Mechanic: Pentastar Oil Cooler · 3:41am Feb 28th, 2022
Happy late February, y’all! This is a mechanic blog, so y’all know what to do.
I’m gonna do two things a bit differently here. For starters, I’m just going to tell you right up front about what the problem is, what the failed component does, and how it’s diagnosed. Bear with me as we get a quick lesson in one aspect of modern oil technology!
First off, we’ve got to talk about our humble oil filter. The one y’all are probably most familiar with are little spin-on cans that typically go on the bottom of the engine. Inside they’ve got a filter media which is folded into a fan pattern to have the biggest surface area possible, and it’s supposed to catch all the little bits of metal or whatever other contaminants in the oil and trap them so they can’t hurt the engine. Some of them have other technologies inside, like anti-drainback valves if they’re not oriented thread-side up.
[Cars didn’t always have oil filters; IIRC in the US they only started being standard equipment on engines in the fifties. There were ways that you could add an oil filter to a car that didn’t have one, and if memory serves one kind used a roll of toilet paper as the filter media.]
In the last couple decades, automakers have been using more and more cannister-style oil filters, where you just get the media and put it in a can of some sort on the car. I don’t know why this is; it doesn’t seem like it would be cheaper to construct at the factory (since you’ve got to make a cannister instead of a threaded pipe and a machined flat surface). The first cars I recall seeing them on had European engines, so it could be that the EU doesn’t like traditional oil filters. If that’s the case, they might be doing it to unify their engines across the Atlantic. Or it could be a packaging issue; the Acadia, Enclave, Traverse and whatever else is in that family has a very difficult to reach spin-on oil filter. Maybe somebody who wasn’t GM thought it would be easier to fit an engine in new platforms if the oil filter was tucked into a housing on the engine rather than sticking out somewhere, who knows.
Another thing that’s more common on modern cars that used to only be on race cars is engine oil coolers. I don’t know specifically why they’re using them over the last couple decades, although if I had to guess, I’d say since they’re also using the oil to set the cam timing or even control one set of valves on the Fiat Multi-Air engine, having it get to a steady temperature and stay there as fast as possible really helps with engine control.
GM used to put the oil coolers in their trucks in the radiators, where they were attached with a set of (usually leaky) hoses, and after reading a Craigslist ad some years ago, we started calling them “oil relocator lines.”* Did I mention they leaked a lot?
Really, all that matters is that the oil cooler is somewhere you can get coolant to. Chrysler, on their Pentastar (3.6L) engine had the brilliant idea to make the oil filter housing (it’s a cannister-style) and oil cooler all one assembly. They had the further brilliant idea to put the whole thing in the valley, which is the space between the cylinder heads on a V engine. In the old days, the intake manifold would sit there, but intakes are designed differently these days, and that’s basically wasted space down there.
That plastic and aluminum part has a high propensity to springing leaks, which leads us to the final two facts:
1. The Pentastar is in a lot of Chrysler vehicles. Jeep Cherokees, Jeep Wranglers, Dodge Caravans, Chrysler Town and Countries, Chrysler Pacificas, Chrysler 200s, Chrysler 300s, Dodge Challengers, Dodge Chargers, Rams, ProMaster vans, and probably some other stuff I didn’t think about. Basically if it’s a mid- or full-size car, truck, van, or SUV, the Pentastar is probably an engine option in it . . . or the only engine available in it.
2. The valley is big and deep and can hold a lot of oil, and it’s hard to see in it with the intake and various air boxes on it.
Some people read my mechanic blog posts and might think that our shop is always dysfunctional, or everything is a disaster to repair or diagnose. That’s not always the case (well, it’s usually dysfunctional), but honestly the mundane stuff isn’t really worth blogging about. You probably don’t want to read about replacing a set of tires on a car because the old ones were worn out, or doing a standard brake job, or putting spark plugs in a EcoTech engine as a standard tune-up.
So far this month we’ve done three oil cooler assemblies on Chrysler Stellantis products: a Jeep something, a ProMaster, and a Ram 1500.
This is what a Ram 1500 looks like, more or less:
Source
For whatever reason, I didn’t think to take a picture of the actual truck
Here’s what the oil cooler/filter housing looks like:
There’s one coolant hose that goes in the back (top in the picture) which is the hardest thing to remove when you’re doing the job. One or two sensors, depending on application (this one has two), the aluminum block which is the cooler itself, and the angled thing at the bottom of the pic is the filter housing. It would face up on the actual engine.
On the bottom of the part (which you can’t see) there are a number of passages with o-rings to let coolant and oil in and out.
Here’s what it looks like under the hood of a Ram 1500 with a Pentastar motor:
I didn’t think to take pictures of what it looks like with the intake hoses off or the inlet resonator off, but once you’ve got those off and the upper intake, too, you’ll get to the lower intake. That’s where the fuel injectors go on this engine, and depending on application, the fuel line quick-connect is the second-hardest thing to remove.
The round cap with the hex on top of it is the lid to the oil filter housing. You’ll also note where the ignition coils are (you can see the wires running out of the valley and up to them); the ones on the left side of the engine (right side of the picture) are underneath the upper intake manifold, and now would have been a good time to replace those spark plugs.
The lower intake is off, and now you can see where the oil cooler/filter housing sits in the valley. Installation is the reverse of removal.
I have one last picture of the engine, which illustrates how much oil this thing can hold before it starts leaking out:
This is after I sucked the oil (and coolant that spilled when the cooler was removed) out of the valley. You’ll notice that the knock sensor (black round electrical thing with a Torx bolt in it) was underwater, and you can see the staining on the heat-wrap on its wires, too. You can also see the staining on the block . . . on rear-wheel drive applications, going up hills spills some of the oil out onto the transmission bellhousing, where it runs on the ground and is noticed. On front-wheel drive applications, the car has to tip pretty far to the left before oil starts spilling out, or the valley has to fill all the way up before there’s an obvious leak.
So there you go! A routine diagnosis and repair of a high-failure item on a common engine!
*in the ad in question, the seller had listed all the parts of the truck that had been replaced, including the ‘oil relocator lines’ (oil cooler lines). On those trucks, they were such a high failure item, Dorman made a set, and most auto parts stores stocked them.
More relaxing:
derpicdn.net/img/view/2020/3/29/2309012.png
Source
So how are you preparing for the inevitable influx of electric vehicles? Thanks to a certain state out west and it’s twin in the east we will be getting them before the infrastructure is there for them.
Historical Note
AutoZone started as Auto Shack. Radio Shack sued their ass for infringing on their precious copyrighted name. So, Auto Shack changed their name.
Guess which one filed for Chapter 11 bankruptcy in 2015.
Surprisingly, the corporation that bought them kept the brand name going in the USA & Latin America
5640256
I remember an episode of South Park calling Toyota's product the Pious & showing it as producing clouds of smug.
"Engineers!" has become increasingly a swear word, in all matters mechanical. If they made the guys swap off, one year in the company designing, one year doing dealership work, back and forth, I suspect many more parts would be "Twist this, pull the unit out, put the new unit in, twist to lock. Next!"
5640256
Depends on the manufacturer. Tesla doesn't like their cars being repaired by third parties; they'd rather do what consumer electronics manufacturers do, and just give you a brand new car while your old one is shipped back to their factory for refurbishment or recycling.
"Happy late February, y’all!"
Aye, following your lead, I finally took the hat off. :D
What's the thing with Stellantis? And was "#sneaky oil leaks" supposed to be in the tags twice?
And thanks, as usual, for the interesting information and cute ponies. :)
5640256
"before the infrastructure is there for them"
Including, from what I recall hearing, the power grid. I mean, it's not as if we have a bunch of spare grid capacity that's just been built and maintained because the utilities thought it'd be fun. Even if, say, there was some big program to add charging points all over the place, those charging points still end up putting the load on the grid (rather than, you know, conjuring the electricity from thin air, any more than food poofs into existence in the back rooms of grocery stores), and if there are a lot of new electric vehicles being added at once...
That looks so close to what I had to deal with a year and a half ago on a 2006 VW Passat.
I tried so hard to do it myself, only to break everything worse than when I started. (I somehow bent the fuel rails.)
Turned a $500 repair quote after discount into a $2000 repair quote on a car I bought for $3600. That's not including the $500 in told and parts I bought to fix it myself.
Got rid of that car in less than a year, because every single thing I touched needed a $200 tool to fix. Fun car to drive, comfortable, but absolute hell to fix.
https://youtu.be/my4osofojRk
Timing my first car from scratch was easier, cheaper, and faster than that project. Never buying a German car again. Don't do it unless you have a good mechanic.
Though, when I did it, it's upside down in that wv compared to the Pentastar, oil filter in the bottom. I had to fix it for a vacuum leak so it would pass safety.
It wasn't worth it.
Lots of things these days are sunk cost fallacy designs, where theyre only continued because even though doing a total rebuild of the production facilities, given they build totally new lines anyway, is less of a hit that the effect on their ego and philosophy?
Theyve fought for a centuary to keep electric down because oil cant compete and now theyre on parralel hybrids and pure electric only to try and keep the carcass warm a little longer?
You should turn the engine upside down and give it a good shake. That would get the oil out.
5640299
It isn't even overall capacity. The power grid works sort of like the branches on a tree: big trunk, smaller branches, little twigs, then the individual leaves. You have substations or transformers at each step, right down to the power coming off the lines into your house. Each one of those has a maximum capacity, and they don't build in a ton of extra slack. The UK is already requiring that car chargers be connected to smart switches controlled by the utility company due to overloads, and they're nowhere near 100% adoption of electric cars.
5640299
Well, they're sneaky.
It seems a bit counterintuitive to place a 'cooler' in such a hot place.
Also, that CGI Dodge Ram is an SRT-10!
It was a Ram with the 500hp 8.3L from the Dodge Viper in it. I had one, and it was a ball to drive!
5640325
Yeeeep.
5640326
That is what I thought might be the case, yes. :D
5640256
The real trick is what information the automakers are going to give us. I won’t get into the laws (I’m no lawyer, and it gets weird), but Tesla pretty much won’t release any service information to the aftermarket.
We’ve already done work on hybrid vehicles from established automakers (Ford, GM, Toyota, etc.); there are some new tools we’d need to have, but then that’s always the case.
5640262
Which is a shame; I’d love to get parts from AutoShack. That sounds like a store that would have reputable parts
5640263
Heh, that’s brilliant.
5640264
I did work with one guy at Firestone who was going into auto engineering, so of course we all showed him everything stupid on the cars we were working on. Twist-lock is nice except when it gets dirty, then it can be horrible. New Beetle headlights have a clever system to pop themselves out so you can change a bulb, it works great unless it has dirt in it (which happens about three minutes after the car leaves the assembly line).
Heck, that fuel line that’s one of the more difficult things to remove on the Ram is a plastic quick-connect. Snaps together fast, and if you can get it rotated to a position where you can squeeze it, it also comes out.
5641307 Cotter pins for the "it won't come out until you want it to" One of the wonderful things about farm equipment.
5640290
I expect at some point they’re going to get sued for that and lose; I’m surprised it hasn’t happened yet. But then I don’t know the exact ins and outs of the Right to Repair laws. Could be that some states will ban them from being sold or operated if they don’t make their repair information available.
Note that it doesn’t have to be cheap; we pay thousands for a subscription to GM’s diagnostic and programming site, and if we want to access certain other features, we need a valid locksmith registration, and/or pay additional per-vehicle fees. So if I bought a late-model GM car and wanted to have full access to the programming and diagnostics for it (from GM) it’d probably cost me a locksmith registration (whatever that costs), a several thousand dollar scan tool, two thousand/year subscription fee, and an additional hundred or so dollars per VIN I registered.
5640299
That’s Fiat-Chrysler and PSA group’s new corporate brand name. Stellantis owns Abarth, Alfa Romeo, Chrysler, Citroën, Dodge, DS, Fiat, Fiat Professional, Jeep, Lancia, Maserati, Opel, Peugeot, Ram and Vauxhall.
No, but it’s appropriate
That is a problem, although not an unsolvable one. And it’s never stopped other technological innovations before; cell phones started becoming popular before there was a good cell phone network in place; internal combustion cars pre-dated gasoline service stations. Apparently, back in the day, drug stores sold gasoline in cans by the gallon.
I would assume that like most technological advancements, a full implementation of electric cars would come on over decades, and that would give time to build capacity in the network, and maybe find some other solutions. And I think that with how most people use electric cars (short trips mostly, just like they use gas cars), there wouldn’t necessarily be as huge a burden as charging up 300 million cars from dead to full every night, y’know?
Heck, here’s a question, how much power is being used in the US to charge laptops, cell phones, cordless power tools, etc., which wasn’t even a thing that the grid had to deal with thirty years ago? Each device is pretty small, but there are a whole lot of them.
5640302
I’m sorry
I did an intake manifold gasket on one of those not long ago, so I feel your pain.
There are times when the mechanic would have been cheaper. In truth, that’s one of the reasons I paid a pro to replace my roof. Can I replace a roof? Probably. But it would take forever, and probably not be done right, and I’d have to buy tools I don’t have. The guy I hired did it in three days, fixed other stuff I didn’t know was broken while he was up there, and I’m way more confident in his job than what I could have done.
Yeah, that’s another problem with some projects. I have a small collection of VW only tools; we don’t see enough of them for me to have had to make a big investment yet. And in all honestly, I probably wouldn’t for a VW, not unless I could use them for other stuff or we start seeing a lot of them.
Mind you, my small investment in VW-specific tools in also on the back of tens of thousands of dollars of more general tools.
5640306
Some of that does depend on the automaker; they’ve all got different philosophies when it comes to that. To be fair, some of the development costs are stupid expensive and they’ve got to earn their money back if they can.
I think a lot of automakers don’t really care what they sell as long as it makes them money. Some of them fought against change while others just adapted to it. But it’s hard to say, really.
5640307
That’s an idea. Might be easier to flip the whole car over, rather than unbolt the engine to turn it over.
5640326
They are sneaky.
5640409
Well, it ‘cools’ it to the same temp as the engine coolant, which of course has a huge radiator up front to dump heat. That’s a more practical way of doing it than having a separate unit for everything up front.
Ford came close on some of their diesels; they’ve got a two radiators up front (one for the engine coolant, one for a separate fuel cooling system), a transmission cooler, an intercooler (for the turbo) and an AC condenser; they might also have a power steering cooler up there, I don’t remember.
It is! I never have driven a SRT-10, although I did drive one Dodge work truck with the V-10. On my test drive, it averaged three miles per gallon.
5641308
The thing I hate about cotter pins is when they rust in the hole and then you’ve got to drill them out in order to put in new cotter pins when you’re done working.
5641324
Oof, mine averaged between 10-12 mpg but required premium fuel only and had a 34 gallon tank. I called it smiles per gallon as she was a Saturn V rocket on the road and as loud as the end of the world.
5641320
Or just drop a match in there. That would deal with the excess oil.
5641337
Oil’s not as flammable as you’d think. It’s really hard to get it to catch on fire without a wick.
Granted, you can if you try hard enough.
5641333
I think it’s normal average was higher (probably 8 or 9 mpg), but after the repairs we did, on a short, cold drive, while the computer was re-learning optimum performance, it did not do well.
I’ve always said that those big v10 engines are for when you want diesel torque and jet engine fuel economy.
And I shouldn’t pick on it too much; my old Chevy truck got 10mpg with an inline six. Granted, it’d get that same 10mpg no matter what, so while it was terrible when you were driving the truck empty, it was pretty good when you were towing.
5641338
I believe in you.
5641342
I did start a fire boiling water one time, so I believe in me, too.
5641313
Ah, thanks.
:D
:)
Sure, sure, expanding capacity would solve that issue -- but that, as you say, takes time. It'd be part of a thorough and well-thought-out plan for such a transition to electric vehicles.
...And let's just say I don't have much confidence in current American governments to deploy this as a thorough and well-thought-out plan in support the public good. Rather than something more along the lines of "BUZZWORD GOOD! SAY BUZZWORD, GET VOTES! SAY RIGHT BUZZWORD, GET LOTS BRIBE MONEY!".
...It is possible I'm somewhat cynical about our "leaders", yes, just a bit.
5641637
Or just overall electric usage for whatever reason. But it does take time, and a forward-thinking electric utility.
Yeah, I’m right there with you. Some of it might come down to state governments rather than Federal. And there are other potential routes, such as home solar to charge your car, or even an option that electric utilities could offer . . . mine lets me pay a little bit extra to get more of my electricity from renewables. I don’t know if it actually makes much difference (they probably only get so much from renewables, so if I pay extra to get 25% of my electricity from renewable sources, does that mean someone else now gets none of theirs from renewables?).
I don’t blame you, honestly.
5650125
Right.
Aye, there are things that could be done.
"I don’t know if it actually makes much difference (they probably only get so much from renewables, so if I pay extra to get 25% of my electricity from renewable sources, does that mean someone else now gets none of theirs from renewables?)."
I assume the idea is that, if they're making enough more money from it, they'll be incentivized to build more renewable capacity. But without that, yeah, as far as I can see it'd just be charging more for doing the same thing they'd do anyway (that is, going from, say, A and B each paying one dollar for a mix of 5 watts renewable and 5 watts nonrenewable to B still paying a dollar for ten watts, now ostensibly completely nonrenewable, while A pays a dollar fifty for ten watts, now all ostensibly renewable... but it's not like the electrons in the grid are tagged as to their source, so the actual power received by A might still be mostly coming from a seventy-year-old coal plant while B lives within sight of a wind farm).
Yeah, does... much of anyone, outside the halls of power, think the American government is really in a good situation these days, or has been for years? Obviously, people disagree quite strongly on the details of the dysfunction, but who's going to look at the current state of affairs and say "Yes, this seems to be ticking along nicely"?
5651519
I don’t know if anyone in the halls of power thinks it’s going well.
One problem we’ve had in Michigan is that parts of our state constitution were passed with the idea that we couldn’t trust the state government, so even things that both sides agree they want (and the population at large) sometimes can’t be gotten without jumping through a lot of hoops. Like, I can’t remember the exact details, but a few years back there was a bill to fix the roads, but because it involved changing how fuel tax was distributed, there had to be a constitutional amendment or something.
5654901
Eh, I'm pretty sure at least some of them, likely at least most, are that deluded. Though, yes, some others might just be lying through their teeth to everyone else while trying to pack as large a personal golden parachute as they can.
Oh, sorry about the difficulty there.
5655439
On the plus side, actual bad legislation has trouble getting passed, too, for the same reason.
5655464
Aye, that does seem an advantage.