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Valve seat drop?

6K views 37 replies 6 participants last post by  optdoug 
#1 ·
Probably.
So I let my son use my jeep today to be to work. He made a stop at the local vape shop, then I get a call from him. He tells me the jeep won't start. I come down to get him and get the jeep started with a jump. I hear a loud rattling sound coming from the engine then it dies. I started it a couple more times and still get the loud rattling. It seems like it just happened for no reason, but I'm pretty sure it's the valve seat. As you can imagine, I'm pretty pissed off right now. I thought I would make it to 300K like I did on my other jeeps. But I guess they just don't make them like they used to.

Any suggestions? The only thing I can think of is a 5K repair or a new car. Neither one of those options sounds very good to me since I still owe about 5K on this one. Is it junk yard time for this jeep?
 
#2 ·
Sorry to here about this. Yes, the scenario is quite typical for the dropped valve seat......warm engine, stop for several minutes, go out and try to start and it either won't or runs like crap with associated noises. Continuing to try to restart only does further damage and will more than likely ruin the piston, the head and maybe score the cylinder wall. You know the options.....used engine, rebuilt engine, fix just the head/piston, etc....depending on what it looks like when torn down. IMO, if you like the vehicle and the rest of it is "sound", you may want to fix it/build it or whatever. Prices can run from around $1000 on up depending on what you want to do. If you could care less about it, you could sell it (broken it won't bring much though) as is, or do a quick fix and then sell it. Either way, you probably won't come out ahead unless you keep your vehicles forever like I do.

I have my 06 Dark Khaki Overland apart right now, havng the valve seats replaced to hopefully keep this from happening. When I get done with the WK, I am going to do the same to my 05 Hemi LX. We travel quite a bit and I don't want to risk this happening when we're away from home. While they're at it, I am having new valve guides, port/polish, new valve springs and a .030 in. mill job.

Keep us posted on what you find, and what you decide to do. If you want to sell it as is, I might be interested, as a pair of 06 Dark Khaki Overland WK's would be kind of cool.....I'd have one lowered and one lifted.
 
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#3 ·
Sorry to here about this. Yes, the scenario is quite typical for the dropped valve seat......warm engine, stop for several minutes, go out and try to start and it either won't or runs like crap with associated noises. Continuing to try to restart only does further damage and will more than likely ruin the piston, the head and maybe score the cylinder wall. You know the options.....used engine, rebuilt engine, fix just the head/piston, etc....depending on what it looks like when torn down. IMO, if you like the vehicle and the rest of it is "sound", you may want to fix it/build it or whatever. Prices can run from around $1000 on up depending on what you want to do. If you could care less about it, you could sell it (broken it won't bring much though) as is, or do a quick fix and then sell it. Either way, you probably won't come out ahead unless you keep your vehicles forever like I do.

I have my 06 Dark Khaki Overland apart right now, havng the valve seats replaced to hopefully keep this from happening. When I get done with the WK, I am going to do the same to my 05 Hemi LX. We travel quite a bit and I don't want to risk this happening when we're away from home. While they're at it, I am having new valve guides, port/polish, new valve springs and a .030 in. mill job.

Keep us posted on what you find, and what you decide to do. If you want to sell it as is, I might be interested, as a pair of 06 Dark Khaki Overland WK's would be kind of cool.....I'd have one lowered and one lifted.
After I got my OME kit installed a month ago, I was really loving this Jeep. It was driving and running better than it ever has over the last year and 11 months that I have owned it. I know you are a guy that really knows his stuff about these Jeeps and from what I have read about this problem, it seems like I'll need at least the head redone. Then possibly the piston and maybe even the cylinder. Then possibly the other head redone as well. I can't see any sense in just fixing the one side and not the other. Knowing my luck, a seat from the other side will drop when I'm in Nevada or one of my other clients far from home. I'm thinking that all that work is probably in the range of about 5K. And the work is way out of my league, so it would have to be done by a shop. I've replaced a couple motors in my day, but that was way back in the 80's. Back then I had the time and the motivation to do it. Now I'm self employed and do not have the time to deal with this. So, if I do keep it. I'll definitely have to pay someone to do it. Do you think my thinking on what needs to be done and the price tag of 5K is within reason. If so, I just might go that route and rent a car until the work is done.
 
#4 ·
I should probably add that I am at 197K miles on this Jeep. So if you think these Jeeps can make it to 300K miles, it might be worth it to repair it. My two XJ's both went 300K pretty easy. I drive a lot, so if I could get another 100K miles out of it, that would last me for at least another two or three years.
 
#5 ·
Any suggestions? The only thing I can think of is a 5K repair or a new car. Neither one of those options sounds very good to me since I still owe about 5K on this one. Is it junk yard time for this jeep?
A used 5.7L engine, with about 100,000 miles runs about $2,400 plus delivery charge. Add to that about 12 hours for installation at $120/hour and you are looking at bill of about $3,840 plus tax. A remanufactured 5.7L from Jeep Parts Depot runs $2,300 plus shipping and installation. I would go with the remanufactured unit if you count on this vehicle.

Separately, at 197,000 miles I imagine the vehicle will need expensive suspension work soon such as ball joints, control arms, inner and outer tie rods, and alignment....

Options:

Sell it now - $1,500 to $2,000
Install new engine - $4,300
Sell with 197,000 miles and reman engine - $5,000
New comparable vehicle with 100,000 - $8,000

If money is tight and you need to drive a lot, I would sell it now and move to a used Toyota or Honda Sedan. While they are not much fun to drive, I have one, they are dramatically less expensive to maintain, repair, and drive than an older Jeep Grand Cherokee, I have one too.
 
#10 ·
Unfortunately it's Sunday so I can't shop around for repair pricing. But if I can find a good used, reman or new engine installed for under 5K, that would probably be the way I would go. Even though this Jeep gave me this problem, I don't know if I want to get rid of it just yet. In my opinion, it's still a god Jeep. It rides great and doesn't drip a drop of oil anywhere.

Money is somewhat of a factor, but I don't think I could settle for a Honda or a Toyota. I was looking at that option last night. Then I came to the realization that that just ain't gonna happen. But I have looked at the older Jeep's as well as the newer ones.

I'm still undecided at this point. But once I can get a few quotes on getting it fixed, I just rent a car for a few days. And I'm not sure how my loan company will handle me either junking the Jeep or selling it. I'm pretty sure once that happens, they will want full payment on the Jeep. I still owe about 5K on it and paying that bill in full would definitely make a dent in the amount of money I would have to buy another one.
 
#6 ·
Man - that really too bad to hear about the valve seats. I've done some reading on this issue, and it seems to be a relatively somewhat common occurrence on these engines with the dissimilar metals used on the valve seats.

If you really dig the vehicle, I'd put a remanufactured engine in it and keep on driving it. It looks like quite a job based on what I'm reading in the manual to remove and replace the engine.

Has the engine ever overheated?? Or do you think it was just bad luck?
 
#12 ·
The engine has never overheated or anything else other than a few sensor and ecm problems. It just kind of happened out of nowhere. But that's what I hear is pretty typical when a seat drops. At this point I'm leaning towards a rebuilt motor replacement.
 
#14 ·
So I got a couple quotes today. It looks like most offer a pretty good raman engine with a 3 year 100K mile warranty. The cost seems to be around $6000.00. So now I'm debating if I should keep it or get the rebuilt engine. But this is a pretty damn good Jeep and I really don't wan't to dump it.
 
#16 ·
As far as I know, the dropped valve seat issue in the early 5.7's is limited to the 05-06 years. That's why I am being proactive and doing both of mine ASAP. I hear where you're coming from on "stepping down" to a smaller vehicle, even though the fuel economy is better. My attitude on that is that when everyone drives small vehicles, then I will. I couldn't see driving around in a small vehicle and getting hit (potentially) by a Ford Expedition or Chevy Suburban. For sure I'd come out on the short end of that. The early WK's like ours have 5 Star ratings for both front and side collisions and, IMO, would hold up a lot better in such a collision. I also, don't care that much about fuel economy, as long as it's half way reasonable.....about 10 or more in town and above about 15 on the highway. To me, trying to improve the fuel economy on these "slugs" is sort of a game, plus I love to tinker. So far, on my 06 5.7, I've improved the highway fuel economy by about 25%....(16-18 mpg to 21-23 mpg), not bad for a ~400 hp., ~5300 lb. (wet) "barn door" cruising down the highway.

On yours, Doug, RCS1300, in his Post No. 5, has some valid points regarding prices and possible repairs that may be in the future. IMO, one big downside to dumping it now is that you're pretty much upside down in that you still owe $$$ on it, and would take a pretty fair hit if you dump it. As I said earlier, if you like the vehicle and it is otherwise fairly sound, go ahead and spring for the repair. Normal fair wear and tear items will happen with any vehicle and to get something different now, you MAY incur initial costs getting it up to speed in the maintenance department. With either a repaired or new engine, at least you'll know exactly what you have.

FWIW, I think I'd first tear it down and see just how bad it is. You may be surprised!! If it didn't damage the cylinder wall or piston, the cost of repair would probably be less than $1000, plus labor. If the head hasn't been destroyed, that would be even better if it could be repaired. In any case, for sure do both heads for the reason you stated above....don't want it happening again. In your area, I would think there should be a good machine shop that specializes in either/both engine/head rebuilds. I'd also guarantee that, if they do heads, they're familiar with the early Hemi valve seat issue. Valve seats alone are not too expensive.....~$8-12 each and maybe up to ~$200 to R and R them.....maybe in California a bit more. So, say you're looking at $500-800 to have heads redone (if both are rebuildable) plus the labor to R and R the heads. Also, if the prices climbs by quite a bit (depending on what's wrong and what it costs to repair it), you'd want to factor in the existing mileage on the engine and perhaps go with the rebuilt/remanufactured engine. Something to think about for sure.

If you're going to take it to a local shop, find an independent that has a good reputation (ask around.....friends, family, neighbors, social media, etc.) and have them tear it down. Be sure to be there when it's completely torn down so you can see exactly what it looks like and what needs to be repaired. DO NOT let them sell you a bill of goods by saying other stuff needs to be done, unless it truly needs it. I think you said you had some previous wrenching/engine maintenance background, so this will be in your favor. Things you SHOULD have done though (repaired/replaced) would be anything that would require future "invasive" maintenance/tear down to repair in the future. For instance, on mine, I am replacing both heater hoses, the heater hose hard line o-rings that go under the intake manifold, and the MAP Sensor. On yours, if you still have the stock exhaust logs, replace all the exhaust log bolts/nuts/studs with better quality components, and inspect the logs for damage/cracks. Install better quality exhaust manifold gaskets (Percy's Seal for Life P/N 66075 if you're using stock logs....about $30), and consider using Nord-Lock Wedge washers (http://www.nord-lock.com/bolted/watch-the-new-junker-test-video-here/) to insure they won't come loose. A "top end" gasket kit will run about $200 from RockAuto. New spark plugs and an oil change would also be in order. Also, while the heads are off, check/repair the potential problem "yellow wire" on the starter. Others may also think of other things that should be done while the heads are off.

Good luck and keep us posted on your direction and findings.
 
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#17 ·
After reading the massive amount of threads to this, it seems heat soak is the ultimate cause. Which occurs when you shut off the engine after "spirited" driving, or a long haul. And then start it back up again within several minutes.

I know many have tweaked their fan settings, and installed 180 thermostats. But am I naive to think that running the fan for a few minutes after powering off the engine would help mitigate the heat soak issue? I realize coolant wouldn't be circulating at this point, but it may displace some of that combustion heat that seems to soak into the engine after powering it off.
 
#18 ·
Wouldn'tcall it naive
However that fan sucks cooler air through the radiator
By the time that air has come through the radiator it's also prity hot, IMO doing good little to cool off the engine
If one would like to drop the engine temp, would rather suggest letting it idle for a few minutes that the whole system cools down

Or

Removing the plastic engine cover, have seen a video, where removing the engine cover drops the temp around the inlet manifold by a significant amount to influence performance , that was a performance linked video advice

Or

Fitting some vents on the bonnet to help get the hot air out, and removing the plastic engine cover
 
#19 ·
I dropped off the Jeep on Tuesday for a full rebuild. It should be done next week. Im going to the machine shop tomorrow to see what it looks like inside. I'll probably save the piston if it looks bad. I figure it will make a nice paperweight.
 
#20 ·
Define what they call a "full rebuild". Are they pulling the engine? Are they rebuilding that one or giving you a complete different one? Are the going to insure it has new valve seats in whatever heads they use?

The reason I ask is because one week sounds pretty ambitious, especially if they're using your existing engine and rebuilding it. If they're installing an "already rebuilt" engine that's not too bad.

Keep us posted.
 
#21 ·
Define what they call a "full rebuild". Are they pulling the engine? Are they rebuilding that one or giving you a complete different one? Are the going to insure it has new valve seats in whatever heads they use?

The reason I ask is because one week sounds pretty ambitious, especially if they're using your existing engine and rebuilding it. If they're installing an "already rebuilt" engine that's not too bad.

Keep us posted.
They said it will be a full rebuild. The only parts that will be reused are the heads (But they will have new valve seats and valves. The block, the crank and the connecting rods. Everything else will be new. I opted for this because the place shop I took it too has been around for a long time and is considered to be a great repair shop. The machine shop that is doing some of the work is also a highly rated place. It's a little more expensive than I thought it would be, but if I get what I am paying for, it should be worth it. The motor has been eating too much oil lately as well. So hopefully new pistons and rings will fix that issue. I could have saved a ton of money just fixing the one cylinder and head. But knowing my luck, the other side would give out soon anyway.

The total repair time is going to be more like two weeks. I just talked to him today and was told if all goes well, I should have it back by next Friday. The engine is already out of the Jeep and disassembled. I am probably going to go down and take a look. I meant to go down this week as well, but work kept me too busy to go.

hopefully I can get a few pictures of the damage. If I do, I'll post them here.
 
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#25 ·
I am glad to hear you have trustworthy independent repair and machine shops in your area. A lot of places don't have such a "luxury". The fact that they've been around for years should be a testament to the quality of their work. If they did shoddy work, they for sure wouldn't be around that long......word gets out.

It's fairly well known that Chrysler products are sensitive to the type of O2 Sensor used, especially the upstream ones. I still retained the downstream Bosch ones, as their proper operation is not dependent on the time it takes them to warm up and begin sampling like the upstream ones are. The upstream O2 readings are one of the primary inputs, in conjunction with other engine management sensors, that will, at a minimum, impact both performance and fuel economy. If yours haven't been changed in almost 200K, they are for sure overdue and, IMO, this is a wise decision to change them. I think your P2172 DTC was probably related some how to the dropped valve seat and, when cleared and the new engine installed probably will not return. Also, replacing the MAP Sensor and PCV Valve is a good idea. While it may not really need it, it won't hurt to replace the Throttle Body too. If you want to save a few bucks, you could have them leave the original on it, and if you have problems after the engine is installed, then replace it. This is only about a 15 minute job, as it is easily accessible, and the calibration to the PCM is easily done. This is also something you can do yourself (both purchase and install) whenever you choose.

The MDS has a multitude of inputs to the PCM that must be met in order for the MDS to activate. A few of the key ones are engine load and coolant temperature, and oil pressure. You may want to consider adding an MDS "ON" light, so you can know, with certainty, when it is active and when it is not. If you have an aftermarket exhaust you already may be able to tell when it is active. Back in 2004, over on one of the LX forums, I came up with this idea and did a "how to" thread. The installation is the exactly the same on our WK's, including wire colors.....actually even easier. FWIW, here's the reference under my screen name, magnuman over on that forum:
http://www.lxforums.com/board/engin...stallation-mds-indicator-light.html#post55813

Regarding the transmission service, I wouldn't recommend a "flush", but just a fluid and filters change. While you're at it, if you plan to keep the WK for a long while, you may want to consider a Dorman transmission pan with a drain plug. It'll make this job a lot easier next time. The Dorman part number is: P/N 265-817. Here's the Dorman web site showing the number:
https://www.dormanproducts.com/gsea...erokee&origin=YMM&parttype=Transmission%20Pan
If you do this, just plug the P/N into your search engine and find out who has the best price.....should be under $30.

Good luck and continue to keep us posted on your progress.
 
#26 ·
Unfortunately, today was the first day I could get down to the shop. Most of my parts had already been put in the garbage. But the guy who as putting my motor back together was good enough to fish the bad piston out of the trash for me.

These little valve seats don't play. When they drop, they destroy.
 

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#27 ·
Here are a few pics of the motor being reassembled. It looks better in person. The owner said it should be done and sent back to the auto shop by the end of the day. If I'm lucky, I'll have it back on Friday! Im really getting tired of driving this Jeep Renegade I'm renting.
 

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#30 ·
Looks really nice. Do you know what kind of pistons they put in......forged, sand cast, etc.? Are you going with the stock cam?
 
#31 ·
That's a good question. Im not sure what kind of pistons they are. I didn't ask. And the cam is a stock cam. But the owner seemed pretty confident that it would last for 200 to 300K miles.

Oh, and the owner is the same guy who was there back in the late 70's when I went there a few times in high school. He's a lot older now and has a couple younger guys who actually do the work. Now he just stands around and tells everyone what to do. Lol. But I'm pretty confident I'm getting a great rebuild.

I'm not sure if it will go 200K or more. But I don't plan on having it for more than another three years or so. At that time I'll probably have around 100 to 150K miles on it. And as long as it doesn't eat two quarts of oil between oil changes and MDS works again, I'll be pretty darn happy.

And lastly, even though the cost of this repair really pissed me off. It is pretty exciting watching it happen. The last time I tore an engine down this far, was in the 80's when I was in my twenties. All I had back then was a couple friends helping and a Chiltons manual. We had no internet back then. But it was still fun. The only difference this time is that I'm not actually doing the work. Im just watching.
 
#32 ·
Im filled with anticipation today. It's been a long two weeks since I have driven my Jeep and I can't wait to get it back.

I stopped at the shop today to take a look and the owner confirmed it would be done today barring any unforeseen problems. But the motor is in and they were about to put the new MDS sensors and new intake in. Unfortunately they couldn't guarantee that they could get all the metal put of the intake so I had to buy a new oem replacement. But at least it should be running better than ever and MSS will work again. No more 12 mpg!!!

I'll post some pics of the finished product later. But I feel like a child who can't go to sleep on Christmas eve. Haha.
 
#33 ·
Im filled with anticipation today. It's been a long two weeks since I have driven my Jeep and I can't wait to get it back.

I stopped at the shop today to take a look and the owner confirmed it would be done today barring any unforeseen problems. But the motor is in and they were about to put the new MDS sensors and new intake in. Unfortunately they couldn't guarantee that they could get all the metal put of the intake so I had to buy a new oem replacement. But at least it should be running better than ever and MSS will work again. No more 12 mpg!!!

I'll post some pics of the finished product later. But I feel like a child who can't go to sleep on Christmas eve. Haha.
I get around 18 on the highway with my mds turned off and a good tune.
 
#34 ·
So I got the Jeep back on Friday night. And it sure feels nice to be back in the old Jeep. I was renting a Jeep Renegade for the last two weeks. And while it was kind on nice driving a new car, it just wasn't working for me. Those Jeeps are just way to small.

But the good news is that the Jeep is back on the road and running better than ever. The engine and heads have been rebuilt from the ground up and there seems to be a lot more power than it had before the rebuild. Maybe I'm just imagining the extra power, but I don't think so. I live about 5 miles up the hill from the flat lands and although I have not given it full throttle yet, it goes up the hill at 40 mph barely depressing the gas pedal.

All in all everything is great. The only downside is that I did spend a little over 7K to get it totally rebuilt. I ended up spending a little over 1K more than I was quoted. Mostly because I ended up having them replace all of the hoses, water pump, intake manifold (The machine shop and the auto shop both recommended it because they said they would not guarantee that all of the shrapnel could be removed from the intake. I took a look at the manifold and to me it looked like they were right.), MDS solenoids, AC charge ( And the AC is ice cold now.) and a few other little things that I can't remember. The only thing I didn't have them replace was the O2 sensors. The total bill just about emptied my checking account, so I figured I would replace them myself at a later date. I'm an independent contractor so I don't get a steady paycheck. But I should have more money coming this week. So, I'll probably get them sometime after I get paid by someone.

All in all it's great and I'm happy that I spent the money on a rebuild instead of buying something else. I keep the Jeep in pretty pristine condition, so I don't think I can find another equivalent Jeep for 7K or less.
 
#37 ·
Glad to see you got it back and it's running great. You're right, spending that kind of $$$ hurts but, as you said, you wouldn't be able to replace it for that.....plus you know exactly what you have, unlike if you ended up buying some othe used vehicle that was unknown to you.
 
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