Toyota Trucks: My First Blown Head Gasket (I think)!

When I blew my first and only (Nissan Z22), the first thing I noticed was
white smoke out my exhaust. When I got home the water was high in the
overflow tank ('cause of all the steam in the engine). I let it get cold,
which sucked all the water into the engine and left the overflow tank empty
and the radiator half full. So I filled it up and drove it around. Same
thing. The next morning I noticed an "grunt" before the engine would crank
(hydrolock -- water in the cylinder). Still in denial, I went to the
grocery store. When it got cold again, I filled it up again. Then I took
out all the spark plugs and cranked it. Water came squirting out the #1
plug hole. THAT'S PRETTY DEFINITIVE! Luckily it was only the gasket,
'cause I was almost broke at the time.

Failure is usually by corrosion of the metal sealing ring incorporated into
the gasket (one for each cylinder) (and to a lesser extent the head/block
surfaces surface it interfaces with). It is unlikely that this will ever
stop, there are difficult issues: dissimilar metals, acids created in the
oil and coolant. Add to this the thermal cycling of the engine which causes
cyclic compression of the sealing rings, and creep of the rings themselves
(creep is very slow deformation that metals undergo at elevated
temperatures) and it is quite an accomplishment to get them to last 295k.

Be lucky it probably is the gasket. Twenty to thirty years ago the aluminum
heads had a far greater tendency to CRACK. Around 1980 BMW had a major
operation going swapping out and repairing cracked aluminum heads. A
mechanic friend of mine got to be quite fast at swapping those heads.


"Luther" <net> wrote in message
news:supernews.com... 
doing 
ran 
after 
worse 
completely. 
dark 
in 
way 
may 
coolant. 
slap 

Luther wrote:
 


3.0 liter V6? Everything you mention points ot blown headgakset. Most
likely #6 cylinder, and second most likely is #1. If it had no trauma,
just replace the headgaskets. It should be fine. What year?

Although a couple big time Toyota freaks out here would say to not deal with
them for engines, go to DOA Racing and get the new head studs set they have
out. I've been wondering about doing studs on 3.0s to cure their constant
headgasket problems and apparently DOA thinks these are the ticket:

http://www.doaracingengines.com/index.html

I've been doing a ton of surfing on the net info gathering on 90's 4Runners
since 2 doors on my old 85 EFI 4Runner and a baby doesn't work well at all and
with headgaskets being such a huge issue on the 3.0s I came across a lot of
info on them. One thing peeked out a few times and never got enough attention
was the poor clamping of the factory headbolts. I'm guessing that going to
studs would stop the 3.0s headgasket problems. Just make sure and get the right
torque specs. Studs will get cranked down a lot tighter.
Heck, give Toyota a shot at it too. Maybe you can still get it covered under
the service campaign and not have to pay for the headgasket work at all. If
they do cover it, tell them you want to pitch in the extra $$ to use studs
instead of bolts so it doesn't happen again ;>)

Chris

 

1988, 3.0L. Am I eligible for the secret warranty replacement (or whatever
they call it)? Actually, all I would want would be a set of gaskets. I
would rather do the labor myself and know it is done correctly.

I will let you know what cylinder it was when I do the work. Could it be
#5? That plug was absolutely fused into the block during a recent engine
tune-up. It, literally, took me several laborious hours to get that thing
out and I wondered what in the heck could cause such a thing (Also, some
yahoo rolled the a new valve cover gasket on that side and oil leaked down
the block above that plug for a couple of years; so that could have been the
problem). So, MDT Tech has 50 bucks on #1. Any others?

$64 question: Do I replace the head bolts? Manual says reuse the factory
ones (but replace any that break trying to torque them - duh). Others
(including some on this list) say, "No way, they are TTY." The Toyota shop
re-uses them (not sure what that tells me.) Another Toyota technician has
told me it's okay to re-use them. It should be interesting to hear the
input on this. Finally, what is up with this 32 ft-lb, 90°, 90° routine for
torquing the bolts that the shop manual recommends? Is that (still) the way
they should be done?

Also, I just replaced the intake gaskets four weeks ago. Please tell me
that I don't have to replace those again.

Luther

Luther wrote: 

No warranty what so ever on these. These headgaskets were asbestos and
never had a failure problem beyond normal. (headgasket failure is normal
with time) There was a SPA (service policy adjustment) for these but all
of those have expired years ago. 


No, I want $50 on #6, then put me down for $20 on cylinder #1. ;D
 

Reuse them, and no one in our shop have ever had a single one break,
EVER! You can reuse them about 3 times, then all the stretch is gone.
Yes, the tourque you mention is correct. On that year, you will need a
1/2 drive, 12 point 14mm socket, thin wall (any good quality chrome one
will work, but it MUST BE GOOD QUALITY! 

OK, I wont tell you (but you will) and one other item to consider,
always replace the knock sensor pigtail wire that goes under the intake
and if you dotn replace the sensor, make sure the pin in the sensor is
bright shiny and clean. And corrosion in this sensor will disallow
ignition timing, and you will have little power and you will have to
remove the intake again to fix it. Oh, look real close to those
headgaskets, there is a LH and a RH side. DONT get aftermarkets either.
I've seen some "copies", (reverse engineered) the trouble with those is
they copied the 91-94 gaskets, the worst of the bunch! Wont get 50K at
best.

Whitewall Junkie wrote:
 


Unless you have a race car, dont even think about doing this. In most
cases, it require engine removal to remove the heads with these studs.
Its perfect if you are racing and have zuess faseners to strip off the
front end and no firewall in the way. The heads will hit the firewall,
wont come off the studs. Same goes for the 22R too.

>>In most cases, it require engine removal to remove the heads with these
studs<<

You can double nut the studs and pull them out just like bolts and not have any
clearance problems for head removal. I know for a fact it works on the 22re and
assume the same would hold true for the 3.0. And, in theory anyway, the studs
are infinitely reuseable without having to worry about any stretching.
My main concern about using studs would be on a metallurgical level. I assume
that the problem with bolts is largely the dual metals problem; the cast block
moving at one rate while the aluminum head is moving at another. With studs and
some mighty clamping force that is basically stopped, but I wonder about the
effects on the aluminum head. Could this forcible disallowing of movement
result in (to use words I don't really know) microcrystalline fractures that
could lead to real cracks and failures later on?

Chris

 

I'm about to go back in to do my 2nd t-belt+w/pump. i've been under the
intake plenum twice recently to replace leaky valve cover gaskets...where is
this sensor located (89 3vz-e)??? and, what's it cost? i noticed a lack of
power recently- thought it was just the 300+k miles...
--
regards,
-miike

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