4.7 HO go BOOM!!!!

[HammerZ71]

Well I started a thread in the Ram section about my 4.7 dropping a valve seat and taking out cylinder #2. I am going to continue it here, where it should be - but this should be of interest to ALL 4.7 owners.

Finally got the heads off (and I'll be honest - this will be my LAST OHC modular engine!) I've gotten heads off of 4.0 I6s in an hour and a half. Took my over 7 hours to get the heads off this SOB!

As expected the aluminum head is toast. As suspected the piston in cylinder #2 is toast. What I found that I did not expect was that BOTH heads were done! Seems the valve seat exploded and debris went up into the intake manifold and made it to the other head.



and I don't think this piston is re-usable, LOL...



So I got a local quote from a reputable shop on re-manning the heads and re-pressing all valve seats at $380 if I supply the seals. Found an all-inclusive master overhaul kit for $700 to the door - WITH 8 new, balanced pistons (might as well make this a TOTAL rebuild). So about the only other parts costs I'm gonna have are water pump and oil pump (again, the originals are ok, but with 102k on 'em I only wanna do this once) and then just plugs, fluids and filters...

I hope to have the kit tuesday so I can take the valve seals out and get them and the heads to the shop so I can get started...

[Cashman]

Ouch! That sucks man good luck with the rebuild!

[LB3711]

that sucks. my 4.7 was going strong with no issues at 106k

Sent from my Transformer TF101 using Tapatalk 2

[SmokedRam]

Dammit man!!!

[HammerZ71]

I've finally gotten over the being pissed phase that I was in due to an over well maintained, never abused, never overheated 4.7 would drop a valve at 102k miles and I'm actually looking forward to the rebuild as a project.

I have always said "make any repair a mod" and I wish I could on this one. I'd love to upgrade some components like a polished intake, heads and maybe even go with higher end cams than the HO's that are in it. Would be the perfect time to bore them cylinders out too since I'm gonna have to hone 'em a bit for new piston install. But alas, funds are VERY low and I'm basically going into hoc just for the standard rebuild and I need my daily driver on the road ASAP...

[AWE Daniel]

Damn sucks to see that, seems like the 4.7s just go crazy sometimes. I betchu will have it all fixed up and purty in no time!

[HammerZ71]

Hopefully the rebuild goes smooth. This here engine is a lot more complicated than the only other one I've ever done (4.0 I6).

Need to get it up and running, even though it's lifted 3", it still gets about 6 MPG better than my truck which is now my daily driver:

[repoman]

looks almost like what happended to my truck my truck few weeks ago!

[HammerZ71]

Originally Posted by repoman looks almost like what happended to my truck my truck few weeks ago!

4.7 or Hemi?

I'm finding out that the valve seat issue in the 3.7 V6 and 4.7 V8 are a LOT more common than I ever thought.

A lot of times with even mild over-heats the valve seats go - the aluminum heads expand while the pressed-on, hardened steel seats don't and they just drop out - but they go unreported by vehicle owners because it's simply called "warped heads" by the mechanic. So A LOT of these head gasket and/or warped head issues we read about with the 4.7 all the time are in actuality the valve seat failure.

Although mine's never gotten over about 215* the whole time I've had it, so even though it's more common with over-heats, it can happen to any of 'em...

[repoman]

hemi....crank bearings let loose and nuked the wole thing heads and block...those 4.7's are a pain i heard alot of the dropping out like that....i got about 1400 in motor, parts as of now...since that 4.7 is based on a mercedes motor i wonder why right? chrysler droped the ball years ago....hemi issue is the same more in 03-04 years the famous "hemi tick" same things mopar ate the bill on that one 05+ they used better builds and parts to beef up the top ends on the hemi as far a 4.7s might take time but i think they did same thing in newer years