retorquing head bolts?

Does anyone know if the 2TR-FE needs to have the heads retorqued after 1k miles? I ask because some old school mechanics suggest doing this on engines with cast iron blocks and aluminium heads as the two metals expand differently and stretch the bolt.

Not sure if it's maybe an old myth, something that has been addressed by manufacturers or whatever other reason.

 

Nope. I don't think anyone here has ever done this, especially since head bolts are stretched when torqued down and are non-reusable because of that. Tightening them again could snap them. If you're getting head lift from lots of boost out of a turbo and popping gaskets, then you'd be swapping to head studs before toying with potentially extracting a twice-tightened busted head bolt out of the block.

The 2TR isn't the odd one out for an iron block + alum head for Toyota. All 1st gen Tacomas (all three engines), all 4.7L Tundras, all Camrys before the 3.5L came out, so on and so forth used an iron block. But what's a recent Toyota engine that had a decent chance to blow a head gasket? The early all-aluminum 4.0L in the 2nd gen Taco until they revised the design of the gasket. How's that for irony.

Long story short, don't worry about it. Best thing to do to ensure longevity is not to go heavy throttle or high rpm on the engine before the thing has warmed up. That would be a great way to make the aluminum head expand way quicker than the iron block or steel gasket, not to mention how poorly oil flows to the bearings when thick and cold. Enough times doing that, and *pop*.

 

Well, the torque chart shows 29 ft lbs and that seems really low for head bolts. I'm used to 75-80 like on the 22R. Truck is at 138k and while changing out valve cover gasket I will be retorquing those bolts to 30 if they aren't still on it.

 

MYTH

jeeze

if that was the case it would be in huge red letters in the owners manual

 

Never heard of "re-torquing head bolts" on ANY engine' especially at 1K. If you have to tighten head bolts, you have other problems or it need to be switched to better bolts/studs. That or they are using a seriously piece of shit torque wrench that is inaccurate . I would take anything to these so called "mechanics" that you have heard of this from.

 

Will be interesting to see whether he comes back with a popped head gasket in a few weeks. If any of those bolts are looser I'd bet it's from the bottom head surface not being perfectly flat anymore. Sounds like a great idea to deform the gasket with that. One of those cases where you can directly cause the problem you're trying to prevent.

 

Well, the factory didn't do this and I've never heard of anyone taking a new truck back to have it done. I built a 22R-E about 10 years ago and the only things I can say are (1) follow the FSM procedure exactly (no thread lock, no anti-seize, do it exactly like the book says) with the right parts and (b) relax, don't worry, just drive it. I don't have a lot of experience building engines but I remember feeling the bolts take their torque and set. Their material properties and shape are not random, they distort when you torque them.

The initial torque is 29 ft-lb. The second pass is to turn the bolt 90 degrees and the third pass is to get the bolts to 180 degrees from their starting position after the first pass to 29 ft-lb. The process is different on a 22R-E and, FWIW, the spec is 58 ft-lb. The head bolts on a 22R are different in that they are actually technically reusable since they don't permanently stretch.

 

I think (hope) you meant 'wouldn't' ! 'Cause I sure wouldn't!

You can't find a much more old skool mechanic than dear ole Dad. He laughed out loud. From his crypt.

 

Thanks for that info. Wonder why what I was looking at didn't say final spec? Definitely feel better about 58 than 29. I'm only checking mine to make sure they are still where they should be after 138k since I'll be right there while doing vc gasket. Just tightened up all my 3rd member nuts since I noticed a seep starting the other day and they couldn't have been tight as they should be so that is why I figured I might as well check the head bolts. Stopped the seep on the 3rd member it appears. Dry after a few days of frwy driving back and forth to work.