March 20

2012 Jeep Wrangler Engine Replacement



Mark: Hi, it's Mark from Remarkable Speaking. I'm here with Mr. Bernie Pawlik, Pawlik Automotive in Vancouver. Vancouver's best auto service experience. 24 time winners, best auto repair in Vancouver, as voted by their customers. And we're talking cars. How you doing Bernie? 

Bernie: Doing very well. 

Mark: So today's victim is a 2012 Jeep Wrangler that had an engine issue. What was going on with this vehicle? 

Bernie: Yeah, so the vehicle came to our shop with a rough running engine. The owner had been to a couple other shops, but for some reason he really wanted to work with us on addressing his concerns. He'd been to one shop, they'd tested the compression and found one cylinder was bad.

He then went to a Chrysler dealer and they did a bunch of other repairs for some reason not heeding the compression test. Of course, you know, with all our shops, we all wanna do our own diagnostics. They did a bunch of work to try to fix the issue that was completely irrelevant. Spent a bunch of money there and then brought it to us for our professional opinion.

Mark: So what kind of testing and diagnosis did you do? 

Bernie: Well, so we verified the engine was running rough. We scanned the vehicle for codes, found misfires in couple of cylinders. We then did a full compression test on the engine, performed a leak down test, and determined that number three cylinder was completely, had zero compression.

And a couple other cylinders were really weak, low on compression as well. So the engine clearly needed at least a valve job, if not some more work. 

Mark: So what was the next step in the procedure? 

Bernie: Well, to actually take the heads off. So if we were gonna do a valve job, and a valve job is basically having the cylinder heads rebuilt, replacing valves that are burnt and, and whatever other issues.

It's a lot of work to take these apart. This is a dual overhead cam, V6 engine. It's fitted pretty tightly into the engine compartment. And you know, so to actually do the labour and the work involved is very expensive. So we priced out a couple of options, whether there's a used engine or a new engine, a rebuilt engine, and we came up with the best option being a rebuilt engine for the job. This is actually a Chrysler factory rebuilt, a Mopar rebuilt engine, really good warranty. And sort of met the best criteria.

Mark: So that's just an easier, less expensive and more reliable way of making sure the vehicle's gonna run well for a long time after you've done the repairs? 

Bernie: Exactly. So it's not necessarily less expensive right now, but over the long term. You know, I think it certainly will be. Once you do a valve job, it's several thousand, don't have the exact price, but probably half the price of doing the engine rebuild. But you've got an old engine with other things that can go wrong.

You know, there's a lot of risk of things, like the bottom end of the engine going bad or something, the bearings. And then you've gotta pull everything back out and do everything all over again. And so in the end you ended up spending way more money. And you know, the owner of this vehicle, he really loved this vehicle. 

Some people, their cars are just, yeah, gets me from A to B. If it costs this much money, I'm outta here. But this owner had customized, personalized the vehicle. He was really into it. So you know, it was a worthwhile investment for him to replace the engine.

Mark: And is it fair to say that if something is going wrong in the top end, you might have affected the bottom end, so that you're not gonna have as long a life in the entire engine?

Bernie: Sometimes that happens. It really depends on the engine. I mean, there's some engines where the bottom end is bulletproof. It'll last almost forever. You know, nothing will go wrong with it. I'm thinking like a Ford 6 litre diesel, where they just have oodles of problems with blowing head gaskets and just everything under the sun. But it's very rare for the bottom end to go on those engines. Not like it doesn't happen.

But in the bottom end, we're talking about the pistons, the connecting rods. Crank shaft. Crank shaft. Exactly. You know, those, those kind of things. But you know, the Jeep engines, to be honest, they're not the best engines on the planet. I mean, it's a 3.6 Chrysler. They, they're used in many, many vehicles and they're okay for reliability, but they've got a lot of issues.

Mark: So again, what sort of engine did you get for this repair? 

Bernie: Yeah, so the engine, it's a Mopar rebuilt engine, three year, a hundred thousand kilometre warranty, or is a hundred thousand mile, I can't remember, but it's a three year warranty. You know, fully covered labour, parts, everything, which is an awesome warranty for the customer. You spend a lot of money. It's nice to have something that's backed up really well. 

So we'll look at some pictures.

2012 Jeep Wrangler Engine Replacement

So here's the old engine here sitting on the stand. Got the timing cover removed, and first thing we noticed, so this is not even related to anything we found in our diagnostics, that there's a chunk of the timing chain guide rail here broken off. I hadn't actually processed this picture put an arrow in for some reason. I got the wrong picture here, but I'm just gonna move my mouse pointer around. 

There's supposed to be a piece of plastic that sits along here. It's a guide rail for the timing chain. So this piece is broken off and missing already. This one here, this is a guide rail on the other side. There's a lot more material here, or is that the tensioner side? Anyway, I think that's a tensioner side. The guide rail's up here on this one.

So on an overhead timing chain, you usually have a guide rail on one side and a rail on the other side that has a tensioner. And you can see this tensioner. There's a plunger here. It's pushed out almost all away. Whereas on the other side, this side here, this plunger's not pushed out too much.

So this timing chain was really, very close to being rattling and making a lot of noise. So again, this would've been another thing to replace while we removed the cylinder heads, adding more work. I mean, you have to take it off in some respects anyways. But these parts are all worn out, now they need to be replaced too. 

Mark: Would that timing chain issue, would that be part of the cause of the valve issues? 

Bernie: No, not right now, not yet. If the timing chain, say the guide rail were to have actually broken off and the timing chain jumped teeth, then it would cause some pretty serious issues, but not currently.

This is a bucket of, you can see it's full of oil and there's bits and pieces. This is that timing chain guide rail. Bits and pieces of it sitting in the bottom of this pan here. Again, I'm just moving my mouse pointer around if you're following this video. And if you're listening to it, well, there's broken plastic pieces.

2012 Jeep Wrangler Engine Replacement

Another close up view. This is that tensioner on the side with the guide rail. You can see again, I'm moving my mouse pointer here, this is where that piece of, that was in that plastic bucket. This is where that guide rail would've sat right here and you can see the tensioner. This pushed out quite a lot. Normally this would be probably sit back, moving my mouse pointer back, it'd probably sit back, a quarter of an inch, half an inch more. So it's doing its job, but it's very much at the end of its travel. 

2012 Jeep Wrangler Engine Replacement

And finally this is our replacement engine. This is sort of a view of the bottom end of the engine before the oil pan is installed. This is the oil pickup tube that sits in the bottom of the engine, the engine oil pump. And you know, oil pumps, are a very sophisticated device these days. It used to be they just had a couple of gears in them and they suck the oil up and pump it through the engine.

2012 Jeep Wrangler Engine Replacement

But now the pressure can be varied electronically so that you're not wasting energy pumping oil through an engine that doesn't need quite as much oil flow, or maybe it needs a little more. So again, these are much more sophisticated piece than you normally get in the past. And just on the ground here below us is the oil pan waiting to be installed. 

And finally, this is our Jeep. Sort of an aerial view from the mezzanine of my shop, with the engine sitting on the stand, waiting to be hooked up and put into the vehicle.

2012 Jeep Wrangler Engine Replacement

Mark: Were there any other items that needed to be replaced with the engine? 

Bernie: Yeah, so when you pull an engine out, this is a standard transmission. The clutch, of course needs to be inspected. And we found the clutch was worn out. Not completely cuz it drove in okay. But the clutch did not have much life left in it. So we replaced the clutch. There's no extra labour charges to do it at this time. It's a good time to do it. 

Clutch, by the way, is not cheap for this vehicle surprisingly. I don't know why the actual parts are very expensive, but nonetheless, we replaced the clutch. There's no extra labour. We also found the starter motor for some reason had a problem. So we replaced that. And the clutch slave cylinder, another item that normally would've been okay when we went to, you know, push the plunger back in, it's a hydraulic piece, was leaking fluid, so we replaced that too. So again, a lot of items, no extra charge for the labour. But it does add to the parts bill. And on the engine there's bits and pieces, gaskets and fluids and things like that, that are just normal part of the job. 

Mark: That seems like a lot of stuff going wrong for a 10 year old vehicle. 

Bernie: Yeah, you never know. You know, the thing was well used. But these Jeep engines, that 3.6, I'd just say just Jeep, but the 3.6 litre engines, they have issues with cracking cylinder heads, timing chain issues. There's a lot of things that happen to these. So they're not, as I said earlier, they're not the most reliable engines on the planet but if you like the Jeep, this is what you're kind of stuck with. You know, that's the engine, that's the vehicle it comes with, you know, changing it to something else really isn't an option.

Mark: So other than that, how are this vintage of Jeep Wranglers for reliability? 

Bernie: Yeah, they're pretty good. I mean, they're kind of the same as Wranglers have been all along. You know, if you look at older ones, perhaps they're a little more, you know, some of 'em are a little slightly more reliable engines, but, you know, they're a decent vehicle. But as I say, you know, the engine is one of the weaker spots on the vehicle. 

Mark: If you're looking for service for your Jeep in Vancouver, come see the experts at Pawlik Automotive. You can book online at They will call you back once you book and find out what's going on. Get ready for your appointment or you can call them to book (604) 327-7112. Pawlik Automotive in Vancouver, BC, Canada, and thank you so much for watching and listening. We really appreciate it. Thank you, Bernie. 

Bernie: Thank you, Mark. Thanks for watching.

About the author 

Bernie Pawlik

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