shoes138

Ok to my understanding, On the 3vz-e motor why the headgasket blew was because of the material they used for the headgaskets. right? And it would usually happen in the # 6 cyclinder because of the exhaust manifold design it would dump all the exhaust vapors right into the number 6 cyclinder. now with that being said, the way to cure that problem is get the new n improved headgasket, headers, cams, O/S valves, Teds Headbolts. Correct? Now yesterday i talk to a guy here locally in sacramento that specialized in toyota engines, now he stated that cams, O/S valves would put more stress on the motor and even with headers and teds headbolts. The Motor would still blow a headgasket! and this is the reason, that each cyclinder has 4 headbolts, which makes it a very weak design. now would this be true? i thought mostly all motors come with 4 headbolts to one cyclinder?

TNRabbit

the 3vze only has 8 headbolts per side, which doesn't work out to 4 per cylinder...

I think the REAL reason has to do with dissimilar metals (aluminum/steel) and their differing heat/expansion properties. That's why an overheated aluminum head almost always blows a head gasket. BUT, that's not the only reason HGs blow (but most common one).

Jay351

I thought it was also caused by the crossover exhaust adding heat to the number 6 cyl area. Along with all the other reasons..

JackKnife

You are correct. The problem with the headgaskets was the material they were made out of. If a decent gasket and new head bolts or studs are used, the replacement will last a very long time. The reason that the 3VZ-E has gotten such a bad rap is that too many stupid mechanics don't understand how important it is to replace torque-to-yield bolts. They figure that since they haven't needed to replace bolts on other engines they've worked on and everything has worked out fine, that they don't need to do it on the 3VZ-E. Surely, one would think that the way one torques the head down with the two extra 1/4 turns that maybe something is a little different with this particular engine.

ewong

As far as I can recall - around this time there was also some kind of US Govt regulation on materials that caused a head gasket material change (lead maybe?) In any case - the first attempt at a new material wasnt the most successful..

TNRabbit

Old ones were made from asbestos.

mudbutt

Please check yourself before you wreck yourself!!

Per the FSM and TSB EG002-98 the Head bolts only should be replaced if they do not torque to specified range. So if your turing the extra 90degrees and it gets looser then you replace it.

There was a change in the manufacturing of the head gaskets. Asbestos was no longer allowed(along with brakes) to be installed in new vehicles. The new materials didn't get time to be propery enginered.

shoes138

ok well i guess the dood was wrong about how many headbolts but would a lot of headbolts make a big or lil difference for headgasket failing

TNRabbit

Well, more bolts, if properly placed, would give a more even distribution of pressure, so that would theoretically work. However, that all depends on the engineering of the head, bolt properties, physics, etc.

Also, in response to Mudbutt, Ted @ engnbldr.com began experiencing issues with re-used headbolts popping the heads off after torquing, so he began recommending the re-useable bolts he currently sells (you have to factor in a little bit of marketing into that decision as well!!).

weakyota91

TN explained it the closest to as the way i understand and was explaind to by the mechanic who did my last hg. toyotas have aluminum heads and a cast iron block. When u heat motor up (especially overheat) the castiron expands and aluminun dosent witch just crushes the gasket from the exapansion. so basically thats toyotas poor design. Im not sure why 3.0 are so notorius and not the 4 cyl. My mechanic said its very very common to expect to do a head gasket job every 80,000 miles on the 3vz-e motors

mt_goat

I ran across this the other day and found it interesting.

http://www.aa1car.com/library/2005/ic010532.htm

TNRabbit

That is an OUTSTANDING write-up. It should be permanently posted here.

mt_goat

Yeah I thought it was good.

iscool007

For those of you who don't know, Toyota send out a recall on the 3VZE head gasket blowout. I had a blowout two Decembers ago. I talked to my auto class teacher to look at the recall list and found Toyota put out a recall for blow head gaskets, so I took it to Bingham Toyota in Fresno, CA. (A certified Toyota dealer /repair station) I told them I knew about the recall and they looked up the VIN on my truck to see if it had been done on my truck. When it hadn't been done yet they said they do it for free.
They resurfaced the head gaskets and replaced the block for free.

91muddog

exactly, ive worked on toyotas before, i dont think i have ever actualy replaced the head bolts upon reinstalling the head. never had a problem either.

Yota82

A lot of different opinions on this issue: aluminum head/cast iron block, electralisys, crossover pipe, HG materal. The most logical explination is the crossover pipe since they always blow on #6. The crossover pipe was a dumb idea. As far as I know, Toyota doesn't honor the HG recall any longer. You have to hand it to them, they stepped up to the plate and lost millions of dollars on that deal. I think the whole aluminum head and cast iron block explination (while theroticly valid), lacks in explaination. Most of engines during that time and even to this day have aluminum heads with cast iron blocks who have not had such a problem. It definantly doesn't explain why 99% of the time it is the #6 cyl where the failure is. I would get headers for confort reasons. Not sure what oversized valves have to do with blown HG preventing though.

Jay351

Thanks but most of us already know The biggest problem is the re-placement gaskets blowing.

TNRabbit

I actually had one blow on the @#2 cylinder. I think I'm the only person in history to do so! :-)

Jay351

Maybe it was all that overheating?

shoes138

bump bump