Jeep Enthusiast Forums banner

What year was your dropped valve 4.7?

  • 1999

    Votes: 9 11.5%
  • 2000

    Votes: 12 15.4%
  • 2001

    Votes: 10 12.8%
  • 2002

    Votes: 21 26.9%
  • 2003

    Votes: 3 3.8%
  • 2004

    Votes: 24 30.8%
141 - 160 of 216 Posts

·
Registered
Joined
·
36 Posts
Anyway, I wanted just to put eyes on these (I'm a very visual person) and did a search for "4.7l head removal" There is a boobtube video a guy made with about 4 different episodes. something interesting I noticed is that the 'owner' decided to go with rebuilt heads. In the last video, it shows him unpacking them, and you can clearly see divits all the way around each of the valve seats. The man says in the video that the place he ordered them from told him they were 'bulletproof'. In another video I found searching for "dropped valve seat" a guy takes apart a I guess maybe a 15 HP air cooled 4 stroke from a yard machine. It in fact has a dropped valve seats which he procedes to reinstall after cleaning up the head with a dremel, and subsequently uses a center punch to run divits all the way around the valve seats on the aluminum head. I suppose in effect pushing the metal tighter in. It looks horribly unprofessional... I suppose its not important.
I think the industry term for this is called staking. It's usually used on nuts on axles or transmissions to prevent loosening through rotation, but it works to keep things captive as well. So maybe they didn't increase the press fit and just made it captive instead. So who cares if the actual press fit stops working, those staking distortions will prevent it from falling or rotating.
 

·
Registered
Joined
·
220 Posts
It was an arm, a leg, and then another arm. $3400 by the time it was all said and done, but I got two completely new refurb heads. But I didn't pay it. Had it been a necessary vehicle for us I would have fixed it myself, but this car was going to a family member who only had $4500 to purchase a car. So it was either this vehicle, that she at least knows the history of and at the end of the day is a mostly refreshed engine including water pump and timing chain maintenance items, or someone else's garbage. I pretty much just gave her the car, because I would have only gotten a few hundred bucks for a jeep that has a severe misfire and couldn't morally sell it to someone knowing there was probably something major wrong with the engine.

I can't confirm it was a valve seat, but that's what the mechanic said it was, and new heads did completely fix the misfire.
Holy crap! I had my head gaskets done and heads refurbed for about $2000 including the parts, labor, and machining. Mine had a cylinder 1 misfire from a very minor headgasket leak, but the machine shop said the valve seat on that cylinder was a little rough, just like with yours.
 

·
Registered
Joined
·
41 Posts
I think the industry term for this is called staking. It's usually used on nuts on axles or transmissions to prevent loosening through rotation, but it works to keep things captive as well. So maybe they didn't increase the press fit and just made it captive instead. So who cares if the actual press fit stops working, those staking distortions will prevent it from falling or rotating.
Thank you for the proper term. Knowledge long lost.

I got the valves staked, but I had a little more to say, and I didnt want to hijack this thread, so I started a new one:

https://www.jeepforum.com/forum/f310/staking-4-7l-valve-seats-4398931/#post40975823

Hope it works *finger crossed* :grin2:
 

·
Registered
Joined
·
31 Posts
Have a 2004 overland with the HO just went though the engine at 230000 miles, seat shattered and destroyed piston now all fresh and back on the road. Did Mopar ever fix this problem on the heads? Reason I ask is I also have an 07 non ho with 132000 showing and still runs like a top.
 

·
Registered
Joined
·
718 Posts
230K is a good run for any engine. I have 2. A 2000 with 167k and a 04 HO with 138K, both acquired used. I am concerned about this issue but only time will tell. My understanding is JEEP never changed the design all the years they made this engine. They consider it a non issue and the design is solid. Go figure.
 

·
Mopar Nut
Joined
·
586 Posts
Just added a '99 N and an '04 J to the poll. The '99 dropped at 173k. She was stripped and scrapped. The '04 dropped at 112k, shortly after I bought it. She too was stripped and scrapped, but I kept the HO motor and she rests on a stand waiting for a rebuild. Heads still remain in place. When the day comes, I'll post pics of the damage here.
 

·
Premium Member
Joined
·
2,179 Posts
Dropped an intake seat number 1 cyl Thursday morning. Dropped as I started it in the driveway, I had driven earlier to the store, never even reached operating temp nor has it ever run hot since I replaced both heads less than 16 months and 12,000 miles ago. So yes, the remanned head dropped a seat. Clearwater Cylinder Heads sells absolute junk IMO and according to the hundreds of scathing reviews I am not alone in that opinion. They offered another head AFTER I ship their crap one across the country, wait 3 weeks for "Bob" to look at it and he deems it their fault. Thing is there are hundreds of reviews saying he NEVER claims responsibility and has a warranty denial rate that is off the charts. Not to mention one could not pay me to install another one of their junk heads just to have it fail like the first one did. I ordered another single head from Cylinder Heads International in Texas, these guys are very familiar with the other clown I dealt with and the man I talked to shared quite a few stories of the other clowns antics. He sold me a remanned head, they replace the seats with real steel vs the powdered metal crap, the real steel ones are able to be pressed in at a much tighter tolerance than the powdered ones. He also gave it to me at a discounted price seeing I had to deal with Bob the clown. I cannot afford to do both AGAIN at this time, in spring I will purchase another from CHI for the passenger side.
 
  • Like
Reactions: Stay Stoney

·
Premium Member
Joined
·
2,179 Posts
12,000 miles....
 

Attachments

·
Registered
Joined
·
41 Posts
I Think Clearwater Cylinder Heads may have been one of the places I eyeballed earlier this year before I refreshed mine instead of replacing. Always good to let people know about companies that dont do good work/stand behind their product.


Is that pic from the head with 12,000 miles on it? seems like an aweful lot of carbon for 12k...
 

·
Premium Member
Joined
·
2,179 Posts
Yes, around 12,000 miles on it. I thought the same until I realized the combustion chamber had been painted! Cylinder on the other end had paint peeling off it pretty bad, I am sure the cylinder liked that. Looked like this when I got them.
 

Attachments

·
Registered
WJ 4.7 HO my 2002
Joined
·
684 Posts
@cDee63,
I remember that when you bought the heads, they said that the valve seats have been stacked in order to prevent dropping.
Am I wrong remembering, or am I not seeing the stacking?
 

·
Registered
Joined
·
41 Posts
Yeah def not staked.



I'm looking at the black carbon on the valve. whats on the mating surface appears to be part of the gasket? But if that is 12k, you have a serious oil burning problem.


On my 4.7 H.O. it has a venturi style drainback PCV. I have been meaning to replace them with with a screen filter style which, I hope, will prevent some of the oil burning these engines do.


I mention this because oil burning could affect cylinder temps.
 

·
Premium Member
Joined
·
2,179 Posts
It uses no oil at all, when I change it at 4000 the level is exactly where it was when changed last time. No smoke, nothing. I have a catch can and a modified PCV system derived from the later ones, usually about a tablespoon of oil every thousand miles. That cylinder is the only one with crud on the valves, notice number 2 in the background has cleaner valves. Not only were they not staked I was also told the seats were replaced with real steel ones, that didn't happen either. My local machinist gave me a steel seat, Stellite, and attempting to mar the surface is impossible with my crappy wire cutters yet they will put a noticeable dent in the seat part that broke off. He looked at it for a second and knew it came from a Chrysler, does a lot of them on early Hemis that have the same issue. I believe I was jipped on the valve stem seals as well, probably used as cheap as possible. And now that the new head is on the hits just keep coming, this is what happened on initial start last night..
 

Attachments

141 - 160 of 216 Posts
Top