If your 4.7 WJ dropped a valve seat, please elaborate on the circumstances (year, mileage, speed, oil, etc)
I'm curious what kind of numbers we'll see. It's hardly scientific, but it would be nice to gain some educated insight into frequency as well as other variables.
Both of my 4.7's are still running strong. My '00 is closing in on 180k miles and my wife's '03 is right around 136k miles, IIRC.
My wife has owned her's since '07 and has put the majority of miles on it, so we know most of the maintenance history on it. Never had any issues with overheating, with the exception of when I put the t-stat in backwards and during initial warm up after the install I noticed it going past 210*, which it never does, so subsequently I shut her down and realized my error. :shhh:
My '00 I purchased about 18 months ago for $900 non-running, which was due to a defective ECM. Once I got that resolved, I was pleasantly surprised to hear how quiet and smooth it ran. There was zero service records to be found anywhere in the vehicle, save for an invoice from a dealer doing a trans service about 3 years ago on it. It was lacking in some regular maintenance (belts, hoses, old coolant, etc.), but it hasn't given any indication of severe neglect. I just had the oil pan off this weekend to replace it due to rust, along with replacing the leaking pan gasket and was impressed with how clean the oil pump pick up tube was and there was no bluing on the connecting rods, which usually indicates low or lack or lubrication. I don't see any reason why I should go well past 200k on this motor.
Ive rebuilt 6 4.7 engines myself and none of them had issues with the valve seats. One even warped the heads but the seats were fine. Im kinda at a loss as to why this is thought to be a common issue...
That's why I wanted to try a poll. Even if a forum is representative of a group of enthusiasts and DIYers, it's still a representative sample (of sorts).
Search on here and you will see why......Quite a few on here alone let alone all the other Jeep forums and websites. I had come across it in the motor trade ages before I was an owner or had anything to do with Jeeps. Most don't overheat so you wont find that problem.....any sort of cooling issue that might have led to an overheat is a warning of potential future trouble IMO.
I'd be interested to see the number of '99-'00 4.7's with valve seat failure compared to '01-'04's. There's no doubt that the later hydraulic cooling fan is much more reliable and robust compared to the e-fan that was used the first couple of years.
I'd be interested to see the number of '99-'00 4.7's with valve seat failure compared to '01-'04's. There's no doubt that the later hydraulic cooling fan is much more reliable and robust compared to the e-fan that was used the first couple of years.
I'd rather get rid of the hydraulic fan if I could. It causes a lot of issues. I've read they corrected the valve seat issue in 2001 heads and up which explains the decrease IMO...
The only recurring issue I've noted on here is the solenoid failing, but that still seems to be fairly rare, and there's a work around for those of us with the older 2 wire design via the Ford solenoid and pigtail.
Other than making sure to use the correct fluid and a good quality PS pump, the issues with the hydraulic fan seem far less than the number of bad fan relays and fan motors that plague the factory e-fan setup.
Ive rebuilt 6 4.7 engines myself and none of them had issues with the valve seats. One even warped the heads but the seats were fine. Im kinda at a loss as to why this is thought to be a common issue...
The only recurring issue I've noted on here is the solenoid failing, but that still seems to be fairly rare, and there's a work around for those of us with the older 2 wire design via the Ford solenoid and pigtail. Other than making sure to use the correct fluid and a good quality PS pump, the issues with the hydraulic fan seem far less than the number of bad fan relays and fan motors that plague the factory e-fan setup.
Chris posted the factory spec, but some folks have had issues finding the factory Mopar fluid at their local dealers. There are multiple name brand fluids available at the local parts store that meet the proper fluid specs. Valvoline in the white bottle is available almost everywhere, and if you have an O'Reilly nearby their MasterPro brand fluid sold in a black bottle meets the correct spec.
Mopar®P/N 04883077 Hydraulic fluid / Power steering fluid (MS5931)
MS5931 IS THE ONLY FLUID THAT CAN BE USED FOR THE POWER STEERING SYSTEM. NO EXCEPTIONS!
Important note:
The factory fill power steering fluid for all 1999-2004 Grand Cherokees is a unique fluid, MS5931. ATF+4 (MS9602) should not be mixed or used as a "topping off" fluid on the Grand Cherokee WJ. All WJ models should be serviced using ONLY the special MS5931 fluid. ATF+4 is NOT an approved Power Steering Fluid and should never be used under any circumstances. Note that all fluids will darken in color with usage and fluid color is no longer an indication of fluid condition.
The 4.7 hydro fan is a good setup IMO. Keep fluid fresh by sucking out the PS tank every other oil change is good insurance. I have a magnet hanging down into the fluid to catch ferris ware materials. I tried the magnefine thing but kept having leaks
What happened to this thread? I thought it was a poll on dropped valve seats, not about the kind of power steering fluid to use or whatever.
Do a search on this forum and see the large number of posts on dropped valve seats, my WJ included. Never overheated. Always well cared for. Drove it about 10 miles and stopped at the store before going out into the desert for some serious four wheeling. Engine ran fine to the store. When to restart, barely started, then ran real rough, had to have it towed home. Dropped #8 valve seat. Piston drove valve seat into the valve, broke the rocker arm, pieces of the rocker arm got under the cam and cracked the head, valve dropped part way down into the cylinder, hot gas from the open intake valve partially melted the plastic intake manifold. Engine was toast.
This is a very common 4.7 problem along with broken exhaust manifold bolts and and the non-engine problem with the stupid blend doors. Don't kid yourself, the 4.7 has some serious design problems for this to happen so often. It doesn't wear out, it self destructs. Some engine remanufacturers claim that they have "pinned" the valve seats to prevent this from happening. They wouldn't bother to claim this unless it is a very common problem. I agree that this is not a totally scientific survey but it sure is indicative of a serious engine defect. One mechanic told me that Daimler Benz helped Chrysler design this engine before they sold off Chrysler. Maybe they were PO'ed about buying Chrysler and this was a get even thing. I know I'm still PO'ed at Chrysler about this very expensive problem.
One mechanic told me that Daimler Benz helped Chrysler design this engine before they sold off Chrysler. Maybe they were PO'ed about buying Chrysler and this was a get even thing. I know I'm still PO'ed at Chrysler about this very expensive problem.
Daimler wasn't a part of Chrysler until January of '98. The WJ officially debuted in June of '98. Considering how much R&D goes into a new vehicle and drivetrain, there's no way its even remotely feasible to claim that Daimler helped at all in the original development of the 4.7.
This is one of the biggest pieces of misinformation that continually gets taken as gospel regarding the 4.7 and it really needs to stop.
I'm sorry about your bad luck regarding the engine in your WJ and if it truly had never been overheated, then it may have very well been just bad luck. You also have to consider that high combustion chamber temps can lead to valve seats dropping. This is typically caused by carbon build up from oil blow by and poor quality fuel. Since Chrysler hasn't used an EGR valve to regulate combustion chamber temps since the early 90's, its especially important to regularly change your PCV valve and run a combustion chamber cleaner annually, Mopar offers such a product or you can use seafoam too.
Otherwise the results of this poll so far are pretty telling. The vocal minority will generally make sure everyone knows of their misfortune, whereas the majority of owners out there have no major issues.
Says I may not vote on this poll ??
Anyways, Bought mine with a dropped seat. Its not uncommon. Theres a reason the local pick-n-pull has a steady supply of V8 Wjs with no obvious body damage....I have personally seen at least 20 go through the yard in the last 6 months. They don't have any 4runners !!
The head design is not as robust as other iron block/alum head engines. Leading to eventual head gasket failure with multiple heat cycles. Then it overheats and drops seats.
If you have a good running 4.7 with a few miles on it, I would suggest a pre-emptive head removal and surfacing and new gaskets.
That is strange. Honestly all the ones I see are overheated or don't change the oil and they spin a bearing or throw rods... Really don't see much head issues on the 4.7 here
However I am pals with a couple techs at local store. He has never scene a dropped valve seat on any 4.7 in a Jeep or trucks. He tells they are pretty robust design and they have very few issues. He just retired his 01 DAK with 4.7 and 287K miles.
Pretty much hit the nail on the head. That's kind of the rule for forums in general. People with 'perfect' vehicles have minimal reasons to post on a forum.
Not necessarily. I'm on a forum for each of my cars. I do it to talk to like minded enthusiasts and read about the cars in question to learn new things. The tech stuff is a huge bonus, yes.
Cars are rad. Other people that enjoy the same cars I do are rad.
I'm on the Miata forum for my wife's mx5, but the vibe over there is rather unpleasant at times so i keep my distance. The car is far from perfect at 25 years old and 260k km.
The 3rd car is near mint but the vibe on that forum is so enjoyable it's just a good hang.
I didn't bother to read all these depressing posts but it sure indicates a problem with 4.7 heads.
Of course this doesn't mean that all 4.7 heads are going to fail. Just count yourself lucky if yours hasn't failed, yet.
Somebody should do a search on:
4.7 broken exhaust manifold bolts
The number of WJ's with 4.7's in junk yards with no major body damage should be an interesting statistic. Especially compared to other off-road capable SUV's. At least there will be a large supply of WJ non-engine parts.
Let's see how this unscientific but interesting poll plays out.
I didn't bother to read all these depressing posts but it sure indicates a problem with 4.7 heads.
Of course this doesn't mean that all 4.7 heads are going to fail. Just count yourself lucky if yours hasn't failed, yet.
Somebody should do a search on:
4.7 broken exhaust manifold bolts
The number of WJ's with 4.7's in junk yards with no major body damage should be an interesting statistic. Especially compared to other off-road capable SUV's. At least there will be a large supply of WJ non-engine parts.
Let's see how this unscientific but interesting poll plays out.
.....or the piston skirt thing!....also nothing the owner could stop.
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