valve spring question
 

I have a 97 grand cherokee 4.0L and I need to replace some valve springs.


Can I replace them with out removing the head? I found one video that shows how to do this but the motor was a 4.0L from 2002 or 2003 and Im unsure if its going to be the same deal


Does anyone have any info or suggestions?

Do it one cylinder at a time, Get or make an air fitting adapter to go in the spark plug hole and put air to it to keep the valves closed. remove the rocker arms and compress the springs and remove the clips. Swap out the springs and put everything back together, then move on to the next cylinder.
I saw your other post, and I think It's doubtful that valve springs are your issue. I would replace the coil, as some mopar coils had an issue that would cause them to occasionally fail to fire, I have only had that issue with the v8, but I would still start there. Also, I would either buy a scanner and scan it myself, or take it to a mechanic with one and have it scanned. I'm not putting down the parts store guys, but most of them are barely capable of an oil change, let alone complex diagnostics beyond what their computer tells them. A code does not necessarily show the problem. Case in point, my buddy's 94 grand with the 4.0 died. I pulled the codes, and it said bad cam sensor. He was getting intermittent spark, out of time. after opening up the distributor and finding nothing wrong, we tried a few things and figured out that he had stripped all of the teeth off of the distributor drive fear.
Your issue could be as simple as something occasionally interfering with the cam sensor, moisture in your cap, corrosion somewhere on the cap, or a bad spot in one of the wires on the coil or cam sensor.
You will benefit from the new valve springs, but there is a good chance that they are not the issue. The most important thing about diagnosing an issue is remembering that you should always try and for sure identify a problem before fixing it. Otherwise you can end up just throwing parts and money at something without fixing the issue.
Just my 2 cents,

Thanks for all that...

5 years ago the jeep was classified as a "dying jeep"... everything was replaced outside of the motor and it all came down to the wiring harnesses needing to be repinned because of corrosion. they also found broken wires and replaced those also. The jeep ran perfectly for about three years and then I started getting some bucking and surging while driving and then slowly started replacing everything again.

The cap, botton, wires, plugs, coil, all my throttle body sensors, pick up coil, crank sensor, battery, starter, and alternator are all new. Less than 3k miles on all of them

When I get the bucking effect while Im driving I have been hearing this tiny little noise that I can only describe as this; imagine holding a tamborine very still and then lightly striking it with a drum stick one time almost like a tap. that tiny noise that it makes is what I hear when it bucks. I saw a video of some valve springs replacement and the guy was messing with the rocker arms showing how the springs have failed and I realized thats the noise Im hearing.

This motor is about to turn 300k and has had no real engine work ever done to it. I usually only go to the auto place for the code and trouble shoot the rest myself, however this is the first time the codes have ever pointed to the motor. Something is off with the driving. I have a new timing chain and sprockets on the way with springs, rods, lifters and the seals. Should I buy new keepers or do you think the ones in there will be fine?

Your keepers should be fine, but if you are going to go to the effort and expense and effort of changing the springs the few dollars it will cost are well worth replacing them.
one thing you should do before you order your parts is take the valve cover off and start the engine and make sure all of the rockers are getting oil. If not it may be worth swapping in new push rods while you're in there. It's normally not a good idea to swap in new valve train components like that, but with 300k on your engine I doubt it will do anything besides improve oiling.
It's up to you, but I don't think I would go as far as pulling the head to do a cam and lifters, with as many miles as you have on it an engine swap will be about the same amount of work and will get you way better results.

I did the oil seals on a 4.3 V6 chevy by feeding nylon rope into the cylinders then rotating the block up to compress the rope against the valves. Worked ok. How is the miles per gallon? If you are sputtering on start up and getting bad mileage, look at the front o2 sensor (b1s1). If unsure, unplug it and see if it drives any better. Mine did, so sensor is on order.