4.7 Dropped Valve Seat - YEAR POLL - Page 3 - JeepForum.com
View Poll Results: What year was your dropped valve 4.7?
1999 8 11.59%
2000 10 14.49%
2001 8 11.59%
2002 19 27.54%
2003 3 4.35%
2004 22 31.88%
Multiple Choice Poll. Voters: 69. You may not vote on this poll

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post #31 of 171 Old 10-07-2016, 03:37 PM
skain8
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Quote:
Originally Posted by LaddieHanus
My Wife's 2004 Didn't drop a valve seat but blew a head gasket. I told my machine shop to go ahead and replace the seats anyway and his opinion was that if the head gasket hadn't blown I would have dropped a seat sometime later. Did a full rebuild including valve seats new rings polished crank It had blown a radiator about a year before and had overheated. The engine was rebuilt at 207537 miles and I finished installing it today, runs great. My wife likes her wj and doesn't like the looks of the WK and WK2. Next 4.7 I work on will only have 6 cylinders (stroked 4.0) in my 89 wrangler/
If you don't mind sharing, what was the repair cost for the valve work?


'02 WJ: 4.7L, 5", HP44/9", 231HD, tall & skinny KM2's

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post #32 of 171 Old 10-30-2016, 12:15 AM
TheBoogieman
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2000 4.7 with no problems at 135,000 miles.

Quote:
Originally Posted by jeepinmichguy_ View Post
TheBoogieman is a jerk.
2003' Rubicon/Zone 4.25" combo lift with Rancho RS5000X shocks/ Zone hydro shocks/5.13 gears/35" Mickey Thompson MTZ P3 tires/Black Magic brakes. Jeep #17 & 19.
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post #33 of 171 Old 11-06-2016, 04:12 AM
torchd
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I have a 2003 HO with 168K on the clock with zero problems. I just bought my Jeep in July of 2016. The first thing I did was do a complete coolant flush and new t-stat.


Answer me this, how are you guys dropping valve seats? Is it from overheating one time, then BAM that's it?

1998 Jeep Grand Cherokee Laredo
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post #34 of 171 Old 11-07-2016, 09:43 PM
losttech
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I bought a high mileage 99WJ 4.7 for 1k that had a bad ECM it turned out would run but always shut down it has almost 200k on the clock.
It sounds and runs perfect really the smoothest V-8 I think I have every drove.
I am not going to worry about valve seats on it just do oil changes like I should I did upgrade the clutch fan to an 11 blade GM fan as the 99-00 have the old style e-fan and clutch fan and I don't trust the E-fans at all after my 4.0 almost got fried by a dead fan.
So who knows if I could get 50k would be super happy it was dirt cheap and is almost perfect besides a few weepy seals.
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post #35 of 171 Old 12-05-2016, 01:04 PM
oldfamilyguy
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Quote:
I did upgrade the clutch fan to an 11 blade GM fan as the 99-00 have the old style e-fan and clutch fan and I don't trust the E-fans
Is the fan upgrade the blades only or a complete clutch and fan assembly? Is it a direct spin onto the water pump and something common to find. ie. lots in the junk yard and cheap.

My wj is a 2000 with 170,000 on it, no valve seat drop (yet). Its never been hot and always has clean oil.
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post #36 of 171 Old 12-06-2016, 06:52 PM
losttech
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Quote:
Originally Posted by oldfamilyguy View Post
Is the fan upgrade the blades only or a complete clutch and fan assembly? Is it a direct spin onto the water pump and something common to find. ie. lots in the junk yard and cheap.

My wj is a 2000 with 170,000 on it, no valve seat drop (yet). Its never been hot and always has clean oil.
Its clutch and fan for the 4.7 it has to be modded a the fan because its a little to big.
There is another combo that should fit better but haven't tried it myself a dorman 620-149 and a 2794 clutch its a 18 inch fan ford versus a 19 inch gm fan.
There is a huge thread on this as it is mostly for the 4.0's the 4.7 switched to the steering pump fan in 01 so only 99-00 have the e-fan and clutch combo.
Here is the thread the last page we are talking about the V-8 applications since I think only one other guy tried it on a V-8 besides me.
jeepsterpitt is the guy been blazing the trail on this stuff but doesn't have a V-8 to mess with so I give him feedback and other guys when we try it on ours.
The good thing about he V-8 is it always has the clutch fan not just the e-fan so if you do loose the e-fan it will stay cool as long as your moving but will overheat when stopped.
I just did mine as a test and to not have to worry about it.
https://www.jeepforum.com/forum/f310/...grade-3233369/
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post #37 of 171 Old 12-06-2016, 10:34 PM
oldfamilyguy
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thanks for that link, mega thread there. Actually why I was asking is for my wifes wk with a 3.7. Its only got the e fan nothing else. So ya I want to add a clutch fan to it. I think its the same water pump as the 4.7 so just started to check out what's compatible and head to the junk yard. No wk's there last time I looked but lots of other chrysler models.

Oh I guess I should say, kind of relevant to the topic here, 3.7's don't seem to like the heat any more than the 4.7
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post #38 of 171 Old 12-16-2016, 02:29 AM
Zackai
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2002 4.7L HO. Had a Valve seat drop 2 years ago, cost me about $3,500 to fix it. Should have immediately sold it, as it just dropped another one last week, and I can't logic spending another $3,500 on a vehicle with this low a value....

RIP my Jeep, and this great but awful engine.

2002 Jeep Grand Cherokee
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post #39 of 171 Old 12-17-2016, 09:49 AM
sdg3205
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Quote:
Originally Posted by Zackai
2002 4.7L HO. Had a Valve seat drop 2 years ago, cost me about $3,500 to fix it. Should have immediately sold it, as it just dropped another one last week, and I can't logic spending another $3,500 on a vehicle with this low a value.... RIP my Jeep, and this great but awful engine.
Ahh balls. When you had it repaired 2 years ago did they not replace both heads with improved seat techniques? Same head or other side?
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post #40 of 171 Old 12-18-2016, 08:54 AM
JohnnyV
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Looks like the 2002 4.7 has the most dropped valves! I'm interested as I have the same.

Was wondering with the dropped valved group if they were using conventional or synthetic oil?

2002 WJ Limited 4.7L - Inferno Red
1995 ZJ Laredo 4.0L
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post #41 of 171 Old 12-18-2016, 11:43 AM
alfaitalia
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Don't think it would make much difference...no oil near the valve seats.....hopefully. If you are suggesting the motor runs cooler with fully synth...well I bet you would struggle to measure the difference...If there indeed was a difference to measure.

If you can't fix it with a hammer, you've got yourself an electrical problem!
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post #42 of 171 Old 12-18-2016, 12:00 PM
JohnnyV
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Nawh... not suggesting the engine will run cooler. Is overheating the only reason for dropped valves? Could it be a stuck rocker arm or rod from oil sludge buildup also contributing to a dropped valve?

2002 WJ Limited 4.7L - Inferno Red
1995 ZJ Laredo 4.0L
1989 XJ Laredo 4.0L - Sold
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post #43 of 171 Old 12-18-2016, 12:52 PM
sdg3205
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Quote:
Originally Posted by JohnnyV
Nawh... not suggesting the engine will run cooler. Is overheating the only reason for dropped valves? Could it be a stuck rocker arm or rod from oil slug buildup also contributing to a dropped valve?
Heat sink/differential between the two metals is thought to cause expansion/contraction discrepancies that leads to the seat falling but there is still no concrete answer.
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post #44 of 171 Old 12-18-2016, 02:04 PM
oldfamilyguy
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An engine shop I know says there just not a tight enough fit. Any he's built, 3.7 and 5.7 too, they replace them with a tighter fit. In his opinion its still a result of an overheat, though many swear they've never been hot, but still they shouldn't get loose that easy.
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post #45 of 171 Old 12-18-2016, 07:44 PM
HarryH3
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I've read that excessive ping/detonation can contribute to the problem as well. It makes the combustion chamber temps go way above normal. The aluminum head expands more than the steel valve seat as it heats up.
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