So I have concluded, well actually the mechanic did, that my misfire and DTC p0301 is due to a burnt exhaust valve and common from what I've read. So i have narrowed it down to a couple of options and any input would help out and i Thank you guys in advance. Option one, just order a replacement cylinder head and replace. Relatively cheap and easier than pulling the whole engine. option two, get the entire engine rebuilt. More expensive but its giving new life to my xj. Keep in mind there is 225K miles on the clock so I'm not sure how much longer the bottom end of the engine is going to last. But the mechanic did mention that most cylinders did have compression within spec minus the number one.

 

I guess what I am looking for is any opinions on replacing just the head now and later one rebuilding the bottom end and reusing the top end a few tens of thousands miles down the road or how ever long it lasts. thanks again

 

Cheapest would be to take off the head yourself and take it to a machine shop.

 

Take it off and take it to a machine shop. Unless its a 2000 or 2001 because those are the years where the heads love to crack due to a bad production mold. In that case I would buy a new aftermarket.

 

Yea its a 1997 so I'm not exactly worried about a cracked head. I guess what I'm looking for is any advice against a top end rebuild with a 225k bottom end

 

Usually failure of the bottom end results in catastrophic damage to the engine block.

 

You can buy a ready to go reman'd head for less than $400. That's the route I like go. I am in the middle of a whole engine swap/rebuild and regretting it right now.

 

Why not send the head to the machine shop and have them rebuild it. Meaning a valve job. Ive done this on dozens of engines with good results. Often $250-$400 depending on the amount of work needed. Usaully 3-5 day turn around. Add a head set and your good to go.

Ron

 

Honestly the top end rebuild or reman is the only option i can afford right now. It just depends on which will be the minimal down time, and its looking like buying a reman will be the way to go. I was just worried about the bottom end not lasting very long after. Is there a way to check how worn the piston rings are? excessive blow by?

 

You can look for scaring when you have the head off. I personally wouldn't worry about it. Buddy of mine DDed and still wheeled his with rod knock for about 15k miles trying to blow up the motor before he finally said screw it and swapped in the other motor he had sitting around. His cylinders were scarred badly and his number 2 rod bearing was just about gone and she still ran. Only reason he finally said screw it and did the swap was because he failed smog for bad gas tank vapor return lines. Didn't make sense to fix all the lines and not swap the motor he's had ready at that point

 

Allied motor parts has a reman 7120 head for 280, plus 50 core deposit

 

That's a dang good price. How reputable is Allied?

 

My father and his peeps have used them countless times, without disappointment.