Read this before you swap...

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Ok, what is up with new hemi valve seats falling out of the heads???? My buddy has a 300C 5.7 hemi. Has about 65K on it and it dropped a valve seat about 2 months ago. Drove it, stopped for gas got back in and started it, motor made an awful noise and power was way down. Took it into the dealership and they mechanic knew what happened even before the story was over. And the kicker: The warranty doesn't cover it because it is an "unlubricated part". What the H? So $1600 later (and a 90 day warranty on the new head) he is back on the road with a car that he doesnt really trust anymore as the mechanic told him "it can happen at any time". So, he calls me a few minutes ago after driving about 20 miles..it happened again! He is hoping its the warranty head or else he is out another $1600 and will unload the car after its fixed. He loves the car, but hates the valve seats! Its all over the place on the internet, but the consumer reports says its a good car. look here http://dodgeforum.com/forum/3rd-gen-ram-tech/197085-hemi-valve-problem.html and other places...Why would they just fall out, could you do something to the new heads seats before you install them?

Since when is a 'valve seat' a separate part of the head? It sounds like a BS answer to me; one which I'd let some lawyer chew on. AFAIK the head IS a lubricated part and the seat is integral to the head assembly, even if it is pressed in. If its not being lubricated then its the fault of the manufacturer for not designing it to get lubrication. I smell a class action lawsuit coming real fast...you might hate lawyers but it's BS answers from car makers like this, trying to skirt their responsibility that keeps lawyers in business. That's a manufacturers defect; pure and simple, insufficient interference fit between the seat and head to retain the part under normal operating conditions or a failure of the metal to retain its shape. Chrysler has had a rash of this - it was happening a LOT on their 426 hemi heads sold in the not-too-distant past.
 
Chrysler is also having a similar problem with the new 3.6L engines, except the seats aren't pressed in all the way from the factory. 10 or 15k miles later as the closing valve pounds the seat further and further into the head, the seat gets cocked so the valve can't seal anymore.
 
The "Pentastar" motor is supposed to be the flag ship of the new Chrysler, you gotta be kidding! "Not pressed in enough" gets past umpteen QC precedures? Unreal.....Are the heads procured out of Saltillo, Mexico?
 
i have a cammed 04 dodge hemi ram i spray a 225 shot on it and i know it has a 1000 plus passes on spray with no problems at all to motor, plus i drive this everyday,

heres a vid
[ame="http://www.youtube.com/watch?v=f3kSgEar5sY"]Podunk white hemi 7.430 - YouTube[/ame]
 
Update: Buddies 300C hemi motor is toast. OTHER head lost an exhaust seat, valve hung open, piston hit it (big crescent on piston crown) and broke head off. Destroyed the cylinder. $9300 dealer motor replacement or aftermarket rebuild $3500....Day after its fixed its getting sold. That is some tough luck, eh? I told him bring 3rd party waffling warranty company (not covered.."any scenario you tell me, I can defend" said the warranty agent, the moxy!!!) to small claims court big time, this is ridiculous....He's so pissed he'd jumping the new hemi ship and getting his 67 Mustang back on the road with EFI...Bummer.
 
Since when is a 'valve seat' a separate part of the head? It sounds like a BS answer to me; one which I'd let some lawyer chew on. AFAIK the head IS a lubricated part and the seat is integral to the head assembly, even if it is pressed in. If its not being lubricated then its the fault of the manufacturer for not designing it to get lubrication. I smell a class action lawsuit coming real fast...you might hate lawyers but it's BS answers from car makers like this, trying to skirt their responsibility that keeps lawyers in business. That's a manufacturers defect; pure and simple, insufficient interference fit between the seat and head to retain the part under normal operating conditions or a failure of the metal to retain its shape. Chrysler has had a rash of this - it was happening a LOT on their 426 hemi heads sold in the not-too-distant past.

I agree..it's their design, their product..."bumper to bumper warranty" or 100,000 on driveline.....there is no maintenance for this in the manual....so I'd be spending My $$$$ on a class action law suit
 
blah blah blah this has come up before. I call bs I need pictures. I've yet to see actual proof and have 3 hemis apart in my garage 2 high mileage(1 busted rod one spun bearings) 1 was 10000 kms on it and have yet to see any evidence of valve seats going anywhere.

not sure if this is going to post the right guy. I have a heavy I pulled apart and will gladly send you pictures if you give me a number to send them to this blew me away when I saw it I've never even heard of a valve seat falling out unless it was a bad rebuild this was factory. But what makes this one special is that 6 intake valve seats or hang out stopping the valves from closing. The seat is completely lose from the head on 3 cylinders on each side. one exhaust valve has a section broken out of it that has done damage to the head when the piece was beaten up by the piston. the thing that puzzles me does that all 6 of them struck the top of the piston but only appear to have hit once or twice. this means all 6 fell out at the same time. exhaust seat have gone out before.
 
not sure if this is going to post the right guy. I have a heavy I pulled apart and will gladly send you pictures if you give me a number to send them to this blew me away when I saw it I've never even heard of a valve seat falling out unless it was a bad rebuild this was factory. But what makes this one special is that 6 intake valve seats or hang out stopping the valves from closing. The seat is completely lose from the head on 3 cylinders on each side. one exhaust valve has a section broken out of it that has done damage to the head when the piece was beaten up by the piston. the thing that puzzles me does that all 6 of them struck the top of the piston but only appear to have hit once or twice. this means all 6 fell out at the same time. exhaust seat have gone out before.

Good info to share but I think this post is about 3 years old.
 
Old post for sure, from what I have read this was a more significant problem with the early motors, but if you do overheat them then the valve seats are very likely to drop out as you have two different metals with different expansion rates that are only press fitted together. Basically keep your cooling system properly maintained and stop driving it at the first sign f trouble just like you would if the oil light came on.
 
I don't like the idea of peening the edges. The stress and pressure from peening the valve seats may also make the seats "out of round". I ran the head lines in an engine plant and know the tolerances. The roundness for the valve seats is held to 13 microns ( or 0.013 mm). This is a VERY TIGHT tolerance to hold and we had the machine operators for the valve seats check them every 10 - 15 minutes. 1 mm is equal to .040", so take .040" and cut it into 1000 equal pieces and then take 30 of those. It is thinner than the diameter of your hair. Peening them could throw them out of roundness unless you remachine the seats afterwards.

The only reason that the seats would fall out is if they did not get their press fit correct which is determined by the hole size. The hole size tolerance is so tight, you cannot just use a drill and keep it in spec., you have to use a reamer which can hold a tighter tolerance. This is also monitored in the machining line with load cells to monitor the press in load for the seats. They set the limits of the load cells by testing sample parts to determine the acceptable load for a good part. If it allows a bad (not enough press fit/interference) part through, they did not properly establish their limits, or someone opened up the limits on the press in operation for the load cells.

I was involved in a change to the metal that the seats were made of and had to test the new parts to make sure that the limits were acceptable for the new parts vs the old ones. There was a difference in changing the hardness for the seats and we had to establish new load limits.

Bottom line, if they had proper control of their process like they are supposed to, this wouldn't happen. It is the responsibility of the head machining plant, which in this case is in Mexico for the 5.7 L engine, to keep their process under control.

The engine plant that I worked in literally made 1 million heads per year and we never had a problem with the seats falling out.

Truth,and a great post Karl..
 
That tick can sometimes be attributed to cracked exhaust studs as well, though it will probably be noticeably louder. The earlier studs had an issue with this, and my 06 one even did. One if not two studs broke off right at the head. I got lucky though, that was the first time my screw extractors actually worked like they were supposed to, lol.

what studs? I have bolts. exhaust to heads..
 
Old post for sure, from what I have read this was a more significant problem with the early motors, but if you do overheat them then the valve seats are very likely to drop out as you have two different metals with different expansion rates that are only press fitted together. Basically keep your cooling system properly maintained and stop driving it at the first sign f trouble just like you would if the oil light came on.
Years back looking for a 5.7 for a Magnum everything we found under $1000 had the valves dropped in it, those under $600 were if not window'd then f'd short blocks. An $1800 used motor in a car that mayn'tve been worth $7000 didn't make sense. JY bought the car for more than he had at auction, so it all worked out.

Things like this seem to be how these newer motors fail anymore- most of what I've seen has made it look like it's the same old, same old with neglected stuff giving trouble and that's just how they do.
 
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