip has pretty cheap gas, but again not ethanol free. so I can't see them having a higher quality fuel product at a lower price than the ethanol free premium I get at the stations that carry it.

In short, I suspect that the Top Tier website is set up to drive you to the stations that pay the licensing fees above all else. If the stations don't pay that fee, and therefore can't display that certification, it may not necessarily mean their fuel is sub standard... There may also be a component of this designed to drive people to fuels WITH ethanol...

Unless someone from a fuel blending and supply company can chime in to provide concrete evidence that the ethanol free non-top tier fuels are not as good as the ethanol blends, I'm sticking with ethanol free. Just my two cents.

guruman · Sep 20, 2023

Donkey's Dad said:
I checked out the Top Tier website. I'm going to call a measured amount of BS on it. Here's why:

In my area, I buy gas at Casey's or Kum & Go because they carry ethanol free premium (In Oklahoma, you can only get 91 Octane without ethanol).

Neither Casey's or Kum & Go are on the "Top Tier" brand list, but Quick Trip is among others like Conoco, Shell, Philips 66, none of which are near me in any way.

Quick Trip does not have Ethanol Free Premium, not sure about the others but I suspect they don't either around here...

In order to get the "Top Tier" cert and display it on your pumps, you have to pay a licensing fee, which adds to the cost per gallon.

Quick Trip has pretty cheap gas, but again not ethanol free. so I can't see them having a higher quality fuel product at a lower price than the ethanol free premium I get at the stations that carry it.

In short, I suspect that the Top Tier website is set up to drive you to the stations that pay the licensing fees above all else. If the stations don't pay that fee, and therefore can't display that certification, it may not necessarily mean their fuel is sub standard... There may also be a component of this designed to drive people to fuels WITH ethanol...

Unless someone from a fuel blending and supply company can chime in to provide concrete evidence that the ethanol free non-top tier fuels are not as good as the ethanol blends, I'm sticking with ethanol free. Just my two cents.

I have to agree. My father-in-law started a chain of c-stores in the late 70's, they merged with a regional petro distributor.

One of the things I learned from him was that all of the local stations, regardless of brand, get fuel at the same distribution terminal, and there is a limited number of tanks, and therefor a limited number of actual blends.

He had some stores with Marathon and some with Shell branding. and anytime someone would say that they preferred one over the other, he would make it a point to let them know that the exact same truck filled the underground tanks at both stores.

Robr651 · Sep 20, 2023

guruman said:
I have to agree. My father-in-law started a chain of c-stores in the late 70's, they merged with a regional petro distributor.

One of the things I learned from him was that all of the local stations, regardless of brand, get fuel at the same distribution terminal, and there is a limited number of tanks, and therefor a limited number of actual blends.

He had some stores with Marathon and some with Shell branding. and anytime someone would say that they preferred one over the other, he would make it a point to let them know that the exact same truck filled the underground tanks at both stores.

The base fuel is basically the same, it’s the detergents / additive pack that the “Top Tier” suppliers add to their fuel. The same argument could be made for why not use Walmart branded 0W40 motor oil as opposed to Penzoil or another name brand oil. It’s not only the base oil but the additive and detergent pack that you’re paying for… well that and a whole lot of marketing. To each their own on what they want to run in their Jeep.

CPT Papa · Sep 20, 2023

Ron392 said:
Update, The dealer said this and I quote: Looked like 6 injectors were sticking caused the issue now have 8 new injectors. The failure was the injectors caused the problem, Dumps to much fuel burns very hot much hotter. Now I’m not an expert here but how is it even possible that the injectors could blow a head gasket I also asked about the thermostat and if it would be replaced, he said no as there was no codes and he can’t replace parts unless an error code was present. $500+ to have the dealer to replace the thermostat out of pocket, I won’t pay that! I can’t wait to see the work order.

I am not the 392 expert but in every engine I have worked on more fuel makes it run cooler not hotter. The fuel is a lubricant and if to much fuel it burns poorly with lower exhaust gas temp. Its always a balance between lean/extra wear/hot/good fuel economy and rich/longevity/cooler/gas guzzler. I just don't trust dealer mechanics anymore. If the computer doesn't provide a code with step by step instructions they cant fix it.

Bobo57 · Sep 20, 2023

CPT Papa said:
I am not the 392 expert but in every engine I have worked on more fuel makes it run cooler not hotter. The fuel is a lubricant and if to much fuel it burns poorly with lower exhaust gas temp. Its always a balance between lean/extra wear/hot/good fuel economy and rich/longevity/cooler/gas guzzler. I just don't trust dealer mechanics anymore. If the computer doesn't provide a code with step by step instructions they cant fix it.

Spot on