Retorquing head bolts on 3.0?
#1
Retorquing head bolts on 3.0?
Hi all, thanks for all your help here I was able to replace the head gaskets on my 94 Runner 3.0 auto last fall. It was a PITA but everything seemed to go smoothly after I finally got the bugger torn down.
Since then the engine has run maybe 15-20 hours, but now I'm noticing some white smoke on startup, lasts until the engine warms up and then mostly goes away. It's really cold here and it may just be some condensation but I was thinking I would re-torque the heads just to be on safe side. I see a lot of posts on re-torquing the heads on the 22RE but none on the 3.0, and with the torque sequence and the two follow up 90 degree turns on the head bolts, I wasn't sure quite how to make sure they are re-torqued correctly.
I did make sure all surfaces were clean, flat, the head gaskets are not upside down, the head bolts were oiled up before torquing, etc. I just want to make sure everything's seated in fine. Any help?
Since then the engine has run maybe 15-20 hours, but now I'm noticing some white smoke on startup, lasts until the engine warms up and then mostly goes away. It's really cold here and it may just be some condensation but I was thinking I would re-torque the heads just to be on safe side. I see a lot of posts on re-torquing the heads on the 22RE but none on the 3.0, and with the torque sequence and the two follow up 90 degree turns on the head bolts, I wasn't sure quite how to make sure they are re-torqued correctly.
I did make sure all surfaces were clean, flat, the head gaskets are not upside down, the head bolts were oiled up before torquing, etc. I just want to make sure everything's seated in fine. Any help?
#2
YotaTech Milestone-Two Millionth Post
if I'm not mistaken, the bolts on the 3.0 are Torque to Yield (TTY)...and if I'm not mistaken, because of that, they are a 1-time use part.
so what I'm saying is I don't know that you can do that.
so what I'm saying is I don't know that you can do that.
#3
Registered User
Oh, don't start the TTY or not TTY discussion again. There is a TSB from Toyota on here somewhere that says they are re-usable after inspection and if they do not fail when you torque them. I was surprised by the TSB, not sure what to make of that, but it is what it is. I would not use them twice, and I will leave it at that.
Anyway, as for doing a retorque, I don't think you can do that unless you back them all off and then tighten them again, which I do not advise doing. Since there is no final torque number in the tightening sequence, what would you torque them too? As you know from doing the head gaskets, they are torqued by doing an initial, low torque of each bolt to seat them, then you rotate them by 90 degrees, twice. All in a set pattern. There is no torque to go back torque them too.
Are you losing coolant? And evidence of coolant in your oil?
Probably just condensation.
Mike
Anyway, as for doing a retorque, I don't think you can do that unless you back them all off and then tighten them again, which I do not advise doing. Since there is no final torque number in the tightening sequence, what would you torque them too? As you know from doing the head gaskets, they are torqued by doing an initial, low torque of each bolt to seat them, then you rotate them by 90 degrees, twice. All in a set pattern. There is no torque to go back torque them too.
Are you losing coolant? And evidence of coolant in your oil?
Probably just condensation.
Mike
#4
Registered User
They are TTY bolts and there are ways to check the specs per bolt to make sure they are in fact reusable. The initial 90* turn at the end of your tq spec is what makes the bolts stretch so I'm not sure I would go past that. Then again with all the 86-92 Toyota Supra's that I have done head gasket jobs on the initial 32 ft lbs was obviously a fail from the factory and I have used TTY up to 90 ft lbs with out fail. The problem is the heads usually strip and round sometimes and then your screwed.
#5
Well it doesn't seem to be using AF, at least not much (unnoticeable level change) if it is. I was more concerned about the steam (white smoke) at the exhaust but it could be a variety of factors (like condensation). It doesn't smell sweet and I think I'll just keep a close eye on it as the weather warms up and see what we have. Thanks again everyone, this board is extremely helpful!
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