What does it typically cost to replace a timing chain?

May I ask what symptoms directed the mechanic to.make the timing chain diagnosis?
I’ve had the Jeep about 1 1/2 year, check engine light came on after 3 months.

At about 24-26k Rpms the Jeep would buck and drive really rough..

Read cam sensor, replaced with Mopar.
Jeep ran for about couple of months and same code came up mechanic replaced crank sensor with Mopar sensor..
About a month after that engine light back on took back to mechanic and he said there was a short in one of the cam sensor wiring and replaced...
About 3 months after that ch eng light again and same code... the strange thing was that if outside temp was below 50• then the check engine light would come on and start bucking at 26k rpms...
Now took Jeep to the Dealership, they said both sensors were bad and replaced both.
Very next day engine light on again, they suggested that it needs new computer...
I sent computer out for repair, the company called and said they cannot find anything wrong with computer. They even left the computer in the refrigerator freezer overnight and retested unit, and same results, no issues with the computer.
Re-installed computer and the engine light stays on constantly but now it only bucks at 34k rpms....
Since it’s my daily driver, I drove it always under 34k rpms...
On extremely hot days 98• and above the car
At times, the car would shut off and have a really tough time starting and when it does start it runs really rough, like out of timing. If I let the car sit for an hour it starts right up and drives pretty normal.
That shutting of happened 3 times within 3 Month span...
Last week the Jeep kept shutting off about every 10 blocks and having a tough time starting and once started running very rough...
 
I’ve had the Jeep about 1 1/2 year, check engine light came on after 3 months.

At about 24-26k Rpms the Jeep would buck and drive really rough..

Read cam sensor, replaced with Mopar.
Jeep ran for about couple of months and same code came up mechanic replaced crank sensor with Mopar sensor..
About a month after that engine light back on took back to mechanic and he said there was a short in one of the cam sensor wiring and replaced...
About 3 months after that ch eng light again and same code... the strange thing was that if outside temp was below 50• then the check engine light would come on and start bucking at 26k rpms...
Now took Jeep to the Dealership, they said both sensors were bad and replaced both.
Very next day engine light on again, they suggested that it needs new computer...
I sent computer out for repair, the company called and said they cannot find anything wrong with computer. They even left the computer in the refrigerator freezer overnight and retested unit, and same results, no issues with the computer.
Re-installed computer and the engine light stays on constantly but now it only bucks at 34k rpms....
Since it’s my daily driver, I drove it always under 34k rpms...
On extremely hot days 98• and above the car
At times, the car would shut off and have a really tough time starting and when it does start it runs really rough, like out of timing. If I let the car sit for an hour it starts right up and drives pretty normal.
That shutting of happened 3 times within 3 Month span...
Last week the Jeep kept shutting off about every 10 blocks and having a tough time starting and once started running very rough...
I’ve had the Jeep about 1 1/2 year, check engine light came on after 3 months.

At about 24-26k Rpms the Jeep would buck and drive really rough..

Read cam sensor, replaced with Mopar.
Jeep ran for about couple of months and same code came up mechanic replaced crank sensor with Mopar sensor..
About a month after that engine light back on took back to mechanic and he said there was a short in one of the cam sensor wiring and replaced...
About 3 months after that ch eng light again and same code... the strange thing was that if outside temp was below 50• then the check engine light would come on and start bucking at 26k rpms...
Now took Jeep to the Dealership, they said both sensors were bad and replaced both.
Very next day engine light on again, they suggested that it needs new computer...
I sent computer out for repair, the company called and said they cannot find anything wrong with computer. They even left the computer in the refrigerator freezer overnight and retested unit, and same results, no issues with the computer.
Re-installed computer and the engine light stays on constantly but now it only bucks at 34k rpms....
Since it’s my daily driver, I drove it always under 34k rpms...
On extremely hot days 98• and above the car
At times, the car would shut off and have a really tough time starting and when it does start it runs really rough, like out of timing. If I let the car sit for an hour it starts right up and drives pretty normal.
That shutting of happened 3 times within 3 Month span...
Last week the Jeep kept shutting off about every 10 blocks and having a tough time starting and once started running very rough...
 
Is it throwing any new codes at all when it shuts off?
If the PCM checks out and if the camshaft and crankshaft sensors installed are both Mopar, (they absolutely must be Mopar) then im at a loss until your engine can give us some direction to troubleshoot.

Last week my 05 CEL came on. AutoZone checked it and found code 0431.
When I did the on/off ignition trick, I got a different, more specific engine code which defined the problem.

Try the on/off key trick and see if it throws any new codes.
 
I've worked at a Chrysler/Jeep dealership for many years and for Jeep before Chrysler took over and I've never sold a timing chain for the 4.0 or the 2.5 engines.
 
With that code and it being off by 17* I don't know how the timing set could not be the problem. Unless someone was in there before you bought it and set it up wrong , the only way it could change it's self is by jumping by being too stretched/worn. Either way it should be inspected. I mentioned timed replacement earlier and that was shot down pretty quick, the reason I mentioned it was not mistaking it for a rubber belt but that I've owned other mopar vehicles that did have a 100,000 mile replacement on the timing Chain. It was an 05 Intrepid with the 2.7, yes different engine in every aspect. My research has not found anything yet on the 4.0 but all the maintenance schedules I've found end at 120,000 and also seem to be very anemic my Yamaha Wr250r has a more complex schedule.
 
I have learned a long time ago. Anything is possible.

If you are mechanically inclined. You can always inspect it yourself. Before you buy a new one.

If not you are at the mercy of the shop to be honest.
 
That makes some sense, if the chain/gears are worn it would cause rough running and the other symptoms.

Have you tried the on/off 3x ignition key trick yourself?

If not, do that now to see if there are any other codes displayed.
 
By itself, a stretched chain does not change the timing or alignment. A stretched chain can make noise but unless it is loose enough so it jumped a cog on one of the two gears, it won't affect the timing. That you confirmed your engine runs ok once in a while says the chain hasn't jumped a cog. If it had the engine would run roughly 100% of the time. I am not convinced it's a chain problem.
 
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By itself, a stretched chain does not change the timing or alignment. A stretched chain can make noise but unless it has jumped a cog on one of the two gears, it won't affect the timing. That you confirmed your engine runs ok once in a while says the chain hasn't jumped a cog. If it had the engine would run roughly 100% of the time. I am not convinced it's a chain problem.
Jerry is right, I misspoke.
I confused timing chain with timing belt.... ugh, mechanics dyslexia :/
 
Side note, my jeep is manual transmission and I believe that contributes to chain stretch, an auto trans absorbs drivetrain shock and doesn't have as much engine compression braking. I could be wrong about that, but it makes sense to me.
The timing chain is just between the crank and the cam, it isn't subject to drivetrain loading. The chain I can see being affected by drivetrain shock is the one inside the transfer case. :)
 
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Yes, a stretched timing chain will affect timing, it has to, there is more slack therefore more "time" from crank at TDC to cam at TDC.

You can check chain slop by removing valve cover, setting crank to TDC in direction of rotation(or make yout own marks), then watch cam as you then rotate engine in opposite direction until cam just moves, that's the amount of play.
 
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