Firefyter-Emt

Well.. my 4-Runner is getting ready for the heads to be redone again.. Yes, again! I have been fighting this for 2 years come this Feb.. Yep, the first set was done in Feb 2002 at 120k.. I now have 150k and 2 years later it still runs like crap.. I have had 2 set of heads built and the last set has been back for adjustment 3 times.. Now let's all pick brains a bit.. I have a theory, can a valve "bend" or warp downward from having too much cut off when a valve grind is done?? Now I am not talking about a head that has been done too many times. But maybe the valve has so little stock, you can not safely grind them?? I just did a compression test and once again I have 30psi on #6 (155+ on all others) Now this is the same cylinder that the guy has been re-shimming... He will put a thinner shim in, and about 3k later it is too loose.. Now there is no adjustment on these valves that can change, it is all solid. I have basically had 2 sets of heads do this built by 2 companies.. I am going to ask him to install new valves (maybe just exhaust, that is the one that has been acting up..) BTW, this was a very dead cold compression test with about a 50% battery.. Anyone want to guess how sick of this I am??
:cry:

Mad Chemist

Lee,

How about swapping in a 3.4L and just ditch that engine altogether?

gwhayduke

Skip the 3.4. The intake is on the other side from your snorkel...Of course, you could be the first on your block...and maybe the world...to have dual snorks.

It might be cheaper and easier for your mechanic to go in with you on a factory 3.0 long-block.

waskillywabbit

iTrader: (-1)

I would have ditched that lemon back 2 times ago. Some things just aren't right and never will be no matter how many times you try to fix them. Sounds like you need to just take your loss and get a new one and sell that one to some "sucker" I mean nice person.

HaveBlue

The issue with your snorkel and a 3.4L swap can be solved with a 180° bent pipe from an exhaust shop. Not the most efficient thing in the world, but you won't have to pop holes in your fender again.

MTL_4runner

....or you could just sell the snork and fender to a 2nd gen owner, get a new fender, drill the other side for a new snork and a drop in a healthy 3.4L to make you one very happy camper.

1Runner

BING,BING,BING,BING........ Johnny, tell him what he's won!!!

(I think he's on to something here..)

Lee, sorry youre having so many problems w/ your rig.

Firefyter-Emt

Nope.. no engine swaps for me.. way too much cash$$ If all of you who just flip out with the "swap in a 3.4" has really changed a motor and swaped in a wrong year, diffrently set up motor you might just realize it is indeed expensive, and a great deal of work once you are done..

The "mechanic" BTW is me.. The problem seems to be rotating around the lack of strength in the valves after they have been re-ground. (and we are only talking about 1 valve grind here.) The shop who built the heads, has been great. They have re-adjusted the shims 3 times for free. Now this is a 6 hour (at least) job to get into the motor and fix it. Not bad service from a shop who did not even install the heads! I will be installing the new head once he gets it built. I am pretty sure that with new valves this time it is going to be good to go. I have only had this problem with one head so at least it is 1/2 perfect!

FattyCBR

The engine has to be completely warmed up in order to perform a useful and acurate compression test. If you didn't do that your numbers aren't worth a hill of beans. Also if your starter is slowing down I'd hook another running vehicle up to your battery and ground.

Also are the shim measurements being taken when the engine is fully warmed up? If not that may explain your shim problems.

Firefyter-Emt

I will agree about a warm compression test.. However, I have less compression at start up (as indicated by it running rougher untill it warms up..) I am sure I have better compression warm, that is not what I am looking for with this test. That being taken to mind, Yes the warm compression will be better if warm and a good battrey.. (which for the other 5 cylinders, makes me happy)

As for a warm engine for a valve check. First off, it is going to take you close to 3 hours of tear down to get to that point where you can even access the valves. Secondlay it is in direct opposition to the FSM which says " HINT: Check and adjust the valve clearance while the engine is cold" Please reffer to the FSM to see if you wish.. Yes some motors should be done warm.. But don't just assume that is the case with all motors. (Ya kanow what the word assume breaks down to, Right?? )

Just so that you all know.. I have worked on and been around cars / trucks all my life and am an ASE certified auto tech. I do know how to repair cars.. This valve problem is above and beyond the norm. It has managed to baffle the machine shop (who in fact builds race engines and is quite a wel known shop..)

Oh well.. One more head swap.. and I swear if this one ever craps out after replacing new valves.. The Runner is gone for sure!!

CTB

Hey Lee,

So sorry to hear about your misfortunres. Here's to wishing you luck with your head swap (it better be the last one, I don't want to see you get rid of your rig)...

Firefyter-Emt

Yea, you are not kidding.. 2 years, 20k !!! Can you say "not driveable most of the time"

(and that has 2 trip to PA and one to Tenn on it in that time!)

Mad Chemist

How's the jeep running?

Firefyter-Emt

That little pig is great! I have the back seat out and have been using it like a little baby pick up.. I can stuff 1/4 of a cord + of fire wood into the back of it. I dunno, something about the simplicity of it and the sound of the little 4 banger with 2 1/2" exhaust and a flowmaster that just makes it fun to drive.. It has been getting 100+ miles a day put on it. I had a little troubble with the clutch (turns out it was a cheaply made aftermarket clip that retains the hydro throw out bearing was failing and allowing the bearing to move of the retaining pin, which in turn would tweak the lines and make it leak.. I tapped a 1/4-20 hole and bolted it and all is good now

btw, here is a photo of the heep.. kinda old, but I think it is the only one I got.. LOL

Mad Chemist

Sounds like you're having better luck with the jeep than the 4runner! Sometimes I think people are a little too quick to jump on the unreliability of jeeps, particularly on this board.....

Gadget

Is the valve lash in proper adjustment?

If so have you had a cylinder leak down test done to tell you exactly where the problem is? If so did is show a ring, intake valve, or exhaust valve problem?

Verify the lash and then do the leak down test before you let anyone take anything else apart.

Gadget

www.GadgetOnline.com

Firefyter-Emt

Hey Gadget my friend.. Long time no "see" It is the exhaust valve most likely.. As I stated above, there is no "lash" to set, just those shims that need to be measured and changed. This head has had the exhaust valve re-shimmed 3 times.. At this point, he is going to build me a new head using one of the spare heads I have. I am having him install all new valves this time though. I did do a "wet test" for therings just for kicks and it made no changes, still 30psi. Yes, I could go thru the hassle of compressing that cylinder with my C02 tank and seeing which valve is leaking, but once you know it is a valve it has to come out.. #5 exhause has the mininum shim in it right now. I really feel good about this valve tulip condition, it would explain why the first set of heads also did the same thing.. If the valve is cut too much, they can not retain the proper shape and bend downwards while running (probably at higher RPM's) abd then they leak at low rpm.. This also explains why they are good for about 3k on the dot with an adjustment then start to leak again. every time it was re-adjusted it would be right back up to 150+psi..