I have had a slight miss for several months now, that I could never correct no matter what I replaced,cleaned,etc. I could not have done most of the repairs nor gotten the ideas had it not been for " YOU GUYS" and the site itself. So a big Thank You, to all of you contributing your problems and solvers, you don't know how much this means to an unexpierenced mechanic.
Allright, now to get on with it, the miss has become pretty constant and I did a compression test with one cylinder showing hardly nothing. If you are facing the motor at front of truck, it is the right side(Driver side) and the furtherest one back, easier to say it's the one clear to the back of motor. All the others seemed to be OK! I did not do this alone my local mechanic/friend moreless did it and I watched. He says burnt valve on that cylinder.
My questions are, although the truck runs but misses and hesitates unless under constant fuel(like interstate driving)should I park it? Do I do a rebuild on top end to just have the bottom end let me down? Do a valve job on all valves or just reseat that one valve? Is this the sure problem,not something else? Find a used motor? Get full coverage insurance and burn the piece of S#@$? Sorry, Im just depressed, I've had 3 back surgery w/ no income and not working for over a year and my wife has to support us all and now this!! Just want to lean towards the right direction in decisions on this vehicle.
Im in NO means a sharp mechanic, but I can do some and especially with the help of many friends. I just would like several opinions before doing the wrong thing. HELP, in West Virginia--Thanks

Unfortunately, that is almost sure the problem. The back cylinders burn valves because of the exhaust crossover heat. I you tear it down to fix it, you definitely want to remove both heads and have both heads checked and the valves ground. It is a big job, I don't think I would recommend most non-mechanics do it. I just finished mine in November and it's a pain, and I am a full time mechanic.
It also is fairly expensive, if you have the machine shop adjust the valves, you are looking at about $600 just for the machine shop. If you adjust the valves yourself you can save a couple hundred, but will probably have to spend a hundred for valve shims.
If you try to do it yourself, you will probably get very frustrated halfway through, it is not a fun job. Hate to be the bearer of bad news, but that's the way it is. I'm not recommending any particular course of action, just telling you my experience.

Thanks Toyo!! I do have a friend who's dad owns a machine shop and he works daily for him, so I will be getting a nice price break, thank goodness!! Now, is it worth doing ? Is the bottom end going to hold up? Or a chance worth taking? I have 155,000 miles on this 2nd motor, but its a hell of a nice truck! 4" lift 35x12.50 on Mikey Thompson baja claws, Mickey 15x10 rims, Skyjacker suspension system,and much more! OH, did I tell you it looks like Paris Hilton, but runs like one-legged man in @ss whoopin contest <img src="/forums/images/graemlins/lol.gif" alt="" /> Anymore replies will help, so THANKS!!

3.0 has a great bottom end. I woult take a look at it when you have the heads off. If everything looks good then leave it alone.

Be sure to use a good quality gasket set from engnbldr. You won't regret that.

What kind of miss are you having? I'm just curious, because just today my truck started to have a strange miss. Once you get up to speed you dont really notice it. Seems to rev fine in the higher RPM's, but at load at lower RPM's like when starting in 1st gear, you can really feel the miss. I'm hoping my problem just requires a tune up. Thanks!

Seen this same problem your having with the miss and 1st gear somewhere along my internet search using Google and typing in," 3.0 FZE V6 Rebuild" but not to worry it was an easier job than a burnt valve. Not sure if this is the same as your miss, but man TYPE different SEARCH ways to troubleshoot your problem and I know for sure they had identified the problem and it recalls to me as nothing major I believe. If you do not have any luck reply back and I will give you the direct website w/troubleshooting ! OH, By the way thanks for your concern and If I can be of any help, I will give it my all--Dirtybeerguy!! GOODLUCK

Your problem sounds similar to what was diagnosed as my second burnt valve in 6 yrs. IMO the engine is worth rebuilding, a well maintained borrom end is usually good for 2-300k, and since it sounds like money is tigh an engine swap is not an option. Unfortunately you really wont know for sure that it is burnt valve until you pull the heads.

To rebuild it it, pull both heads and have them reworked, you don't want to do just one. I had both of mine rebuilt and valves adjusted including new headbolts(mandatory for the 3.0), for about $550 two yrs ago, yours should be cheaper since you have access to a machine shop. You will also need a new knock sensor and knock sensor wire(also mandatory on the 3.0), you will want to have the injectors cleaned and rebuilt, a new timing belt, water pump is fine unless it is leaking(or you can replace for peace of mind), and a complete engine gasket kit. Depending on prices where you live this should run under $1000. To avoid another burnt valve and to increase performance, I installed a set of Downey headers, a new cat and muffler. Along with some misc. stuff my rebuild came in around $2k. No one can say for sure that burnt valves/hg failure is caused by the oem x-over and exhaust manifold design, but with it so common on this engine it seams like a possibility, especiall since #5 &#6 are common burnt valves.

I had never taken on an auto rebuild as involved as the 3.0 before, and it seams a lot more daunting than it really was, you just have to take your time in the pull down stage. I made a drawing, took pics and video of everything as I tore it down. It took about 3 days to tear it down, but the time was worth it since I had plenty of reference material for the rebuild, all those vaccum lines can be a PITA.

Also you can install the heads complete i.e., with the head bolts already in place, the cam installed and the valves already adjusted, there is enough room to get a socket onto the headbolts with the cams in place and still get the proper torque setting, you have to buy a slim socket to do it though. This will save you the hassel of trying to adjust the valves yourself, or towing/driving the rig to a shop to have them do it. I was able to do my rebuild w/o a factor manual by buying a haynes to go along with my chilton's, before startying yours, download the FSM manual from this forum, it would have been nice to have it when I did my rebuild.

Ditto, bottom end should not be worn out if it was maintained.

You can do a leak down test and see where air is leaking. That will narrow down the problem without removing the heads.

Thanks to the both of you guys for your input! I myself do have the Haynes model and do plan to draw, video,etc. I will be asking some questions from time to time soon as I get started so PLEASE stay tuned!! I had surgeory not long ago so bending or geting in any awkward positions right now won't work. Also, I recently put a fan idler bracket on this motor( We all know about this fun job)if you got the 3.0, and while doing so I replaced water-pump,timing belt,and new valve pan gasket. Do you have any suggestions on where to purchase a complete Header Set at an affordable price? My biggest question is, driving the vehicle 6-7 miles every other day going to do damage? My wife drives the 4-Runner to work and I must go to rehabilitation twice a week? I'm sure it is not good for it, but it is my only other means of transportation. Thanks again

Well I don't know for sure but I can't see it being especially good to keep driving it as is. It goes without saying that you should have it done asap. The fact that one cyl is dead means that there is more strain on the rest of the engine. Pulling the engine and rebuilding it can be a bit labor intensive so I would find a good friend who will do the ***** work for ya.

I'd take the cam sprockets off with the engine still in if you can, they take a lot of work. Just a pit of FYI.