Hi Friends, I have a 00 LTD XJ that yesterday was diagnosed with a broken valve spring and mangled push rod. This happened at about 40mph, much rattling and misfiring. I was able to safely get off the highway where it stalled and coasted into a parking space. It was towed to the shop where they removed the valve cover to find the broken spring and rod.



He said that the retainer clip, extension rod, and part of the rod is still missing, but said that they won't know for sure unless they pull the head.

He said labor only to R&R the head is $800. Not counting seals & fluids.

Also more $$ to replace all push rods and springs. And whatever else has gone wrong.

new clearwater or windy city head with shipping: ~600
labor to r & r head: ~800
valve springs ~20 each: ~240
push rods & stuff: ~70
more labor and stuff: ~800

Comes up to ~$2500 + tax & tip if lucky.

I bought the jeep new. Now with ~180k miles it is in decent condition except that the AC does not work. In the last 2 years it has new tires, alternator, battery, radiator, temp & pressure sensors.

Do you guys think that I should pay for them to pull the head and check for metal debris in the engine?
If the engine block is ok would it make sense to just put on the one new spring and rod & take my chances?
The tech said that all the springs and rods should be replaced while its being done.

My gut feeling is to cut my losses now. What do you think?

 

Tough call, unless you could do the work yourself or had a knowledgeable Jeep handyman available.

Sorry, but your Jeep is probably not worth much without repairing it first.

 

There's a decent chance that valve is bent also. Cheap fix if you can wait a week or more. Pull head. Have it redone at a good machine shop and put it back together. You should only need the valve and spring in question. The machine shop can tell you what it needs. I'd highly recommend machine shop do a valve job. Should be good as new.

 

If that valve is bent, chances are it hit the piston, or I should say the piston hit it! Pull the valve up and hold it closed. Is it the same height as the others? Pressurize that cylinder with air. Does it seal?

A Clearwater head comes with all new valves and springs. IMHO all you'd need is one rocker and pushrod if the piston is okay. There's a company that sells reconditioned TUPY heads cheaper than Clearwater, but IDK if they come with valves and springs.

In April of 2015, I bought a Clearwater head for $455 complete with shipping both ways (core return) and had it in 4 days because they have a warehouse here in NY. From what I can tell is they no longer sell direct, but you can call them. 800-572-1963 Odessa Cylinder Heads

 

The most common cause of a bent push rod is a stuck lifter . I’ve seen several Cherokees being sold for parts due to rust or bad transmission or rear end for less than 500 bucks lately . 800 to R and R the head is too high. There’s several options you could take here but now might be a good time to learn some hands on work yourself or phone a friend .

 

In the thread on cracked cylinder heads where the thread starter first posted the problem it was mentioned that they do not have the space or ability to tackle this job on their own. Cost is also a consideration.

I like the suggestions by dave1123 on checking the valve for damage and pressurizing that cylinder to check for excessive leakage. I am wondering if it would be worthwhile and cost effective to first have the oil pan pulled to see what is in there. Confirming if any debris such as part of a piston and missing valve retainers is present or not might be a low cost approach in helping to determining a go forward plan. What does everyone think? Can you drop the oil pan on a 2000 quickly? Keep in mind a shop charging $100/hr or whatever for labor is involved. I expect they might charge a couple of hours to just pull the head and evaluate so I would hold off on that for now.

In this case I believe the broken spring is the cause of the bent pushrod, not a stuck lifter. As cost is a driver in this case I would not immediately jump to all new springs unless this engine has been driven hard and run to high RPM’s frequently. Spring failures are more common in high reving applications due to fatigue or poor design for the application. I don’t recall hearing of chronic spring problems with stock Jeep 4.0 engines. A manufacturing problem, handling damage or corrosion (potentially due to leaking coolant into the valve cover area?) can lead to premature spring failure.

Katherinego: is the shop giving you any recommendations on how to proceed? Had the engine been making any unusual noises prior to the incident? Tapping, clicking, sluggish acceleration?

 

 

Slightly off track but I want to understand your view on the stuck lifter item: Is the 4.0 an interference engine related to valve-to-piston clearance? i.e. Can the piston hit the valve if the valve is in the normally open condition? I did not think that was possible for the 4.0. If the timing chain fails or stretches I don’t think the valves get hit. If it is not an interference engine I don't see where you get the force with a lifter stuck in the "up" condition to bend the pushrod. A normally intact valve could not be pushed up against a rising or stuck lifter by anything other than normal spring force. On an interference engine, yes that could happen. If I am missing something I want to understand.

Maybe what happened here is that the valve retainer clips came off and the valve then dropped down and contacted the piston. You will also note that one end of the pushrod is mangled as if it got out from under the rocker and scrapped against it or the adjacent valve assembly.

 

edit..I gave an incorrect link before, the 4.0 motor is apparently non-interference

 

Junkyard. Lots of 4.0s around here. 129.99 plus a 25 dollar core.

 

 

I think we're missing the point about the 4.0 being a non-interference engine. That's providing the valve is still retained by it's spring and retainer. If it's not, it can drop down farther than that and can get hit by the piston. Whatever happened, I'd say the head has to come off anyway. Where is the retainer? What happened to the rocker?

 

You're right, unless it has great sentimental value no reason to dump anywhere close to that amount into a vehicle that's 18 years old.
List it on E-bay stating it needs an engine start the auction at 99¢ and see what you end up with.

 

Here in the salt belt, structural integrity is the criteria that has to be looked at. If it's not rusted and the drivetrain has been taken care of it's worth putting money into it. If you live in the south or west where good ones are easy to find, don't waste your money trying to fix it.

 

I listened to y'all and talked it through with my master mechanic friend last night. Though I bought it new I don't have a lot of sentimental attachment to it. In fact I have wanted a newer car with working AC for a loooooong time. . I am lucky to live where I can walk or bus to most everything so I am not in a rush to do anything. I am having it towed home today and will list it on craisglist or ebay. The neighbors will let me put it on the end of our shared dead end for now.

There is no rust, the body is straight, it's the LTD version with leather interior plus towing and winter packages ~180k on the odo. Do you think I can get $1000 out of it?