Fix head gasket or put in new engine?

[quote:ca3b396dec="puddledive"]I have a 2001 Jeep Cherokee sport with 118,000 miles on it. First, I can hear a grinding metal sound sometimes when I reverse, somewhere near the back of the car. Could this be the transmission or a u-joint going? Second, after my car overheated last week my mechanic said I have a cracked head gasket, possibly a cracked head, and possibly a cracked block. (The last two are possibles, because he hasn't taken everything apart yet.)
He quoted me a price of $950 to fix the head gasket, $1500 range to replace the head and gasket, and somewhere in the $2000-$2500 range to replace the head, gasket, and block. Are these prices reasonable or am I getting ripped off?
Should I do this or put a new engine in with lower miles? I found an engine from a 2000 Cherokee with 400 miles on it and a 6-month guarantee from a salvage yard for $1000. My mechanic said he could put it in for $5-600. They got the engine in 2002, I guess from a totaled car, so it's been sitting for five years. Is this bad that it's been sitting? So, for the same price of fixing the head and gasket on an engine with 118,000 miles should I completely replace it for one with 400 miles on it?[/quote:ca3b396dec]

Hey puddle,
You can't really assess your options until the engine is disassembled. I would not recommend a used engine that has sat for 5 yrs either! I would recommend getting the head work done, and be prepared for a cracked head, just in case. the noise in the rear could be a u-joint, but also could be the rear differential too. I would have to recommend a good diagnosis on that one.( by your tech) Let us know!

Chris

A few years back, my 90 Jeep Cherokee had a head gasket problem which was repaired by the professionals. In two days of light driving, I was back in the garage with an overheating engine. Reason: they didn't see the crack in the block. Solution: I bought a reconditioned engine which has been perfect ever since. I wouldn't touch the 5 year old engine because it has to be disassembled to restore it properly (bearings, oil ports etc are all jammed up with rust and corrosion).
Get your original engine disassembled and do non-destructive tests with dye penetrant (spray and black light) to determine if your block is okay. If so, do the head gasket replacement, and while you're doing it, shave the head to ensure it's flat. Also, replace all your sensors while the engine is apart. Good luck.

[quote:79482d500b="Tony90"]A few years back, my 90 Jeep Cherokee had a head gasket problem which was repaired by the professionals. In two days of light driving, I was back in the garage with an overheating engine. Reason: they didn't see the crack in the block. Solution: I bought a reconditioned engine which has been perfect ever since. I wouldn't touch the 5 year old engine because it has to be disassembled to restore it properly (bearings, oil ports etc are all jammed up with rust and corrosion).
Get your original engine disassembled and do non-destructive tests with dye penetrant (spray and black light) to determine if your block is okay. If so, do the head gasket replacement, and while you're doing it, shave the head to ensure it's flat. Also, replace all your sensors while the engine is apart. Good luck.[/quote:79482d500b]

Good advice Tony! Though I have to question the "Change all your sensors" portion ...... the only sensors I would recommend would be the O2's (due to coolant contamination), if the "others" worked fine prior, why change them? Seems like a needless expense. If it ain't broke ...... you know the rest!
You can only take Preventative Maint. so far! IMO.

Chris

[quote:94b6f08d9c="Tony90"]A few years back, my 90 Jeep Cherokee had a head gasket problem which was repaired by the professionals. In two days of light driving, I was back in the garage with an overheating engine. Reason: they didn't see the crack in the block. Solution: I bought a reconditioned engine which has been perfect ever since. I wouldn't touch the 5 year old engine because it has to be disassembled to restore it properly (bearings, oil ports etc are all jammed up with rust and corrosion).
Get your original engine disassembled and do non-destructive tests with dye penetrant (spray and black light) to determine if your block is okay. If so, do the head gasket replacement, and while you're doing it, shave the head to ensure it's flat. Also, replace all your sensors while the engine is apart. Good luck.[/quote:94b6f08d9c]



Replace all your sensor?? :shock: :? :roll:

That is like throwing the baby out with the bath water.!

I have yet to see a cracked block, not saying it isn't possible. Magnaflux will not pick up a crack if it isn't exposed on a visable surface.


I don't know that I would be afraid of the used motor. With a 6 month warranty if there was going to be a problem it would surface by then I would expect.

Here's the thing: what exactly is the warrranty. If this thing is lunch right from the get go: Who pays for the labor to do it again? and a what labor rate, and anything additional? What is going to replace htat engine? Do they have another ? The what if it is bad is the thing you need to determine on that route.