broken valve seat

To begin with, broken valve seats are expensive.

How would you feel if you had to repair them again….in a week?

Exactly!

This is a partial list of vehicles and engines we have seen with this problem:

  • Ford Escort 1.9 SOHC, Engine VIN Code J, 1986 thru 1996
  • Ford Escort 2.0 SOHC, Engine VIN Code P, 1997 thru 2005
  • Ford Focus 2.0 SOHC, Engine VIN Code P, 1997 thru 2005
  • Jeep Cherokee 3.7 SOHC, Engine VIN Code K, 2002 thru 2010
  • Jeep Liberty 3.7 SOHC, Engine VIN Code K, 2002 thru 2010
  • Jeep Cherokee 4.7 SOHC, Engine VIN Code J,N,P 2002 thru 2009
  • Dodge Dakota 3.7 SOHC, Engine VIN Code K, 2002 thru 2010
  • Dodge Durango 3.7 SOHC, Engine VIN Code K, 2002 thru 2010
  • Dodge Pick Up 5.7 Hemi, Engine VIN Code D, T, Z, 2003 thru 2009
  • Dodge Ram Van 5.7 Hemi, Engine VIN Code D, T, Z, 2003 thru 2009
  • Dodge Ram Wagon 5.7 Hemi, Engine VIN Code D, T, Z, 2003 thru 2009
  • Dodge Charger 5.7 Hemi, Engine VIN Code H, 2005 thru 2009
  • Dodge Magnum 5.7 Hemi, Engine VIN Code H, 2005 thru 2009
  • Dodge Charger SRT 6.1 Hemi, Engine VIN Code W, 2005 thru 2009
  • Dodge Magnum SRT 6.1 Hemi, Engine VIN Code W, 2005 thru 2009
  • Dodge Viper SRT 6.1 Hemi, Engine VIN Code W, 2005 thru 2009

The following is an excerpt from an industry tech bulletin:

“Repeat engine failure has been reported shortly after first engine start on engines that had failed due to valve seat breakage. In these instances the original failure had been in the number one cylinder at the intake seat [but can occur in any] location. Subsequent engine failures in these instances has been traced back to debris that remained in either the intake or exhaust manifold. The debris found that re-entered the combustion chamber included particles of valve seat, piston/ring material from the original failure.”

When a valve job is to be performed, it may be common procedure for the technician to just pull the intake and exhaust manifolds back to provide just enough room to get Valve Seatthe cylinder head off of the engine. Doing so does not allow ample ability to clean either manifold. When a valve seat comes out of its counter-bore it shatters into many pieces from impact. Those pieces from the valve seat may enter the intake and/or exhaust manifolds as the result of normal air turbulence. The cylinder head for this engine originally uses PM (powder metal technology) valve seats with an approximate depth of .286″ (7.264 MM). When these seats shatter, many pieces result.

For the reasons stated above, it is imperative that both manifolds be removed from the engine compartment and all debris removed. Failure to clean out the intake and exhaust manifolds could cause a repeat engine failure. One aftermarket PM valve seat manufacturer has found using different seat materials; processes and designs that have resulted in improved seat insert retention in the cylinder head for this engine. An additional tempering process has been implemented, which eliminates the embrittleness commonly found in PM [powdered metal] valve seats. These seats also have additional seat depth and a reduced leading edge chamfer. Those features provide increased seat to cylinder head contact area for better heat transfer. Inadequate heat transfer may have had a part in the original seat coming out of its counter-bore in the original failure. Once new seat inserts have been installed, they should be machined according to the machining angles the [OEM] has supplied. Doing so will offer optimum engine performance for this engine.’

On the Ford plenums, they’re easy to take apart, clean and put back together. The Chrysler Hemi’s are exactly the opposite. They are 2 pieces that are glued, for lack of a better word, together. Chrysler doesn’t offer them separately, only as a complete unit. There are late model headlight assemblies in use that are glued together, you heat them to separate them. I have passed that idea along to some customers but haven’t had any feedback. We have an ultrasonic cleaner that does an excellent job. To avoid any issues, we clean these suspect manifolds for our customers at no charge.

The worst part about this type of repeat failure is the vehicle owner is usually left holding the bag. The shop or mechanic says it’s not his (or her) fault, ‘All I did was install it!’ If the mechanic or shop has never seen this before, they’d have no way of knowing. On the other hand, most of us don’t read all the printed material we get with products. Most builders I know enclose a “warning” label or instructions pertaining to this. The machine shop or engine builder checks, all the new valve seats they installed are in place so it’s not his (or her) fault. If the engine was purchased through a broker or third party, it’s not their fault either. Who’s left?

In my opinion, Chrysler doesn’t want to admit (neither does Ford) they even have this issue. Presumably that is why I was unable to find any TSB’s (Technical Service Bulletin) listed for the suspect engines from Chrysler or Ford. I also called our local Chrysler and Ford dealers. My contacts there also confirmed there are no bulletins pertaining to this failure.

If this article saves one of you from the horror stories I read and see surrounding this problem, it’s worth the time I spent researching and writing it.

  1. October 22, 2014

    I have a 2008 dodge hemi 3500 truck and I just had cylinder 1 drop a valve seat. I pulled the intake and head off. Next stop machine shop. My truck has only 60k. I payed 45g for my work truck. I’m a vet and I’m pissed

  2. November 24, 2014

    My 2007 Magnum rt was running great, I stopped to get gas and it wouldn’t start. It then finally started, but sounded like the pistons were coming out of the engine.. I had it towed home, I havent looked into it yet, but Im sure it dropped a valve seat!!! Come on this was my toy!!!!

  3. May 7, 2015

    2005 magnum rt sucked valve Nummer 7 pistion cracked in half at 156000 that was a bad day. I put over size seats and guides. valve should never hit piston i broke a valve spring on new stroker motor at 8000, valve stayed and i was so relieved

  4. September 11, 2015

    I have a 2005 Chrysler 300c which the valve seat has broken twice in ten years. Under warranty the first timeand now no warranty. Its a 3700.00 job. Why hasn’t Chrysler recalled these engines? This is a rip-off !!!

  5. September 14, 2015

    i recently rebuilt the 3.7 in my in-law’s 2002 Liberty. a nephew overheated the engine and the head gasket let go. as a result, the passenger side head was “JUST” out. as i recall, it was just .004 beyond the acceptable limit when checked with a straight edge for warpage. i sent the head with cam and caps to a reputable shop to have the head rebuilt with all new valves. i reassembled the rebuilt engine (after same shop bored cylinders and sourced rebuild “kit” with new piston set) and the thing ran like a champ. my in-laws later informed me that the engine was making a ticking noise, from the right side. the right intermediate pipe with the cat on it was problematic, so i initially thought it could be the exhaust… but with only 100 miles on it, i had to invest in a borescope. i found that the rear cylinder had metal in it. from the valve seat coming apart. Ofcourse, the shop wants no part of it, and both myself AND THE SHOP knew before hand that the engine had been overheated… and also that we both knew/know about the valve seat issues on this engine model. So. Now, I once again have someone else’s vehicle parked in my yard waiting to get one or two new heads. I’m just hoping the cylinder wall hasn’t been jacked up by metal flopping around in there.

  6. Four days ago I brought my perfectly running Dodge Magnum (Hemi) into a lube shop to have my fluids checked and air pressure checked before I left town. Three minutes later when I tried to start my car to exit, it would not start. I had my car towed to Dodge and they told me that my #4 cylinder was shot and I needed a new motor. WHAT???!!!! My car didn’t smoke, never overheated, didn’t burn oil, and never had ANY indication anything was wrong. The service writer, service manager and mechanic told me today that the chance of my valve seat coming apart from the head was very, very, very rare (like 1 in a billion) and that they NEVER have to change these motors. I stumbled across this forum and after reading it, have decided to start a petition to have Dodge issue a recall on this issue. Dodge is obviously very aware of this issue and owners like me are stuck with the phenomenal expense of paying for their “glue” job. See the above page- “The Chrysler Hemi’s are exactly the opposite. They are 2 pieces that are glued, for lack of a better word, together. Chrysler doesn’t offer them separately, only as a complete unit.” I am requesting that any Hemi owner that has experienced this same issue contact me so I can add your name to the petition I will be starting. I will also post a link to the petition on this forum as well. Thank you for listening….my Hemi is my baby and I took VERY good care of her!

  7. Alternately you can message me via facebook or at gnawty1@hotmail.com

  8. June 14, 2016

    Yes same problem. 2006 5.7 hemi junk Jeep developed a miss fire. Plugged in my scan tool and and code read #4 MSD solenoid bad. Took a compression test on that cylinder and read 00. Removed head and found dropped valve seat and severe damage to piston and scratched cylinder wall.

  9. June 26, 2016

    2002 jeep liberty dropped # 2 valve seat and ruined engine prematurely.

  10. December 31, 2016

    Hi All
    I’m Curt and i own a 2005 Dodge Ram with a 5.7 Hemi . And at 100 thousand miles mine dropped three valves and took out two pistons as well . Sounds like to me someone needs to do something to resolve this issue with this valve inserts . Because if you have not had this issue yet you will …..

  11. February 22, 2017

    Parked my 05 Grand Cherokee with 3.7. Ran flawless when parked. Fired it back up next morning for work and started clanking like a piece of junk. Mechanic assessed dropped valve seat. Valve blew a hole in my valve cover. 111,000 miles on it. The 1998 jeep we gave my son with the 5.2 has 245,000 miles on it and still going. My wife and I want our old jeep back.

  12. March 3, 2017

    2004 Dodge Ram hemi with 46k miles. Yup, valve spring broke. Babied this thing, kept in the garage it’s whole life, looks like it rolled off the showroom floor. Si 1 spring broke. So now do I replace all of the springs? Nah, I’m selling this time bomb. At the dealer now. Will know if the motor took a big or little hit in the morning. This was my first and last dodge! Dodge builds crap! Never again!!!!!!!!!!!!!

  13. April 8, 2017

    I have a 4.7 Dodge, these engines are over-engineered for our day to day practical needs. The overhead cam trash looks like an attempt at engineering an indy engine for the street. What a total cracker jack prize, complete piece of junk, I feel like running straight to a trade in when I get this engine freshened up, mine left me with a $600.00 tow bill 170 miles from home. the 4.7 is un-necessarily over-engineered with the chain driven overhead cams for more moving parts to fail, but hey it’s their engine not mine. Powdered iron valve seats destine to deliver destruction and the first engine ever capable of destroying a valve cover when a floating rocker arm is kicked thru it’s side. I’m not a engineer but I could engineer a valve seat that would not fall out, ever see the u-joints that were held in place with injected plastic? use the same principle only with injected steel epoxy or aluminum and the seats are in the head to stay. This nation was founded under Common, natural law, never changing moral principals. Those days are gone, all for the o-mighty dollar, now here we are with Designed Obsolescence… When you buy a vehicle you’re purchasing a Carefully engineered Ticking Time Bomb right down to the life of rubber seals, Auto engineers have Destructive labs, they know exactly what their putting on the streets when a vehicle is sold. They have computer monitors all over the engine yet no bi-metal switch to sense abnormally high engine temperatures and kill 4 cylinders when over heating occurs. Sold my old truck with the 5.2, 318 @ 240,000 miles and two years later with 270,000 it’s still going strong. Wish Dodge would have kept the 318, now I’m told the 4.7 has been dropped. It’s without doubt… not for the same reason as the 5.2. I stated previously… Engineers have highly advanced destructive laboratory’s and they know exactly what their selling and about when and what will fail at a given mileage Drop a seat M/F’er!!!

  14. May 5, 2017

    @Anonymous – if you understood a little more of how a cylinder head operates you would know why ‘permanent’ valve seats are not used. If they were, there would be no such thing as a valve job. We would have to replace the cylinder head each time there’s an issue with carbon build up, etc.

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