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2005 4.7L blown head hasket

12K views 67 replies 13 participants last post by  jamsomito 
#1 ·
Looking for some insight from some folks who have experience with this engine. I've been doing a ton of research the last several weeks and there's just a lot of financial risk involved with my choices. Unfortunately both our cars blew up the last 3 months and the dishwasher just went as well, and the wife and I are expecting a baby in the next month so both time and money are a little tight currently. I'd take this on myself normally, but with the baby on the way it's just not an option at the current point in time :(.

So I have a bad head gasket. It was showing the typical symptoms (fluid rushing through heater core, overheating at idle, slowly burning coolant, big puff of coolant smoke when starting), and eventually it gave me a cylinder 8 misfire code with the check engine light. Took it in, pressure tested, confirmed bad head gasket. So here we are. Jeep is 2005 Grand Cherokee with 148,000mi on it. I just put on new shocks/struts all around, new brakes, finally got the transfer case working after the horrendous recalls on it, wheel bearings, and the transmission valves and solenoids packs have been replaced. In other words, there's value in fixing the vehicle.

My options seem to be:
1) tear it down, replace all gaskets. Machine heads if necessary (though I understand they only have about 2 thousanths of allowance for machining - either not much or none at all)
2) tear it down, replace all gaskets and both heads.
3) only tear down enough to replace engine with remanufactured engine.

The jeep did get hot 2-3 times. Never hot enough to boil the coolant and blow the radiator, and never hot enough to pin the temp gauge. However, the temp gauge has gotten into the red a few times. I hear it doesn't take much to warp these aluminum heads, but I don't know if this is enough to do it. So, the state of the current heads is a question mark. Then there's also the question of the valve seats / valves and rockers which both seem to be an issue on this engine as well.

Both the oil and coolant are normal, so I believe piston rings to be in good shape, and I don't believe any coolant would have gotten into the block to kill the bearings. But again, a question mark.

There are absolutely no used engines in the area that are worth buying - all with 130,000mi or more. If I replace the engine, it would have to be a reman unit. I like the idea of 100,000mi warranty on the engine again too.

I'm aiming for the cheapest repair possible due to my current situation. But I want it to be reliable too. If they tear down the engine to replace heads I am also amenable to opportune replacements like oil pump, water pump, etc, etc.

So, to anyone who's deeply familiar with this engine, is it worth risking tearing down to target the repair, or in the end is it just wasting labor dollars when an engine replacement is the end result anyway? Thoughts? Many thanks in advance.
 
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#2 ·
That’s some awful luck lately, damn! Well, I can tell you that tearing it down and doing the headgaskets/machining the heads (or replacing them if needed) but doing all the work yourself you’re saving $1500/1800 over the price of a remaned engine. (assuming you do replace items like oil pump, water pump, etc at the same time) If you’re having a shop do all the work though I’m wondering if the labor they’d charge you it might be even closer cost wise to just swap the engine for a reman. Headgaskets on this are quite labor intensive and remans go for like $2700.

We just had a baby (3 months old now) as well so I can commiserate with your feelings. If this was my daily driver I think I’d go with a reman. The 4.7 I’m rebuilding I picked up as a project so I can afford to test the reliability for a while, but a daily driver with a baby on the way you really don’t have that luxury.
 
#4 ·
for what it's worth, i was in you position with the engine about a year ago. I opted for the "do it yourself repair". ordered most of my parts from Rock Auto and saved a good bit of money. gasket set, new head bolts, machine work, timing chain kit (I had replaced the water pump a month prior) and all ran me about $1000, but I logged about 25 hours in the garage. whether that amount of time is worth the money savings is your call. I actually used a usb bore-scope to look down inside the spark plug hole and confirmed antifreeze sitting on top of the cylinder 8 piston. I took a couple dozen pictures and posted them online. if you would like, I'd be willing to share them with you.
best of luck
 
#5 ·
I wouldn't waste time on it. (I have been a Grand Cherokee owner of 3 different models over 20 years and currently have your year and engine).

Priorities would drive me here. I would sell both vehicles and lease or purchase two inexpensive, four door Toyotas. I believe they can be had for $139/month each.

http://www.toyota.com/deals/lease/

A ten year old Jeep even with a re manufactured engine is going to be a time and money drain and is great if you want a hobby. Think of your parts investment as a sunk cost. Keep the receipts as it may help in raising your selling price a few hundred dollars.

My guess is that you can get about $4,000 for the Jeep which would cover your down or first lease payments on new or newer vehicles.
 
#6 ·
We have been discussing selling the jeep. Part of replacing the engine was that we could sell it for slightly more, or increase our chances of selling it at all. It seems there are a lot of better options out there already if I were to list it with a bad head gasket. Unless you think I could get something decent for it in its current state...

Money really isn't an "issue" for us right now, we can afford whatever repair is needed, but we're cutting into the emergency fund a little so I don't want any of it wasted on a teardown that isn't needed. Just looking for the best, most reassuring bang-for-buck. If a repair is too risky, then a replacement it is. But if I know a repair will be fine, then we'll go for that and save some coin.
 
#7 ·
It can definitely be repaired and if you can pick up another car while you have the downtime on this car, that'd be the best bet. Not sure if this is your first, but in my first baby experience you won't be able to work on the car for a while though... lol. I just started being able to spend a Saturday here and there about 2 months after his birth.

I totally agree with RCS1300 though, if your miles driven a year permit a leased vehicle jump into one of those for cheap so you have a super reliable new car while fixing this one to sell it. With a blown headgasket you won't get much for it. Granted yours is in much better condition and maintained better than the 2004 I bought, but I picked that up for $550 with what I was told was a bad engine (145k miles). Just FYI.
 
#8 ·
Well, I drive a ton - across 3 states weekly for work (I was in my honda civic hybrid when it blew up, recently replaced that with a 2011 subaru outback) - but my wife has mostly been driving the jeep since it gets terrible mileage and she drives less. But even she is across town every day, it might be close on the lease mileage. Everything in me is against a lease, lol, though I never considered it for short term. Could be an option.

This will be my second kid, but first time cracking open an engine. Seems like all I would need is a torque wrench and the FSM. The wife is also nervous about me taking on such a big project, though she's in the nesting phase right now so take that with a grain of salt (a very small one, to be safe :)). I'm a mechanical engineer so I have no doubt I could figure it out. It's just the time commitment I'm a little afraid of. Well, that and the fact that I could blow it all up if I don't get the timing right. *gulp*

I'd hope to get about $2-3k out of the vehicle in it's current state to make it win out over fixing it and selling. I think I could get $6-7k if I replaced the engine or at least got it running well again. But maybe you can give some insight here, could be off a bit.
 
#9 ·
at least you've got 1 reliable vehicle at this point. that's comforting, however with you traveling that much, you don't want to leave your wife with an unreliable (or dismantled) vehicle. if you want to keep the jeep, I'd lean towards picking up something else in the interim. Like Hendrix9 mentioned, your time is about to become very limited. Once the second child arrives, the first (not sure how old) is going to need a mixture of 1 on 1 attention from both you and your wife and involvement with the new baby. I have 2 boys (6 and 2.5) and recently went through that. time would definitely be my number one concern here. that's where the leasing option has some appeal.
the job itself is not super difficult, just time consuming and requires a lot of patience. there are some specialty tools that would make it a lot easier, but you can get by without them. if you replace timing chain and gears, make sure you get the right set. http://www.**********.org/f196/difference-16t-vs-32-t-4-7-camshaft-teeth-36615.html
JTEC vs NGC might not be an issue in 05, but it was for my 04.
air tools are not a must, but definitely very helpful. plan on cutting off and replacing the exhaust flange bolts and nuts. as for setting the timing, pop the rocker arms off and don't put them back in until you are sure the timing is correct. roll the engine over slowly a couple times and double check all your timing marks, and you will be fine.
best of luck with the new addition and with the project if you choose to take it on.
 
#10 ·
Personally in your situation I would put two new head gaskets on it, have the heads checked for warpage/possible machining if/needed/possible and sell it... If its been overheated to the red 3 times those valve seats would worry me.

Another approach, if the heads arent warped you could have the valve seats replaced so that isnt an issue. Suppose even if they are warped if they are machinable you could still go this route. If you like the Jeep and can do it, thats another good option. I by all means wouldnt do ONLY two new head gaskets and keep it though.


what made the Jeep overheat 3 times? bad water pump?
 
#11 ·
Personally in your situation I would put two new head gaskets on it, have the heads checked for warpage/possible machining if/needed/possible and sell it... If its been overheated to the red 3 times those valve seats would worry me.

Another approach, if the heads arent warped you could have the valve seats replaced so that isnt an issue. Suppose even if they are warped if they are machinable you could still go this route. If you like the Jeep and can do it, thats another good option. I by all means wouldnt do ONLY two new head gaskets and keep it though.

what made the Jeep overheat 3 times? bad water pump?
No, it was the gasket. Air bubbles in the coolant line is my guess. It'll slowly creep up in temp as you're stuck in traffic or at a red light. Once you get moving, you can hear the coolant rushing through the heater core and it stays at proper temp while moving.
 
#13 ·
Personally, I believe that if you've never done this before then you don't have the tools to do this right. This lack adds up really fast. Add this to your budget and cuts into the patience quotent.
You certainly won't have the time to do the job yourself so you'll probably need someone else to do it. That will add cost as well.
I'll tell you a little secret. If you think "nesting" is an issue, wait until you are both sleep deprived and on the edge. Not pretty.
Cut your losses and sell it as is, lease a car for a few years and save your sanity.
I'm a mechanical Engineer as well but I've been at it for 45 years and have 5 grandsons. Learn from me.
 
#14 · (Edited)
Everyone seems to be getting hung up on doing the repair myself vs paying a shop. I appreciate the thoughts there; yes, I'm slightly considering doing it myself, but what I really want to know is which of the three options you would go with in my first post. I don't know the condition of the heads, so if I pay someone to tear it down to replace the gaskets, I might need to have new heads put in as well. Is this a suitable repair, or would there be other concerns in the lower half that justify a whole engine replacement? Or, would the cost difference between the head swap and engine replacement be small enough that it's worth the extra cost to do the whole engine swap? I guess I just don't know how easily these things break or cause future issues. Seems like fairly easy...

So far I hear 1 vote for a remanufactured engine swap, and 2 votes for paying a shop to replace gaskets / heads (but per my previous post I'm having difficulty finding a shop that's willing to do that). I'm really close to having a whole new engine put in and hoping to get $6-7k for it on craigslist. I'd still pocket ~$2k from that.
 
#16 ·
If your just going to sell it than why not either fix the gasket or drop a used motor in. The cost of a remanufactured engine will not show enough return to be worthwhile. Especially when there's still 150,000 miles on the rest of the drivetrain. If your gonna keep it for a long time than that's a different story.
 
#17 ·
My options seem to be:
1) tear it down, replace all gaskets. Machine heads if necessary (though I understand they only have about 2 thousanths of allowance for machining - either not much or none at all)
2) tear it down, replace all gaskets and both heads.
3) only tear down enough to replace engine with remanufactured engine.
4)
Better options:

1. Remove one head, machine that head, replace gasket. I would have the oil analyzed for $28 at Blackstone labs. If no coolant or minimal coolant is in it then I would go this route, if you have time, as it will be the least expensive in parts and require the least amount of your labor with the highest chance of success. If coolant is in the oil it is possible that the main bearings are damaged and option 1 would be a waste of time.
2. Replace engine with a similar engine. This is the second least expensive option only because the engine is less expensive than a re manufactured engine. Labor is the same as a re manufactured engine replacement. Probably good return on the dollar invested to get the vehicle running for resale.
3. Replace engine with a re manufactured engine. I would not go this route as the vehicle is 10 years old with over 100,000 miles and resale value will be low. This is an option that only makes sense if you plan to keep the vehicle for 5 years longer.
4. Sell it as an easy to complete project car. Line up the garage/mechanic and re manufactured engine for the potential buyer. Price the vehicle so that with the re manufactured engine it will be priced competitively with other vehicle options. All the buyer has to do is purchase the vehicle from you and have the local garage immediately install the re manufactured engine so they can drive it home.

I would recommend option 4 as it would be fun to set-up and probably a quicker sale. Plus, it would involve little to no effort on your part. The buyer gets a brand new re manufactured engine installed at a competitive used car price. You sell the Jeep quickly.
 
#18 ·
Ok, so after talking it over here with the wife and considering the advice in this thread, I decided to take it to a shop to get the head gaskets replaced. After calling about 6 or 7 places I finally found someone with staff who do engine tear-downs (it was harder than I thought - nobody wants a car hogging a spot in their garage that long). Along with the head gaskets, they're swapping out the whole gasket kit (obviously) - intakes, exhaust, etc etc - new head bolts, water pump, thermostat, spark plugs, oil change, oil filter, fluids. $2200. This includes machining both heads if necessary / possible. They will inspect timing chain tensioners (which don't seem to be an issue). I mentioned the timing chain guides are likely brittle and may need new ones of those, but they are readily available and pretty cheap, not a big deal. I don't envy them taking the exhaust manifold bolts off while trying to preserve the heads...

I specifically requested they check the valve seats - they said they'd do the valve seals if necessary. I don't know if I need to stress this more or what. I don't want it dropping a seat and causing all other kinds of damage like @nathanjaybar found in his fixer-upper. He said the extra machining on these might add ~$100 or so, which is fine by me.

Is there anything else I should bring up? I've heard lifters could go bad (gunked up at least), should I replace all of these? Seems like it could be easy for the next guy to replace those too, just pop open the valve cover. At least, it's not going to tear up my engine from the inside out if they go bad, just throw a rocker arm.

We are fixing the jeep to sell. But I'm an honest guy and I don't want to leave the next owner with a bunch of covered-up problems. I feel like the transmission and transfer case are good and worthy of a quality repair on the engine. When it comes back there's a couple other things I'd like to do myself like the airbag control module (have the intermittent airbag light on the instrument cluster), and the blower motor resistor (currently full-blast or off). Maybe a good detailing by me and it should be a nice vehicle for the next guy.
 
#19 ·
Is there anything else I should bring up?
If you are going to drop $2,200 I would send an engine oil sample to Blackstone Labs ($28 and four days) first to find out two things. First, is there a significant amount of coolant in the engine and second, is there a significant amount of metal from the bearings in the oil. If yes to either, I would replace the engine with a used one. Make sure you take a good sample to send.
 
#22 ·
Personally I have a spare vehicle to drive, the shop tools, and the time to do it...and I would still opt for a quality reman if I was certain I was keeping it. I doubt seriously that you would recoup your loss if you're selling it though. The only way to do that would be to rebuild using a quality machinist, keep all receipts, and prove you did it right and had the expertise to do it. If money isn't a problem you wouldn't be diving into an emergency fund when you have another car to drive. If you like it, keep it, drop a reman in it. It IS sunk money. I have a fantastic well maintained 2004 GC Overland loaded and meticulously maintained and I know even with the upgrades and maintenance I've done, the KBB book is not going to be exceeded. Pretty sure I'd be seeking a 5.7 in an 05 if I was a buyer too not a 4.7. Check KBB, check what your time and effort is worth, and do a sanity check. Mileage and condition will drive most of that financially. Just my two cents.
 
#23 · (Edited)
So KBB is ~$4700, but locally they're going for $6-7k right now (I'm assuming inflated value pre-winter). Even at KBB, and even if I replace the heads entirely, I'll still recoup the repair cost and pocket $1500 - worst case. Best case I get by with the $2200 repair and sell for $7k and pocket almost $4800. Either way, I'm in the black, so this makes sense to me. If I sell as-is, I'd have to deduct the repair cost from the sell price anyway, so my end result is the same. Except, having done the repair, selling a functional vehicle is more likely than one with major issues.

I agree, if I was keeping it, I'd strongly consider the reman (I was, even knowing I was going to sell anyway). But there's no telling whether it'll have another big issue or not. Considering all the other replaced parts on the vehicle already, a case could be made for the KBB price at a minimum. Also, most buyers are probably not the type to be a part of this forum. I'm not saying they're stupid (most people are probably smarter than me - ha), but they'll probably see it as a nice 4WD vehicle with a towing package that'll do great in the winter and comfortable to drive around. It had some major work done on it to get it running well again (including some opportune replacements that didn't have issues in a good faith attempt to do it right), and the parts that are left are understood to be 150,000mi "broken in." Like has been mentioned, it's a high-mileage vehicle and that comes with some risks no matter how you slice it.

I'll probably always be wondering if I made the right decision, but right now I'm pretty comfortable with this I think.
 
#26 ·
Well, you still need to take off both intakes (it's one piece), and fuel injectors on both sides (fuel rail is one piece anyway), and you're already taking everything off the front and 2/3 of the timing system (maybe all of it depending on which side is the bad side - which side is cylinder 8?). Maybe you can help me think through this, but if it heats up, wouldn't it be the whole engine? The coolant is what's being measured by the thermostat, correct? If there's an air bubble, it's the whole system that's not getting coolant, not just the one side with the bad gasket. So if it all heated up, I would want to check valve seats on each side, and each head has an equal chance of warping. Plus I've heard if one gasket goes the other isn't far behind, which may or may not be true.

So, it seems to me like if you just do one side, you would be saving some labor, but the majority of it is consumed by the teardown in general. I'm guessing maybe $2-300 (10-15%) in savings. If I'm being that tight, I might as well tell them to keep the existing water pump and thermostat too. It just seems to me like the incremental difference is worth it. If I was keeping the jeep, this is the way I'd go, and I'd like to be true to the next guy like that too.
 
#28 ·
Plus I've heard if one gasket goes the other isn't far behind, which may or may not be true.
Do not know about that one. Time saved in only doing one head - only one head has to be removed, only one exhaust manifold has to be removed, all of the wiring on the drivers side of the engine does not have to be unfastened and moved. Removing and installing the fuel rail, intake manifold, and cooling fan are very quick procedures.

Cylinder 8 is on the passenger side against the firewall. It is the easier of the two to get to mostly because there is less wiring on that side.

If $2,200 for entire job, my best guess is $1,500 for one bank/cylinder head. I might replace the thermostat and inspect the water pump. Bank two - with cylinder 8 - is a must repair, bank one is preventative maintenance. I would at least ask for an estimate so you have a basis for making the decision.
 
#27 ·
So it looks like if you're standing at the front of the car looking under the hood at the engine, cylinder 8 is the far back left. From some timing chain replacement photos, it looks like the left side is the far back gear in the timing system, so the right side timing chain would need to be removed to get at it. In other words, you'd have to take the whole timing system off to get at the left side gasket. I don't know if they could keep the right side timing chain on the cam sprocket - if so, it may save a bit more labor - but if not, they have to open up both heads anyways and at that point the only difference is the exhaust manifold and head bolts on the one side, really not much at all.

firing order: http://i207.photobucket.com/albums/bb300/acoustiktonz/47.jpg

timing chains photo: http://www.ebay.com/itm/DODGE-JEEP-...NE-YEAR-WARRANTY-/172196933525?fits=Make:Jeep
 
#29 ·
I disagree. Doing one head vs 2 on this engine can't be much of a price difference. Having one torn down right now in my driveway is my only experience. I don't really know how shops really charge stuff.

All the timing stuff has to come out regardless if you do 1 head or 2, so it's really just the difference of unbolting the exhaust manifold from the y pipe and unbolting the head, cleaning/machining the head and reinstall.

Also for what it's worth both mine were shot. Not saying yours is the same though. Also the passenger side is the hard side, all the AC crap in the way that you can't remove unless you want to evac the system.
 
#30 ·
Also the passenger side is the hard side, all the AC crap in the way that you can't remove unless you want to evac the system.
I had the opposite impression when I put in new exhaust manifolds, valve cover gaskets, and lash adjusters. I took off the AC compressor and moved it to the side with lines still pressurized.

Not saying there is a big savings there but every $700 counts.
 
#31 ·
Here's another option too. You could see if your area has one of those rent-to-own car lots. Where I'm at, there are 2 & it's exactly as it sounds. You put a down-payment (amount depends on vehicle you'd rent) & pay twice a month for the car/truck you get. EVERYTHING is covered in your payments, personal property (if your state has it), sales tax, a warranty is included with free oil changes, etc (not really free since you're paying for all of this stuff to them through your payments but I digress). At any time, if you decide you don't want or even need the car anymore, you can return it with no penalty. Of course, there is a standard mileage restriction for how much you can put on the car per year such as with leased cars but it's 15k miles/yr. You can add more if you do more than that. Good luck.
 
#32 ·
@jamsomito, having just done what you're doing to your Jeep, personally I think it's a good idea to replace both head gaskets like you're doing. When the mechanic has gone that deep in to the engine, you might as well do some preventative maintenance while you're in there and (potentially) save yourself a little money in the process. I don't know how much weight that idea of "if one goes, the other isn't far behind" holds, but it's not a bad way to think. Mine were showing equal signs of wear and were on the way out. The last thing you want is to try and save $700 by only doing one head gasket now, then have to spend another $2,000 to dive all the way back in and replace the second head gasket when it fails 6 months - a year - whatever - down the road.

I give you credit for wanting to do this the "right" way with the intention of selling the Jeep. A lot of people would throw a bandaid on it, sell it, and have the "it's not my problem any more" mentality. I would appreciate the extra effort on the buyers side for sure.
 
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