Spark plug change on 2017 jeep grand cherokee 3.6

[D60]

I work on a fleet of a few hundred promasters with 3.6s. Every one is leaking, it’s to the point where I’m only replacing them when they’re leaking onto the ground (which means the valley has filled up with about 3” of oil, flowed down the back, down the bellhousing, filled up any cavities and places to pool on the transmission case and finally spilled over and drips to the ground).

if I worked in a real shop, every one would be getting written up to replace. Being a fleet shop, and I’m 1 of 2 guys willing to do the work, I just can’t keep up.

Ours are all 2018s with about 18-30k miles on them.

Have you ever tried the Dorman? I'm not advocating for it, just genuinely curious.

99.999% of the time my policy is to run from Dorman anything but this might be an exception

 

[t1snwrbrdr12]

Have you ever tried the Dorman? I'm not advocating for it, just genuinely curious.

99.999% of the time my policy is to run from Dorman anything but this might be an exception

We were getting the dormans but I never personally installed one. They haven’t come back yet, though, so that is a good sign.

Lately we are only installing OEM again.

At first we were installing aftermarket (unknown brand) and they were blowing a plug out of them within days (we lost a few engines that year as our drivers really just don’t care about anything and will just keep on trucking till they lock them up).

 

[D60]

We were getting the dormans but I never personally installed one. They haven’t come back yet, though, so that is a good sign.

Lately we are only installing OEM again.

At first we were installing aftermarket (unknown brand) and they were blowing a plug out of them within days (we lost a few engines that year as our drivers really just don’t care about anything and will just keep on trucking till they lock them up).

Yeah I'm thinking the Dorman probably can't be any worse than OEM, but I don't want them to hear that because their immediate thought would be: "CHALLENGE ACCEPTED!"

 

[t1snwrbrdr12]

I didn't think the OEM replacements ever came with the sensors, but I'm probably mixing it up with all the other supply chain issues..

Like @t1snwrbrdr12 said, these things can dribble for a long time before they get bad enough to fill the block valley and dribble over. That's why I mentioned above to poke around for a hot/burning oil smell under the hood.

Another tell-tale is is you rinse out the engine bay with water. You will see a huge rainbow sheen on the ground long before oil starts dripping to the ground.

I was just thinking (after fighting one at work today) I would advise against rinsing under hood of a 3.6. There’s a couple of screws for the upper intake plenum that are recessed deep, water collects in these holes and has no way to escape. I’m fighting quite a few lately because this water in turn rusts the screw heads and makes it hard to get a socket on them (I’ve seen one guy take a bit to it and grind the head off, which isn’t fun due to it being in a non-visible spot, at least on these promasters with the cowl over top of everything you’re doing).

I understand most every other 3.6 out there has an engine cover on them, so this may not be an issue. Even if it does, I’d still advise if you do rinse off underhood, blow out those two or three intake plenum screw holes so your screws don’t rust up.

 

[D60]

I was just thinking (after fighting one at work today) I would advise against rinsing under hood of a 3.6. There’s a couple of screws for the upper intake plenum that are recessed deep, water collects in these holes and has no way to escape. I’m fighting quite a few lately because this water in turn rusts the screw heads and makes it hard to get a socket on them (I’ve seen one guy take a bit to it and grind the head off, which isn’t fun due to it being in a non-visible spot, at least on these promasters with the cowl over top of everything you’re doing).

I understand most every other 3.6 out there has an engine cover on them, so this may not be an issue. Even if it does, I’d still advise if you do rinse off underhood, blow out those two or three intake plenum screw holes so your screws don’t rust up.

Interesting, would be nice to know the specs and replace with stainless.

On my JL the engine cover got filed into the big round bin on Day #1 ......I'm just kind of a minimalist when it comes to trail rigs

 

[t1snwrbrdr12]

Interesting, would be nice to know the specs and replace with stainless.

On my JL the engine cover got filed into the big round bin on Day #1 ......I'm just kind of a minimalist when it comes to trail rigs

They’re just a coarse threaded self tapping type screw. If I remember next time I can measure length.

 

[Thermo1223]

I did it on the 3.6 in a Dodge GC and it was fairly easy consider it being transverse. I never replaced the gaskets and lasted another 100k without incident. I used OEM Champion plugs just like what came out.

Also speaking of the oil cooler, that one never leaked that I could see but at 200k+ it was going to be replaced because a pressure sensor went. Fortunately the vehicle was traded in before that came to be my job.

 

[DGXR]

Got myself 2 cans of carb cleaner so I can clean out throttle body and everything around it.

I would use a TB-specific cleaner on the TB internals. Carb cleaner is OK for the exterior stuff.

 

[JTK]

I was just thinking (after fighting one at work today) I would advise against rinsing under hood of a 3.6. There’s a couple of screws for the upper intake plenum that are recessed deep, water collects in these holes and has no way to escape. I’m fighting quite a few lately because this water in turn rusts the screw heads and makes it hard to get a socket on them (I’ve seen one guy take a bit to it and grind the head off, which isn’t fun due to it being in a non-visible spot, at least on these promasters with the cowl over top of everything you’re doing).

I understand most every other 3.6 out there has an engine cover on them, so this may not be an issue. Even if it does, I’d still advise if you do rinse off underhood, blow out those two or three intake plenum screw holes so your screws don’t rust up.

That is a good call. Are these particular fasteners like the other "wood screws" that hold the upper plenum on? I wonder if a shot of fluid film or a dab of silicone grease down the recess might help as preventative maintenance. I hate a dirty engine bay. LOL

 

[Jimmy_Russells]

It’s a stupid design, but I’m still 100% convinced that every one that has failed is due to over tightening. All you need to do is go till it stops, absolutely no more than that. I barely need a wrench to remove mine, no leaks at 90k. *knock on wood*

I torqued mine to 17-18 ft lbs, which is the spec, and I still had two fail, both right around 60k.

Sometimes the plastic welded plugs in it fail, sometimes it's the o-rings between it and the block.

 

[ruSSrt]

Hey guys. Question about PCV valve. I just got it in the mail and something is rattling on inside of it. Is there a plunger? Is it supposed to do that? Before I take old one out, I want to make sure I got functioning valve to replace it with.

 

[D60]

Typically rattling in a PCV valve is good

 

[ruSSrt]

Typically rattling in a PCV valve is good

Thank you.

 

[t1snwrbrdr12]

Interesting, would be nice to know the specs and replace with stainless.

On my JL the engine cover got filed into the big round bin on Day #1 ......I'm just kind of a minimalist when it comes to trail rigs

Here’s what I was talking about with the two upper plenum screws that are recessed down a hole that will collect water and rust away.

 

[dave940]

Stumbled across this thread and would add that the Dorman housing with cooler can be found at JEGS, $164. I'm waiting for mine to ship directly from Dorman next week. There are dozens of "chinesium" versions on Amazon, but I'm hoping that the Dorman, being the only US made aluminum housing AFAIK, will be of slightly better quality. I have a nephew who works at a dealership garage who warned me that I'm on borrowed time, but so far I have zero leaks on my 3.6l Pentastar in a 2015 Charger. Still, I will likely wait until spring to change it out.
Because of the accessibility problem, I plan on changing the oil pressure sensor because of the poor track record of OEM sensors. My dilemma is whether to install a new OEM, or go with Dorman for that too. I can't find anything on better replacement oil sensors. Never thought about the PCV until reading this thread, may do it too. Also planning on replacing spark plugs, even though they only have about 70k miles. Haven't posted this on a Dodge forum in fear of being overrun by fanboys. I have never been a fan of Chrysler products since their fall in the early 70's, and their current ownership inspires no confidence. Ended up in a Charger because I needed a full size AWD sedan and it was the only option at the time.

 

[MattPersman]

Here’s what I was talking about with the two upper plenum screws that are recessed down a hole that will collect water and rust away.

Yes the 14 thru I think 16 promaster were the worst on those. There were many plenums sacrificed to get to something lower in those years. I’m pretty good at getting most of them but occasionally it’s so gone there is almost nothing to grab (screw head wise) with any method

 

[MattPersman]

They revised the 7 plenum screws to not have the torx drive any longer in the middle so water couldn’t sit in that part as well that has helped as well

 

[t1snwrbrdr12]

Yes the 14 thru I think 16 promaster were the worst on those. There were many plenums sacrificed to get to something lower in those years. I’m pretty good at getting most of them but occasionally it’s so gone there is almost nothing to grab (screw head wise) with any method

We might have 10 or so 2016s and a few hundred 2018s. The 2018s still have the issue as well.

 

[Allaneddie]

From my experience: MOPARs always take Champions

 

[Capt W]

I didn't think the OEM replacements ever came with the sensors, but I'm probably mixing it up with all the other supply chain issues..

Depends how you order it. I bought Mopar p/n 68596317AA about three weeks ago. The overall part is called the adapter, which includes the body, a new filter, the cooler, and both sensors (temp and pressure).