WK2 (2012 Grand Cherokee) coolant leak - oil cooler housing replacement

psimurda · Sep 19, 2022

Hello all,
There was quite a big leak of coolant under my lower intake manifold. It is leaking from oil cooler. I am going to replace the whole oil cooler housing, do you think is it worth to replace the whole oil cooler housing with alluminium one (something like this: Dorman Products - PA900389) Or do you think keeping the plastic original one and replacing just orings/gaskets is fine? I am thinking "Since I am there already" I could probably change that. But not sure if it is worth. I heard the plastic housing breaks easily when changing oil and tighting too much.

ColdCase · Sep 19, 2022

There are a few threads on the subject, including instructions. There are advantages and disadvantages to all three methods. If no one jumps in here or you can't find them by the time I get back I'll take a look. Just wanted to mention to look around while waiting for someone to jump in, as that may be awhile.

psimurda · Sep 19, 2022

I've tried to look at - I found some info that it is better to buy the whole thing with air cooler and filter: Dorman Products - 926-959
Becausue just the housing may not fit for GC 2012 - which makes sense and I'd rather do that.

I was mostly interested in how long those housings last if orings, seals or gaskets break fast or in general what is the quality. I don't want to end up replacing that in next 1k miles because of blown oring again.

BigTizzie · Sep 20, 2022

Might as well do the drivers side spark plugs too while you have it apart.

Bilko · Sep 20, 2022

It's not the housing that is different. It's the actual cooler. The cheaper version for newer, post-2013 Pentastar engines reuses the oil cooler from your original housing. The pre-2013 cooler does not fit so you need to full kit which includes the cooler and also includes the newer oil filter design.

Big Tizzie 100% correct, if you have removed the intake manifold you should change the plugs. six genuine plugs cost about $30 and take less than 10 mins to swap out if the intake manifold is already removed. Some people also change the coils but to be honest I have never seen these fail on Pentastars so I wouldn't bother unless you have very high mileage, like 150K +.

If you plan to keep the vehicle for a while, I would go with the metal Doorman kit. Do not buy the $70 Amazon knock-offs unless you plan to sell the car within 6-12 months.

The Dorman kits come with all the gaskets and seals you need. I have installed a few on my buddies' Wranglers and have not experienced any issues. Chrysler should use these as standard.

psimurda · Sep 20, 2022

Thanks for all advices and comments, I really appreciate it! Oh yeah I am doing spark plugs for sure! They are not bad, but since I am there.. it is worth of replacing.

I ended up buying the whole housing and decided to upgrade to aluminium Dorman one, since they are cracks in the plastic and coolant is leaking from there - or maybe it is just the gasket - I don't think keeping it is worth it - the Oil cooler looks fine but I didn't manage to remove it from the housing (maybe too tight) anyway the housing comes with cooler too.
Here is the housing - place where it was leaking

and lots of coolant in the 'valley'

psimurda · Sep 20, 2022

The jeep has 128k miles I was hoping to keep it for 5ish years (I don't drive much, probably 5k-6k/year plus I have Subaru which I'll be still using). Good to know that Doorman aluminum housing is reliable!

I have few other questions, if I may:

I will probably skip the coils but I was thinking about fuel injectors - they look good, but is it worth replacing them? They don't look clogged or dirty, so I'd say not necessary.

Should I clean the engine intake? There is bit of carbon built in It is not apparent from the pic. If so, what would be the best method? I don't want the carbonated debris falling into the engine so maybe vacuum cleaner and light brush? I'll probably just wipe the outer parts where the intake manifold gasket goes, but what about inside?
I tried to take picture but I suck

it is bad picture

Is there any trick before putting the new oil cooler + housing back in? Like lube some gaskets? I was only checking manual for torque and order of tightening the bolts.

ColdCase · Sep 20, 2022

The O rings should be installed dry, do not use lube.

To oil or seal - Oil Cooler question

Replacing the oil cooler on our 2011 GC with the 3.6. Question, what is the best practice with the new o-rings. Oil them before installation ? Use grease ? User sealant instead? Wonder what has worked well for others. And of coarse what an awesome place to put a cooler! Thanks for any responses!

www.jeepforum.com

2012 JGC coolant leak real bad

2012 JGC limited 3.6 engine. Car over heated the other day pretty good just about got it home had to stop 2 times to add water. Every time I added water it would come out the back top side of the engine. When I re-started yes it would come out if you look under the jeep near the fire wall the...

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Bilko · Sep 23, 2022

You have probably completed the installation by now so maybe late advice. I would not bother trying clean the intake ports the risk of dropping crap into the engine far outways any benefit of having shiny intake ports, keep that Dremil locked away for this job

It looks like you will be needing to clean up the mating surfaces so stuff the intakes with shop towels and go old school and use a scraper then use a decent vacuum to clean up before and whilst you pull out the towels, this is easier and you will do a better job if you have a helper.

If it's not too late can you take some photos of the Dorman install? This is a common problem so they could be very useful for other forum members as our WK2s age.

Once you have the housing on and everything connected it's worth pressure washing the valley, before you refit the plastic intake manifold, else you will be smelling oil and coolant for the next 6 months. You need to be careful and use some engine degreaser first then use a lower pressure wash or maybe just a garden hose. If you don't have a full understanding of engines and electrical systems skip this step. Let everything dry off before firing up the engine.

psimurda · Sep 26, 2022

Actually I have not finished yet. I was buys with work and other stuff around house.
So far I have cleaned the contact surfaces, removed all fluids 'in the valley' - coolant and oil. I put the aluminum housing in and did compression test for cooling system - good news = no leaks! 17psi without any issues. Before it was leaking with 13ish psi and I could hear bubbling at around 11. I decided to do plugs as well.
Bad news = when I was listening for leaks under the oil housing I hit the pressurized radiator cap with pump on and it exploded, so I have coolant all over

any trick to remove that? Or is it safe I think it shouldn't cause any harm it was just bunch of it all over me, my clothes were soaked, on the hood, on the front of the car. Few drops on serpentine belt, alternator and engine cover and over battery - I tried to wiped everything. So far - fun project

I just need to put lower intake and intake manifold back in and make sure I am able to crank the engine with no engine check lights. I'll replace oil and add some additives to clean intake ports and flush coolant after I am done with all.

Here are some pictures...

Old spark plug:

Prepared for new oil housing

I tried to clean intake manifold

With the new oil housing in:

I tighten the oil housing to 106 in-lbs according the service manual.

It was bit tricky to put the whole housing between the intake ports as the aluminum housing have those valves which are not on the original plastic housing:

It required bit of moving around and figuring out the right tilt but not huge deal.

Bilko · Sep 26, 2022

Looks like a great install.

I have done a few of these after each one I say never again!

Coolant is not great for serpentine belts. once everything is back together just give it a good wash with your garden hose and it should be fine. Have you ever changed the belt before? I do not what the official maintenance schedule is. If you have 128k miles and you do not know it has been changed, I would swap it for the sake of $30 and literally 5 mins of effort. Throw the old one under the floor with your spare wheel just in case.

9496ZJs · Sep 27, 2022

Wow, what a project! Nice work getting it done.

Now, about the engineering manager who approved putting this contraption in the valley: What the heck were you thinking?! Such a dumb idea to have so much going on there, especially with the plastic parts and pressure. This is the same location that a coolant pipe leaks in my Audi V6 (though not an oil cooler situation). The only thing they should have put there was air manifold.

PS: also reminds me of the dumb spot where Toyota put the starter motor in their V8.

Bilko · Sep 28, 2022

The idea of placing the oil filler there makes sense to provide start lubrication. The problem is they designed a cheap plastic housing, if they had made something like the Dorman product this would be a non-issue. I am convinced the plastic goes brittle over time which accounts for the cracks induced by over-tightening the oil filter cap. Plus plastic has different expansion characteristics than Aluminum heads that may degrade the seals over time.

psimurda · Sep 28, 2022

Oh one thing I've realized the new Dorman926-959 oil housing is not compatible with OilFilters designed for Grand Cherokee 2011-2013. You need to buy one designed for Grand Cherokee 2014+

psimurda · Sep 28, 2022

Bilko said:
The idea of placing the oil filler there makes sense to provide start lubrication. The problem is they designed a cheap plastic housing, if they had made something like the Dorman product this would be a non-issue. I am convinced the plastic goes brittle over time which accounts for the cracks induced by over-tightening the oil filter cap. Plus plastic has different expansion characteristics than Aluminum heads that may degrade the seals over time.

Mine issue was that plastic cracked and started to leak coolant - I guess having over 100k miles with hot coolant and pressure the plastic cannot simply withstand that.

ColdCase · Sep 28, 2022

A lot of automakers are using plastics instead of metal, starting in earnest about 2000 more or less. Our 2006 Cheby's thermostat housing was made of plastic and as soon as I turned a bolt to replace it at about 10 years 60k miles it literally disintegrated into a dozen pieces... but then Cheby isn't expecting or wanting anyone to hold onto a car for more than 10 years. .

BigTizzie · Sep 29, 2022

Note to self: don't over tighten the oil cap.

psimurda · Sep 29, 2022

The oil cap says 18ft/lbs torque in service manual. I wasn't able to make that amount of torque using ratchet and don't screwing the plastic bolt - so I just hand tight it as much as possible.

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