CaptJohn

I am still dealing with a low compression issue on the 2 center cylinders of my 3.slow. What I found when I pulled the Injection plenum was a huge mouse nest. Big enough to have created a hot spot, this thing was deep...ugg. So I checked the valve clearances and found both center cylinder exh valves to be too tight to get any feeler gauge in. I need to get the tool to compress the valves, get the spacers out, or make one? anyone tried that? Big question, on an engine like the 3.0 what is the likely hood that with 53K miles on the motor, those exh valves are tuliped? I have 85 psi on left bank, 125 psi on the right bank, all others are 185 psi. Thanks for taking the time to reply. Knee deep in it in NH John

abecedarian

I'm thinking you may be better off pulling the cams. There isn't an easy way to suck the valves down enough to allow you to remove the shims.

904_runner

Are you sure you are measuring them correctly.

There is a certain process you have to go through to make sure.
Are you using a manual.

I recommend the FSM.

CaptJohn

Yes, Cam lobes straight up, not off to the side. I am not so concerned with TDC because if the lobe on the cam is straight up, whats the diff?

abecedarian

point made- if the lobe apex is 180 off the follower and the follower is still in contact with the lobe, who gives a fart? there is no clearance.

/me guides 904_runner back to his cell.

scope103

You need to get the tool (like this http://ehardware77.ecrater.com/product.php?pid=3035742). Trying to use a pair of pliers or a small screwdriver or anything else is just asking for heartbreak.

GSGALLANT

That's what I have... works awesome.

OutlawMike

I have both of those tools, and neither is really worth buying.

I have done this on my 3.0 several times and on friends because they know that I know how to do it. It costs them beer, but I think they end up on the good side of the deal.

What have found that works very well is a hex key, a wand magnet, and a small screwdriver.

I believe the size that works best is a 3/16" hex key. Play around with the size. Slide the short leg of the allen in between the cast portion of the camshaft and the outer lip of the lifter bucket. The shim is captured inside of this lip. You can then rotate the hex key down by pushing on the long leg. This will push the lifter bucket down enough to use the small flat blade screwdriver to carefully pop the ship up to break the oil surface tension. You then use the wand magnet to get the shim out. There is a trick to where to place the allen key so that you can still get the shim out, but once you do it a few times you will be able to pop them out in seconds.

Only do one valve at a time, do not mix up the shims and get confused.

Of course, you need to first measure your clearance before taking out the shim. If you cannot get a measurement, then you may have to iterate. Maybe buy a shim that would put you at the biggest clearance allowed assuming that you are just touching the cam lobe and hope that there is a little pre-load and that you end up back in the middle of the range. The shims are spendy at the dealer, so you don't want to buy a bunch of them. I have also swapped shims between valves to get mid range clearances, funny how that works out sometimes.

Pulling the cams would be a hassle. You would have to measure all of the valves, but you cannot measure two of them ,right? Then you would remove the cam, replace shims, replace the cam, and re-measure, repeat as necessary, and then put a the timing belt, etc back on. If you are only doing a valve adjustment, that is a lot more work.

If you have a boneyard in the area like a Pick-N-Pull, you might be able to collect some shims for cheap. No telling if they are the right thickness, but I pick them up when I see them with the cams off the top of the motor. The guys at the front never charge me for them, just wave me through.

Good luck,

Mike

CaptJohn

Thanks Mike, great reply. I will try the allen wrench trick. I do not have any clearance but am able to spin the shim side to side so at least I have a guessing point where to start. All of the intakes were .008 and all of the exh except one were too tight to measure. I will also give the local bone yard a try, good suggestion. John

OutlawMike

John,

I have found the same thing. The exhaust valves run hotter and seem to move in faster than the intakes. Kind of makes sense.

Low compression could very well be due to a lack of good preload on the valve seat, due to no clearance at the cam lobe.

Have fun, PM me if you run into trouble.

Mike

GSGALLANT

I found the above tools very easy to work with, in my experience.

CaptJohn

Mike's trick worked just fine, I did order to tool from E-Bay for future use. Unfortunately I put a thinner shim in, had .08 clearance where I had none before, and behold.. No difference in compression, actually a little less....I did not want to pull these heads but I guess I have no choice now. This 3.0 is actually in a Toyo motorhome and I want it to be right and dependable so I think I'm going for it. Local shop quoted me 2-3K he was not sure. If I do it myself using the local machine shop it should be under 1K or so I hope... At least this is not my daily driver, have the time. Thanks for all the help, this forum is great....John

OutlawMike

John,

Sounds like you have to pull them. I paid a little over $900 to get my heads rebuilt with new exhaust valves and new guides. Included in that was an oversized seat for the #6 intake, as it had dropped out of the head, hence why I pulled them.

The shop will need to buy a seal kit to do the heads, you might want to have them buy the full engine seal kit, if you have leaks elsewhere to fix.

Oh, and new head bolts are a must, do not skimp on this item. The bolts are torque to yield. Re-using old bolts will run a high risk of blowing a head gasket. Follow the FSM instructions for tightening the new bolts.

The knock sensor is under the intake manifold. The jumper wire from the harness to the knock sensor cooks over time and is very, very brittle. At the very least, buy a new jumper wire for the harness from the dealer. They are not very much money and you do not want to be back in there to fix that damn jumper wire. What engineer puts the knock sensor under the intake? At least the starter is not there like some newer motors.

The torque spec for the knock sensor is 52 in-lbs, if you end up pulling it off from the block. I could not find that in the FSM and got that number from the master tech at my local Yota dealer.

Have fun,

Mike

CaptJohn

Thanks Mike, you have been a great help. I just traded in my wifes 01 Land Cruiser because it sucked on gas etc. I put a starter in that. Thought I was nuts looking under the intake, but there it was. Really miss that car, just got rid of it and have sellers remorse, but then again, lots of maintenence. Oh well, can't have it all. Sure I'll be back with some dumb ass questions...heads are coming off, after I do a wet cylinder test. If the compression test indicates worn rings, I'll rethink this whole motorhome full of worms. John