July 16

2004 Jeep Liberty Engine Replacement

Podcast2018, Jeep


Mark: Hi, it's Mark with Top Local. We're here with Mr Bernie Pawlik doing the Pawlik Automotive podcast this morning. How are you doing this morning Bernie?

Bernie: Doing very well Mark. 

Mark: So we're gonna talk about a Jeep Liberty this week, and you had to do an engine replacement. What was going on with this Jeep?

Bernie:The vehicle came to our shop.Towed in. Suddenly started running really rough and the owner had thought there was something wrong with the timing chain, so that's the process we took with the vehicle, looking at it.

Mark: And what tests did you do

Bernie: Well first of all, we went to see if we could start the engine, and of course scanned the vehicle for stored trouble codes, and we were able to start the engine. It ran really rough, but it did actually run and with the owners concern about the timing chain being a problem, we of course listened to see if there was a timing chain issue, and we couldn't hear any rattling or any noise of any sort. The engine was actually quite quiet other than it ran rough and there was a stored trouble code P0340 for camshaft position sensor circuit problems so we looked at things in that area.

Mark: And what did you find?

Bernie: Well we found, eventually, what we found was that the timing chain had broken but in the interim, it was an interesting diagnosis because the camshaft position sensor is located on the right cylinder bank and there isn't one on the left. A lot of newer engines would have two of them but this older engine just has one. And with that cam sensor code, it looked like it might be an electrical issue at first but we did verify it electrically as working. Eventually, we pulled the camshaft position sensor out, looked at it and we could see the camshaft itself was not rotating. So interesting that it would set that particular code with that description when it's not in fact a circuit problem at all, it's just that the sensor wasn't picking up a signal.

Mark: And why would the cam gear or the cam shaft not rotate?

Bernie: Well that's what we wondered and because I figured that this engine's actually running, it would be surprising that the cam would in fact not be turning. So we removed the valve cover and found that actually the timing chain itself was broken. Which explained a couple of things, the owner had said " I think it's the timing chain," and we ran it for a while, tried to verify it and couldn't hear a timing chain rattle because usually if there's a timing chain problem, there's always a noise, but finding a broken chain was a really unusual, an unusual find. 

Mark: So that's not something that you see very often, broken timing chain?

Bernie: No, as a matter of fact, I can't even think of the last time I ever saw one. I mean timing belts will break because they're rubber and they crack eventually and break, but a chain, it's a piece of metal, it's very, very, tough and very robust. A lot of time the guides will break, the chain will jump teeth, but to actually have a chain break, I can't even think of the last time I saw one. 

Mark: And so was there any other problems that were going on?

Bernie: Yeah, so, let's get into looking at a couple of photos here, here's our engine. This is the right cylinder bank with the valve cover off and you can actually see the timing chain. I've actually taken the timing chain piece out, this doesn't normally sit over here, it would be actually inside the engine. There's one piece of it, but this is why it was ... the rest of the chain is broken and stuck inside, but you can also see, there's supposed to be a rocker arm sitting here. It was actually lying loose, I just placed it here, but this rocker arm had popped off. So what we found had happened was the ... I'll just get the other photo here, the intake valve seat on cylinder number one had actually dropped out of position and this is a problem that happens on these engines. The valve seats will actually come loose and it jams the valve. It'll jam the valve in the open position, the piston comes up, smashes the valve and I think in this case, what happened is that this all happened probably in one foul swoop and broke the timing chain. So these arrows here, the red arrow ... Unfortunately this isn't the greatest picture; it's a smartphone picture, looking down at an intake port which is the valve's a couple of inches away from where the camera was taking the picture, but it's the best I could do with this camera. This is the intake value here, this piece where the red arrow is pointing. The yellow points to the valve seat, and the blue points to where the valve seat is supposed to sit. So you can see this thing here, this dark area here, is actually supposed to be up higher. So that kinda shows in a nutshell what happened with this engine. 

2004 Jeep Liberty Engine Replacement
2004 Jeep Liberty Engine Replacement

Mark: And which engine is this?

Bernie: Yeah, glad you asked, it’s a 3.7 litre V6. It's an overhead cam engine, gasoline. We do work on a lot of these with diesels for some odd reason, but yeah this is a gasoline motor.

Mark: And so the valve seat's dropped out, so that sounds like a pretty serious concern.

Bernie: It is and it does happen on these vehicles from time to time, it's actually one of the flaws of this engine and also the 4.7 litre V8 which is basically the same engine only with two extra cylinders. So this is a common problem with that line of engine. 

Mark: So that's pretty catastrophic and compounded kind of things. How did you repair this vehicle?

Bernie: So we ended up getting a good used engine for this vehicle. That was the cheapest way to go. Doing a full rebuild would be very expensive and far beyond the value of the vehicle. So we got a good used engine, and ran great after we put it in. 

Mark: And I guess was the piston compromised and the cylinder and all that? Is that why that it was gonna be more expensive?

Bernie: Well in order to repair it you'd have to do the timing chains, I mean at the very least, the timing chains, get the valve seats replaced, and you'd wanna do it on both cylinder banks because if one's dropped out, there's gonna be another one coming pretty soon. So in order to do all that work, it would far exceed the cost of even replacing with a used engine and at that point ... we never took the cylinder head off and looked at what damage happened to the piston. To break a timing chain, who knows what else has actually gone on inside the engine, so it would be pretty expensive to fix.

Mark: So normally, how reliable are Jeep Liberty's in this kind of timeframe?

Bernie: Well, obviously with this podcast, you've seen some of the worst stuff that can happen, the drop valve seats, and we've actually seen this happen on other Liberty's and not had this kind of catastrophic failure, so it doesn't always result in this particular problem. But timing chains do wear on these things. Valve seat drop out, that's probably the biggest issue. They're not the most reliable vehicles, there's a lot of little things that happen to them; it's not a Toyota. Toyota always seems to be the benchmark I go back to, but they are pretty decent vehicle for off-road but they have this little nit-picky things that happen. The engines are not the most fabulous. There's diesels, we talk a lot about those on our podcast, and they have their issues too. Personally, I'd go for the gas motor, just definitely more reliable than the diesel in spite of these problems. 

Mark: So there you go, if you have an older Jeep Liberty or a newer one, or any kind of Jeep, the guys to see in Vancouver are Pawlik Automotive. You can reach them at 604-327-7112.  Get your vehicles maintained regularly and they will last longer. You have to call to book ahead because they're busy or check out their website, pawlikautomotive.com We're on youtube, search for Pawlik Auto Repair, hundreds of videos on there showing repairs of all kinds of makes and models of vehicles. Hopefully you're enjoying our podcast. Thanks Bernie.

Bernie: Thanks Mark and thanks for watching. 

About the author 

Bernie Pawlik

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