what is up with the 3vze's burning up the exhaust valve on #6? it seems that so many owners have had this problem. i have it right now but i cant spend 500 bucks or whatever to have it fixed. oh well....maybe i will try to do it myself. anyways, does anyone know why this happens so often?

 

I think its how the exhaust flows out

 

DUDE is correct....The cross over pipe from the 1-3-5 side joins to the 2-4-6 side and instead of using a downward angle toward the cat Toyota pointed right at the number 6 cyl. So that exh valve gets hit with all the exh heat from the 1-3-5 side of the eng.

There are many threads here that can help guide you through the process........

 

how'd you determine the problem? if I ever get my valves replaced I'll definitely consider headers to eliminate the stupid stock crossover.

 

this is informative...if you scroll down you can see pics
http://www.4wdmonthly.com.au/forum/i...d=6133;start=0

 

that is only part of the problem...

Exhaust #6 is the one that burns because, yes it is exposed to the most amount of heat. However the heat is NOT the direct cause of this. Lack of maintainance is. The heat merely makes that particular valve more prone to stretch and when it stretches valve lash decreases. When valve lash is at zero, the exhaust valve can no longer seat on the cooler head and dump the heat it has picked up. Wola! Burnt valve from lack of maintainance.

Remember, your valves are SUPPOSED to be reshimmed every 80,000 miles.

I was DAMN close to burning a valve in my 3vze at 255k miles for the #6 exhaust valve was down to 0.003" valve lash.... Now that lash is back up to 0.013"

 

*point to remember*

 

I called the dealership for a price to fix the burnt valve. 1500 to 1600 dollars. Called a local mechanic and he wants a thousand. how are there people on here who have had a full valve job for about 300 bucks? i dont get it. i just want the exhaust valve on #6 fixed.

 

Here's the truth: The Numero 6 valve will burn up on the 3.o because of mis-engineering! How you ask: Simple, the same problems that hurt the 3.0 for years, air and breathing, you see the 3.0 can't breathe well, that damn misengineered crossover is the cause of the #6 going t/u! No SH**! The lack of air or lack of causes a congestion in the entire engine, #6 is suffering because it is not getting enough air, result, b/u #6! Tsk! Tsk! Truth be told, replace the x-over get some headers and whalla! No more b/u #6! That is the truth and thats why #6 gets burnt up! Make sense? Probably not, what if your fuel sys. just wasn't getting enough air to stoke the fire? Same thing, no air not complete combustion carbon builds up and "POW!"

 

Nunsa,

In your time as a Toyota Tech, how many 3vze's as a percentage would you run accross that had a problem with the #6 exhaust valve burning out?
How common is it? Very common? Or Rare? Or somewhere in between?
Did you reach Master Toyota tech status? How many years were you a tech?
How many 3vze's would you work on in say a year?

 

nunsa is on the right track...but bumpin yota has gotta point too. bottom line is ya gotta baby the valves so none burn especially the #6 exhaust valve because of the crossover pipe that does seem to help the burning process along.

 

Wow that's a lot a questions! one at a time.
The percentage rate of #6 valve going in a year would probably be around maybe 15%! It really isn't that common, it usually goes with the HG and/or the x-over, yeah, the x-over causes your 3.0 not to breathe, it's a fact! air can't get back there to cool the bugger down, congestion!!
Yes, I achieved Master Toyota Tech , T-10/ and ASE Master. I was a Toy Tech for over 6 years.
I worked on a lot of 3.0's, let the truth be known, when the HG recalls came out I was doing 2 - 3 HG's a night, by the end of the year I could knock out 4 -5 as long as there were'nt any problems: i.e. - burnt valves, cracked heads...! Me and the 3.0 got to know each other real well, after awhile it gets to be like a production line! I'll always love the 3.0 maybe for thet reason because I got to know them so well! They're a piece of cake to work on!

 

Yeah - myself personally I'm on the fence on what I should do when my 3.0 gets a little more aged. I could either have it rebuilt with NWOR or Downey Headers matched with an exhaust system. Or swap in a 3.4. And I'd probably put headers on the 3.4 and have a custom crossover pipe built in to keep the exhaust coming out of the stock side. So it'd basically be a 3.0 with headers, or a 3.4 with headers. I'm guessing it'd be a few thousand more to deal with the details surrounding the swap though as opposed to just the rebuild with headers/exhaust.

 

it hasn't been around quite long enough yet, but i think the 3.4 is gonna prove to be one of the best engines ever made (kinda like the 22R series but with a whole lot more power)...i'd think hard about swapping in a 3.4 when the time comes if i were you.

it's the only engine i would ever consider replacing my 22RE with (other than another 22RE )

nunsa...i'm surprised you got rid of your old 3.0...what happened to it? looks like you got a sweet replacement truck, though.

 

On my old 3.0 I wasn't sure what to do, my old 3.0 with 285,000+ miles HG started to leak, I rebuilt her and did it right, Downey headers, 2 1/4" exh., High flow cat, oversize valves and injectors., Headers, Supra AFM, custom air intake, ported polished heads, yeah she ran like a dream, actually she screamed, I hated like hell to get rid of her, now i have a '03 Taco, fully loaded, 3.4 OffRoad/TRD package. No mods! She takes a liking to the mud!
I hope I get as many miles out of these as I did my (3) - 3.0's, we'll see!
Good Luck!
Harry

 

How would you compare the stock 5vzfe to your modded out 3vze in terms of power?

 

Hot Damn, you beat me to the punch, I was just going to ask that exact question!

 

I, too, am curious about the horse power comparision between the two engines, however, I'm concerned about the x-over/header issue.

So I humbly submit the following for your review, consideration, conjecture & input:

What if...? As in, what if the 3.0 is'nt a victim of "mis-engineering" (nunsa) due to considerations of "cost" (dragon564)? What if it was the victim of something altogether different...??

For instance, ever notice how EVERYTHING on the 3.0 is crammed on the passenger side of the engine compartment, with the exception of an OVERLY exaggerated intake system with it's multiple, displaced "silencers" all twisted & convoluted about all over the place for no readily apparent reason in an otherwise empty space ???

What if the 3.0 were originally engineered to be TURBOCHARGED ?!? Bear with me while I ponder...

In looking at the exhaust assembly, the crossover pipe in particular, I don't know about you guys & what all your experience is around cars, but I've been tinkering on them for awhile now (you know, bringing the dead back to life, making crap run & tuning land rockets...just the usual shade tree-tuner stuff) &, correct me if I'm wrong, but does'nt it look as though the exhaust manifold was fabricated for a "turbo" installation, judging by it's flange & outlet configuration?? Could'nt you just see a "snail" sitting there at the downpipe flange with an outlet/boost tube curling up & mating to the intake that's, conveniently, right there above it ? Not to mention an oil system assembly, also conveniently located in the same area for, say, taping a "feeder line" to ??

At least that's what I thought of when I first looked at it & that train of thought lead me to a dual exhaust configuration, which is what you would need if you had a "spooler" sitting there, & then cost started to figure into the equation (the unit itself, associated plumbing, waste gate, etc., etc.) & that seems to be what everyone is trying to stay away from, afterall, why sit there & go through one burnt valve after another, as well as other associated engine failures & mishaps, but for what it would cost you to find a no-hassle-install, aftermarket header?!

So I called into the station master & had him do some signal switching & rerouting for me & basically came up with an equation wherein I took the "compressor" out of the configuration (due to expense, but just tabled it for future consideration, afterall, imagine that!!), leaving me with a dual exhaust set up & wondering how to make it work, cheaply, that is.

So I went back to square 1, &/or the crossover/header configuration, & upon taking a closer look at the headers, now correct me if I'm wrong here, but if you take the passenger's side header, flip it upside down & hold it to the driver's side head, would'nt it's mounting flange mate up perfectly with no modification at all !?!?!

From which you could then have a local muffler shop fabricate a dual (or stick with the single outlet, but just have them "Y" the two pipes a considerable distance "away" from the block [& the #6 cylinder]) system, pehaps even using the stock mounting flanges cut off of the x-over to insure a clean fit to he stock headers (stock to stock),...thereby effectively eliminating the need for the x-over, poor exhaust "breathing", excessive engine heat, costly aftermarket headers & needlessly expensive valve jobs, not to mention boost overall engine performance & horsepower?!?!?!!!

Now there's something for everyone here to mull over that we would all benefit from (greatly!), so let me know what you come up with when I come back tomorrow (although it's already "tomorrow"), my head hurts & I need to go lie down.

 

interesting thought train, I like it!! The 3vze DID replace the 22rte, so it is very possible that they set up this engine to be capable of being turboed to keep up with the market's HP increases over time. It's only a 9.6:1 CR so its VERY boostable. And a properly tuned, turboed 3vze I bet could MORE than keep up with an early vortec 4.3...

As you mention, there IS an unused pressurized oil outlet on the front driver's side of our block, the Xover does dump straight in, there IS room for a 3" downpipe, there is room for an intercooler behind our OEM skid plate (which btw has air flow slots.)

Hmmm interesting thought train!

The one question I have however, where can we get multilayer steel HG's made? Or even copper for that matter?

 

I know a couple different people from tuning here & there that could come up with them. I'll get in touch with them & find out just who the supplier is, although I know a machinist or two that could probally punch them out from scratch, if that need be the case. Whhoooooooossssshhh!

Thanks for the positive input "Bumpin", but hey, don't get ahead of me , if you stand in front of a train you're going to get ran over. : Remember that I was "tabling" that particular train of thought for future consideration due to "expense", but you're right on track. (Amazing, is'nt it, what people don't see even if it's right there in front of them ?!)

What I'm focused on now is gathering input on the "inexpensive" stock header modification to eliminate the crossover & it's accompanying headaches & hardships to save everyone here & out there in 'yota land money on needlessly expensive "fixes" (valve & ring jobs) &/or "upgrades" (i.e., "headers") to solve something that, from my perspective, should'nt have been broken to start with.

So any input there would be appreciated , although I am sketching out plumbing routing plans, but that's for later.