re-torque head bolts?
05-14-2010, 02:04 AM
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re-torque head bolts?
Hello guys, just finishing up on 22r head gasket replacement. Have been seeing post that some re-torque head bolts after first start-up. doing it after she cools? is this ok? or nessasary? thanks,
05-14-2010, 05:10 AM
#3
I don't know the answer but I do recommend it!! A couple of months ago my truck shut off at an intersection, and when I tried starting it, it ran really rough and a lot of white smoke from the exhaust. It would shut off unless i gave it a lot of gas, but i managed to make it home.
I thought it was the headgasket, i changed it about two years ago but never retorqued it, so i got to work. I was hoping a simple retorque would fix the problem, but all bolts were torqued to spec. except for one. It was about a half turn loose. I buttoned it back up only to get the same problem, but in the end it wasn't the headgasket. It was just some bad gas and after a fresh refill it has been running great ever since.
I thought it was the headgasket, i changed it about two years ago but never retorqued it, so i got to work. I was hoping a simple retorque would fix the problem, but all bolts were torqued to spec. except for one. It was about a half turn loose. I buttoned it back up only to get the same problem, but in the end it wasn't the headgasket. It was just some bad gas and after a fresh refill it has been running great ever since.
05-14-2010, 06:05 AM
#4
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EB said to do it, I'd do it (on a 22re). Its not practical to do it on a V6.
Here's EB's special head bolt torquing proceedure.
I quote EB :
Here's EB's special head bolt torquing proceedure.
I quote EB :
>>>*Other than simple overheat, the #1 cause of head gasket failure is clamping force variations.
Usually when I mention this, the answer is "I torqued it properly!"
*Yes, very likely, but torque, which is a twisting force, means almost nothing when we are talking about clamping force.
Dirt or machinery debris in the bolt holes will throw the clamping force off as much as 50% and more, even though the torque wrench reads perfectly normal.
The same happens when installing new bolts. The very best bolts made will show a rough mating surface at the threads when inspected under a microscope.
When installing new or used fastners, first be sure the bolt will spin in and out ALL THE WAY freely with simple finger pressure. Be sure they are lightly oiled, not too much which can hydraulic lock at the bottom of any blind holes and spoil your day.
Use this simple breakin procedure for any new bolts: Tighten all of them to 50%, back off 1/4 turn, then to 75%, back off 1/4 turn. Then take them to 100%, back off 1/4 turn and repeat. Do a retorque after full warmup.
*This procedure simply assures that the imperfections of the threads seat to the bolt hole threads.
Yes, time consuming, but much faster and less costly than another set of gaskets, the actual clamping force will increase vastly, even though the torque load is exactly the same.
The alternative is you may be additional twisting at the top of the bolt after the threads have come to a stop from excess friction.
If any single one does that, head gasket failure prematurely is gauranteed, plus it weakens the bolt....*EB
Usually when I mention this, the answer is "I torqued it properly!"
*Yes, very likely, but torque, which is a twisting force, means almost nothing when we are talking about clamping force.
Dirt or machinery debris in the bolt holes will throw the clamping force off as much as 50% and more, even though the torque wrench reads perfectly normal.
The same happens when installing new bolts. The very best bolts made will show a rough mating surface at the threads when inspected under a microscope.
When installing new or used fastners, first be sure the bolt will spin in and out ALL THE WAY freely with simple finger pressure. Be sure they are lightly oiled, not too much which can hydraulic lock at the bottom of any blind holes and spoil your day.
Use this simple breakin procedure for any new bolts: Tighten all of them to 50%, back off 1/4 turn, then to 75%, back off 1/4 turn. Then take them to 100%, back off 1/4 turn and repeat. Do a retorque after full warmup.
*This procedure simply assures that the imperfections of the threads seat to the bolt hole threads.
Yes, time consuming, but much faster and less costly than another set of gaskets, the actual clamping force will increase vastly, even though the torque load is exactly the same.
The alternative is you may be additional twisting at the top of the bolt after the threads have come to a stop from excess friction.
If any single one does that, head gasket failure prematurely is gauranteed, plus it weakens the bolt....*EB
Last edited by mt_goat; 05-14-2010 at 06:12 AM.
05-15-2010, 02:20 AM
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Thanks for the posts, Guess im still on fence what to do.......i still have not done the ....1st start yet, still cleaning gulk milkshake out of oilpan and screen,,got a new radiator from local napa for 98$ saved me some shipping cost$ few wires and hoses and pray, turn key, pray some more. 1986 2wheel drive 22r (carb) rust bucket,(why im i dumping money in that piece of junk! says my wife)
02-09-2012, 09:47 PM
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I know this is an old one, but good advice in here. Wish I had read it before. Just did a head gasket, didn't know about the retorque after first startup. Was running great for 20 mins, then I noticed temp gauge not working right and stopped it. Coolant in the oil, barely. Hoping a retorque tomorrow solves it.
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02-10-2012, 02:56 AM
#8
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02-10-2012, 07:49 AM
#9
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i have a 3.0 i would assume it is smilier on the 22re...the bolts are one time use bolts you need to replace them after one use because when u torque them down how it say you actually stretch the bolt out and that keeps it from backing out and no need to retighten
02-10-2012, 08:20 AM
#10
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02-10-2012, 09:04 AM
#11
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22re's are not torque to yield bolts and can be reused, like mt goat said.
I am not on the whole retorquing of head bolts band wagon. I think it started because part suppliers (EB) found a lot of people calling in and saying their head gasket is leaking. So like any business would do, they say just retorque them down and see if that helps. I bet a lot of times it did work, and prevented them angry customers or warrenty work. Then it just became sort of a common practice to protect them, because what could it hurt?
I believe a lot of people out there have torque wrenches that are not very accurate. So there not getting an accurate torque on the bolts in the first place.
If a bolt looses tension, then some other force is acting upon it to loose tension, like dirt in the holes.
Here is the question though, why does an aftermarket parts supplier say retorque head bolts, but the FSM and Toyota does not? Makes you wonder dosen't it...
I am not on the whole retorquing of head bolts band wagon. I think it started because part suppliers (EB) found a lot of people calling in and saying their head gasket is leaking. So like any business would do, they say just retorque them down and see if that helps. I bet a lot of times it did work, and prevented them angry customers or warrenty work. Then it just became sort of a common practice to protect them, because what could it hurt?
I believe a lot of people out there have torque wrenches that are not very accurate. So there not getting an accurate torque on the bolts in the first place.
If a bolt looses tension, then some other force is acting upon it to loose tension, like dirt in the holes.
Here is the question though, why does an aftermarket parts supplier say retorque head bolts, but the FSM and Toyota does not? Makes you wonder dosen't it...
02-10-2012, 09:53 AM
#12
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I have a Fel-Pro in my truck now with about 5,000mi on it that I have retorqued twice now. The first time it needed it; the second time all the bolts were pretty consistent. My fingers are crossed that it will hold until I can find another decent engine for a decent price.
02-10-2012, 09:43 PM
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Re-torque at about 500 miles, the head bolts do stretch and the heads slightly warp (cast iron block, aluminum heads, steel bolts). Also re-adjust your valve clearance.
02-12-2012, 10:41 AM
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I retorqued mine at 100 miles. I forget where I heard this number, whether it was on here or the FSM. I also read/heard the head bolts "stretch" so retorquing them tightens them back down after the stretch. Everywhere I read DO NOT RE USE HEAD BOLTS. I did my HG almost a year and 5000+ miles ago and still going strong... If only my clutch/tranny were going good...
03-09-2012, 04:58 PM
#18
I'm in the middle of doing a HG job on a crate motor I bought 12 months ago. I put about 16,000 miles on it. Stinks that it only lasted this long before the gasket blew but I never did retorque (nor did they tell me too). I WILL BE doing a retorquw. SNOBDDS I understand your thoughts but I dont see where a retorque would hurt a thing, if nothing else it just verifies that they are staying tight. CHEAP INSURANCE!!!!! I would rather do a torque check every couple thousand miles than EVER DO A HEAD GASKET JOB AGAIN!!!!!!!!!!!
05-30-2015, 08:41 AM
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How do you re-torque TTY head bolts?
My 5VZ-FE procedure is torque to 35Nm, then turn 90*, then turn a further 90*.
So what do I do to re-torque after 100mi or 500mi?
Do I undo all TTY bolts, then torque to 35Nm, then turn 90*, then turn a further 90*?
Or do I look for evidence one of the bolts has loosened?
Thanks
My 5VZ-FE procedure is torque to 35Nm, then turn 90*, then turn a further 90*.
So what do I do to re-torque after 100mi or 500mi?
Do I undo all TTY bolts, then torque to 35Nm, then turn 90*, then turn a further 90*?
Or do I look for evidence one of the bolts has loosened?
Thanks
