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Discussion Starter · #1 ·
Well it has come to pass. Engine number 2 in my main PM has blown. It's the EXACT same problem that took out the first engine, though this time I caught it before it threw a rod.

The short story is it's got a #1 cylinder misfire which is compression related. It's not the coil, it's not the plug, and it's not electrical. I know this because a mechanical vacume gauge reads way low when the miss is occurring. That means the valve isn't seating/seating. The condition generally goes away at low load high rpm, and problems like rings, head gasket, etc wouldn't do that. So whatever the actual problem is, it's valve related.

Last January I had the EXACT same problem, which I ignored, and eventually the valve seat fell out of the head, crashed into the piston, and threw a rod. That little adventure cost me $5000. Ouch.

That occurred at 140,000 miles. Put in a junkyard engine with 40k, and now I'm at 268k. Do the math, and one engine blew at 140k, this one at 170k. What's weird is that my other 2014 PM is at 240k with none of the these problems. Dunno.

Regardless, I'm losing money every day I'm sitting so the plan is to not even bother with the head or the valve, and just replace the engine myself. In my driveway. LKQ sells engines all day long for $1600 - I found one with 20k on it right in my city. Replacing just the head is a $2200-2400 deal, even though the head itself is only $300 brand new from Chrysler with a 150k warranty. Nice. LKQ apparently sells an extended warranty for parts AND labor for like $100. I'll be investigating that one!

The good news is that I think this R&R is going to be fairly doable, even with my limited skills. I was able to get the AllData instructions. They show it as coming out the bottom, but the guy that replaced my first one did it in 17 hours and took it out from the front, which is how I'll do it. The other good news is that now I get a spare engine, which I can replace just the head on at my leisure. More good news is that I'll document it for future swappers. More good news is that I'll be able to determine if a 2012-2013 engine is identical. They cost 500-700 less than a 2014-2016.

The SUPER IMPORTANT MORAL TO THE STORY:
Those of you who have engines with less than 100k on them are LUCKY LUCKY LUCKY. You'll be due for plugs at 100k. Go ahead and bite the bullet and have a dealer do them, but make some kind of vague complaint about "running rough" or "misfires" and have him do a compression check while he's there. If your compression is good, good. If your compression is low on any one cylinder, then you have a WARRANTY claim and they will swap the head for free or reduced. If you wait till after 100k, you're screwed. He's already done a lot of expensive labor to change the plugs - a compression test is 30 extra minutes but might save you THOUSANDS.
 

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Discussion Starter · #2 ·
I should add that despite the above, I'm still quite happy with the PM. Between the two vans, we have 500,000 miles driven. Besides the two engines, I've done a buttload of oil changes, surprisingly few tires. Three wheel bearings. One starter. Plugs, coils, and transmission filters. One ball joint. One axle. One fan assembly.

But think of all the stuff I haven't done that would be commonplace on other vans. Alternators, water pumps, head gaskets, computers, A/C, fuel pumps, map sensors, oxygen sensors, brakes (500k and no brake jobs!), racks, blower fans, etc. All while getting 2-3mpg more than the Ford. For fun (at 2.09 per gallon) that's $9220 in fuel savings. So overall, I'm pretty happy.

Or maybe I'm just telling myself that.
 

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Did this engine idle a lot? If its a valve something is causing that valve to not seat and with 170K it should not be the guide. I might run an inspection camera in the plug hole to inspect the top of the piston. The low vacuum seems to point to an intake valve if it is a valve which is much less stressed than the exhaust normally. When you pull the head I expect you will post up and I appreciate that. You are doing our high mileage testing. I have done engine swops in the yard, in snow, in rain, no engine lift even. I hope to never do that again, but if I needed to get it back on the road....... I feel for ya. Your attitude is good for a bad situation.
 

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A leak down test will tell more than a compression test. You need more of a setup to do it than a compression test. If it has a loss of pressure you listen at intake, exhaust, and oil filler cap to see where you hear the noise. Low compression could be either valve. Non sealing exhaust valve usually has more of a fffttt noise to the exhaust note. Might not be able to see much with boroscope but worth a look if you have one.

Curious if it is carbon build up or maybe a run of cylinder heads with soft aluminum or something else screwy around the valve seats. ??? Any evidence of detonation? Is the quality of fuel you're running good?
 

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Discussion Starter · #6 ·
Good ideas fellas. It was me who postulated that this problem, which happened to me and to another guy on the board, was caused by excessive idling. I think we can rule that out. This engine, installed 170k ago in Feb of 2016, got idled a little bit at the tail of winter 16, but I didn't idle it at all this winter. Didn't need to, figured out other solutions to keep warm. It was just a wild guess anyway - so far as I've been able to find out there's no connection between idling and carbon, or idling and valve issues. As a pure highway van, I idle FAR less than the average soccer mom idling in the drive thru lane of a Starbucks anyway.

Nope, my guess is that when I get the head off I'll find that the valve seat has fallen out of the head and is loose on it's seat, just like the last engine. My mechanic partially ruled out a lifter or rocker issue because those would have constant symptoms. My misfire comes and goes, and is highly load dependent. And the vacume loss means it has to be intake valve related.

My mechanic did put a horoscope on it and didn't see anything noteworthy except two shiny spots on the top of the piston. This could be normal, or it could mean that it was drinking coolant. But the van wasn't loosing a drop of coolant, nor is it burning a drop of oil. When I have the head off, I can compare it to the other cylinders. It may turn out that the problem is something I haven't thought of, but since it's identical to the previous problem, and the pentastar has a history of valve seat issues (supposedly resolved by 2013) I have no choice but to assume that's the problem.

One remote possibility is the problem is magnified by the internal EGR design. The pentastar, like a CAT Acert, overlaps the valve timing to keep some exhaust gas in the chamber. This is why it doesn't have an EGR valve - it does it internally through cam timing. It's possible that if the cam wears, or the cam phasers get funky, it draws in too much exhaust and that carbons it or otherwise fouls it. Dunno. I'm clutching at straws.

In other news, went down to LQK today and bought an engine with 2000 (yes, 2000) miles on it for $1525. That's hard to beat. And it's a 2015. It gets kind of complicated, but as best I can figure ANY 2014-2016 pentastar will fit the PM except the oddball start/stop engine that came in the 200. This one comes out of a Journey. That's going to be the trickiest part of this swap - the engine I bought is supposedly fully dressed but until I pick it up tomorrow morning I won't know what fully dressed means, and I have to port my parts to it. I know the oil pans are PM specific, and I believe everything upstream of the MAF sensor is PM specific. But who knows what I'll find as I keep going. I'll report what I learn here.

It does bring up an interesting mental exercise though. Assume I drive 120k per year, assume I change my oil every 8k and the filter every 16k, and assume I do the plugs and coils every 100k. I ran numbers on this, and I come up with around $1300 in plugs, coils and labor and including 15 oil changes and 7.5 filter changes. Assuming my labor is worth nothing....I am pretty close to even by NEVER changing the oil or the plugs, and just changing the engine instead! Once a year simply change the engine and that's it.

I would never do that, but it's fun to think about. My other PM has 240k with no blown engines. And neither has ever burned a drop of oil. So the actual lowest cost thing to do would be to fix the problem by replacing the head when/if the problem happens. It's very possible it's easier to change the head by removing the engine to do it, especially since this time it's the rear head that's bad and that would a nightmare to swap out.

Brand new heads cost $325 from FCA, including the gasket. And since they had so many valve problems, the head comes with a 150k warrant (parts only). So maybe that's the answer - next time pull the engine, swap the head, and let FCA keep buying me heads. Another option would be to get a new or old head, and take it to someone who knows something and put a valve seat in it that won't fail.

This job is gonna suck, but I have high hopes to be back on the road by next week. I'd better be - money is going out but not coming in!
 
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Discussion Starter · #7 ·
A note on top tier: it's really moot since I'm all over the place, but I NEVER buy gas anywhere but Pilot, Love's, T/A or Sheetz or Wawa. Never. If I can't trust those places, I can't trust anybody.
 

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.....cut....

I would never do that, but it's fun to think about. My other PM has 240k with no blown engines. And neither has ever burned a drop of oil. So the actual lowest cost thing to do would be to fix the problem by replacing the head when/if the problem happens. It's very possible it's easier to change the head by removing the engine to do it, especially since this time it's the rear head that's bad and that would a nightmare to swap out.

....cut....
I've always thought the perfect engine for the PM would be an inline-6, which would make access to the rear head a non-issue.

Now that Mercedes is switching from V6s back to I-6s after many years, there are rumors Fiat may be looking at inline sixes also, although if they go through with it, it'll probably be many years before we see results.

If nothing else, it will be interesting to see if the revised Sprinter in 2018 gets the new 3.0L I-6 or if it retains the old V6.
 

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Brand new heads cost $325 from FCA, including the gasket. And since they had so many valve problems, the head comes with a 150k warrant (parts only). ...
Interesting that it's so cheap.
My money would be on small cracks developing in the head. This was one of my earlier concerns with the Pentastar's integrated exhaust manifold design. That's going to put a lot more heat stress on the head (aluminum) than a short exhaust port going directly to a conventional cast iron exhaust manifold. In the PM, the Pentastar spends much more time at high load than in a car or light truck. Could be cylinder 1 area doesn't cool as well as the other cylinders or has a weak spot in the design. It doesn't have to break completely, just let the valve seat loosen.

In the early days of the Ford Escort, the newly designed heads were cracking at very high rate. Eventually it was about impossible to find one in a junkyard that wasn't already welded back together. Ford decided to redesign it after 3 years.
 

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Discussion Starter · #10 ·
Carnut - that is a very good possibility. So far as I know, not many engines these days have the exhaust manifold cast directly into the head. On the other hand, you'd think they would be testing for that, and the vast majority of pentastars don't fail. We'll see when I get the head off.
 

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Discussion Starter · #11 ·
Update: Day one of the engine swap. I gotta say, right now I'm super optomistic. Me and a buddy put exactly 2 hours worth of work, and there is TONS of room to get this thing in and out. The exhaust is going to be easy. None of the accessories are going to need to come off the front of the motor. What I'm worried about is all the fiddly connectors and wiring. Getting it out is easy, getting it to go back together needs to be meticulous.

The other thing that worries me is all the parts swapping from motor to motor. When the junkyard pulls an engine, they just cut all the electrical/coolant lines and yank it, then undress the front drive. So every coil connector needs to come off, every injector harness needs swapped over. Again, this is all just nuts and bolts, but miss one and you are screwed. Luckily, we have the old motor, the new motor, and my other 2014 PM to compare it to.

Looking at the following pics, you'll see that once the radiator comes out, there's FEET of room to get at everything. The "bumper", meaning the cross piece at the front, simply bolts in, so that can come out if necessary. The hardest part will be figuring out a way to hook the motor to the cherry picker. I may make a plate, and the picker will just grab it from the side!

The secret to all this was taking out the radiator and fans as an assembly. Two coolant lines, AC lines, trans cooler lines, and the thing just lifts out with the surge tank still attached. As I say, two hours and we got it this far. I'm optimistic. Pics to follow.
 

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Discussion Starter · #12 ·
Update:
So far, I'm pretty optimistic. Me and a buddy worked exactly 2 hours on it today, and we got it this far. The radiator comes out as an assembly with the rad, fans, A/C condenser. Once that's out, there's TONs of room to get the engine out from the front. The crossmember can unbolt if needed. Plenty of room to get the engine out with all the front accessories still in place. The exhaust will be easy too.

The real work will be figuring out a way to hook the engine on the cherry picker. Then again, if the crossmember is out it could just come out on a floor jack. The other tough stuff will be unplugging all the wiring and sensors from the engine, and getting the harness clear. Then swapping all the front dress and wiring onto the new engine. Basically, this stuff is just nuts and bolts and connectors, but still - forget one or crush one connector and I'm screwed. We'll see.

More to come.
 

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I am amazed how open the access is to the engine. It looks like you have some great help too.

1965 Valiant? I had a '60 170 with 3 on the floor, loved that car! My folks had a 63 they drove cross country.
 

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Discussion Starter · #17 ·
It's actually FAR easier than I thought it was going to be, at least as far as access and space goes. Look at the front shot - you can see half the bell housing bolts and the starter staring you in the face. Other than the rear cat, there's only one or two bits of wiring on the back side of the motor, easily accessible from the bottom. Most likely, I will be taking the upper intake off before the engine comes out, and that's like 10 wiring connections right there.

Overall, this is WAY easier than any other FWD I've worked on. There's a large splash shield on the bottom on the passenger side - 4 bolts takes it off and it gives you access to most of the front of the engine. This is how the serpentine belt and tensioner, alternator, A/C compressor, and water pump would normally be accessed. Easy.

The whole front grill comes off in about a minute with torx screws. The radiator isn't even bolted in - it's retained by the top crossmember - 4 bolts. I took off 4 coolant lines on the engine, and pulled the entire radiator assembly out with the hoses still attached to the radiator.

I say that all now...ask me in a week when it won't run and I'm living on the street!
 
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My son was always out in my shop with me at that age! Great to have a kid who shares your interests! He's a professional longshoreman now and I hardly get to see him. He rebuilds smashed CONEX boxes and trailers now. They keep him REAL busy.
 
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