My First Blown Head Gasket (I think)!

Congratulations to me! I think I may have encountered my first blown head gasket.

Thank you. Thank you. It was nothing really.

Well, I just finished putting my 3VZ-E back together last month after doing some overdue PM and clean-up. Even with 295K on it and no rebuilds, she ran great - in fact, as good as ever. Those Toyota guys really do some things well.

But, last week, the 4Runner ran rough for the first couple of seconds after start-up in the morning and, then, it would smooth out. It got a bit worse over the course of days (took as much as 30 sec. to smooth out the idle) until this morning I was never sure it really ever smoothed out completely. It still ran okay, but something didn't 'feel' right as I drove to work.

Same deal on the way home tonight - it didn't feel right. Then, it was dark and my neighbor was behind me on the way to my house and I noticed the dreaded smoke behind me in his headlights. I have never seen this before in the 14 yrs I have owned the vehicle and I am thinking it is not a good thing.

I get home and start going over some things. I check the oil and it looks beautiful. So, I am thinking induction. I checked out a few items (mass flow meter, throttle position switch, blah, blah, blah) and then made my way to the ingition. Coil is good. Distributor pick-up coil is a bit out of spec but it just doesn't seem to be enough to be the problem.

I am scratching my head and thinking compression test this weekend.

By now, the engine has cooled enough to pop the lid on the new radiator I have just put in and she's low on coolant. Also, the cap looks like it may have some oil on it. Not sure, though and I cannot swear I completely filled the system when I put it all back together. Perhaps some air was trapped in it (dream on baby.) So, I put a bit of coolant and distilled water in the radiator, enough to fill it up, and as I pull the funnel out, there is not doubt in my mind of what I see floating on top of the coolant. Oil.

So, blown head gasket . . . right? What would cause this? Can they just wear out? The truck has never overheated in its life. I am thinking it just wore out but, like I said, this is all new to me.

Oil in the coolant but no coolant in the oil (I think it may all be on my neighbors windshield). Does this sound about right?

If so, how do I fix it? Just pull the heads, replace the gaskets, and slap the heads back on with new bolts? Anything else I should take a gander at while I take this thing apart (again)?

Thanks for the help. I really need it on this one.

Luther

Reply to
Luther
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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.

completely.

Reply to
James Andrus

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?
Reply to
MDT Tech®

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:

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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

Reply to
Whitewall Junkie

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

Reply to
Luther

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.

Reply to
MDT Tech®

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.

Reply to
MDT Tech®

Reply to
MFINJA

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...

Reply to
miike

If it was a problem, you'd get a check engine light as soon as the engine goes into closed loop and engien rpm's go over 1800. Its on the engien block in the middle under the intake. he conector is right near injector connector #4.

Reply to
MDT Tech®

22R engines never used stretch bolts.
Reply to
MDT Tech®

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