22RE - exhaust manifold bolts backing out? (1 Viewer)

[digital]

I replaced the two exhaust flange gaskets and at the 'Y' pipe and the 1 big 'O' gasket in the front of the Cat. I believe I still have an exhaust leak at the exhaust manifold gasket. I noticed that the bolts are backing off slightly...

My question is, if I replace the exhaust manifold gasket with a new one, will it keep the bolts from backing out? I believe it is the original gasket, currently have 210k miles.

Thanks.

 

[WristPin]

if the manifold gasket isnt leaking, its not nessicary to replace it. and by doing so, its not going to affect the other nuts on other places on the exhaust. what you can do is use torque nuts. check out fastenal.com and find the right nuts.

 

[tntoyota]

I replaced the two exhaust flange gaskets and at the 'Y' pipe and the 1 big 'O' gasket in the front of the Cat. I believe I still have an exhaust leak at the exhaust manifold gasket. I noticed that the bolts are backing off slightly...


Thanks.

1st thing I'd do is locate the leak, sounds dumb but in my experience 22R/E's are notorious for breaking the welds to the flanges at the 'Y' mostly if its not bracketed to the bell housing.

It might be broke where you cannot see it, and I wouldn't want you chasing you tale replacing all the gaskets.

If you go out at night using a flashlight your eyes wont be flooded with everything you can see, instead you can focus only on whats in the beam.

My question is, if I replace the exhaust manifold gasket with a new one, will it keep the bolts from backing out? I believe it is the original gasket, currently have 210k miles.

So every bolt you've got is backing out?


Have you changed this gasket already?

 

[D'Animal]

Are the nuts backing off or are the studs backing out?

If the nuts are backing off, as wristpin mentioned, replace the nuts.

If the studs are backing out you can use exhaust temp rated Locktite. If you overtightend the studs you can easily pull the threads from the aluminum head.

 

[digital]

Only a few nuts backed off about half a turn or so, mostly to the rear of the manifold.

I haven't replaced the exhaust manifold gasket yet...The Y pipe is bracketed to the bell housing...I'll check that for leaks...Looks like I need to do a round two of the seam foam thing...

Thanks for the replies.

 

[KLF]

Are you sure that the threaded holes in the head aren't stripped? This is very common, I've had it happen to me twice. And of course, it's always the back ones that are the hardest to reach. What might be happening is the heat/cool cycles of the manifold is jacking the studs out of the head.

When I had the head off my engine, I went ahead and Timesert'ed all the threaded holes for these studs, so they couldn't strip when I torqued the nuts down.

 

[digital]

Are you sure that the threaded holes in the head aren't stripped? This is very common, I've had it happen to me twice. And of course, it's always the back ones that are the hardest to reach. What might be happening is the heat/cool cycles of the manifold is jacking the studs out of the head.

When I had the head off my engine, I went ahead and Timesert'ed all the threaded holes for these studs, so they couldn't strip when I torqued the nuts down.

I'll double check on the studs, what is "Timesert'ing"?

 

[2ndGenToyotaFan]

A timesert is a metal sleeve that you insert intot he head by drilling out a larger hole and tapping it to fit the sleeve, then screw the stud into that. Much stronger than the aluminum alone....

 

[axed existence]

after a timesert application, wouldnt overtightening simply turn the timesert, thus stripping the newer larger hole in the aluminum? im curious as this is new for me as well.

 

[2ndGenToyotaFan]

With the larger outer diameter, you have a lot more surface area to grab the aluminum... Also I think you use some kind of locktight, so once it's set it isn't gonna move. The manifold nuts are only supposed to be around 30 ft lbs anyway...

 

[KLF]

Jerod pretty much has it right. Timeserts are a solid insert, and you rely on the larger surface area of the new threads to gain strength. They're easy to install, but you usually have to buy a special drill bit and tap, so it can get pricey. I had to get them from Fastenal.

++ TIME-SERT Threaded inserts for stripped threads, threaded inserts, thread repair , stripped sparkplug's, Ford sparkplug blowouts, threaded inserts threaded, repair stripped threads, stripped threads, inserts threaded inserts, Ford spark plug repai

Helicoils are not a solid insert, they are a helical coil. So, as you apply torque from the fastener inside it, the coil expands a little bit and "bites" into the softer aluminum. There's a special insertion tool that you use to put them in, it grabs a little tang inside the coil and actually cause the coil to compress a little bit to make it easy to thread them in, then you snap the tang off and the coil "springs out" into the new threads. One of my spark plug holes and all my cam bearing cap threaded holes have Helicoils in them. Helicoil kits are easier to find, just about every autoparts store sells them and the kits.

Heli-Coil ( HeliCoil Inserts ) Helicoils Screw Thread Inserts | Emhart.com

I have read that Timeserts are better than Helicoils, but honestly in the applications we're talking about here I doubt you'll be able to tell or need the difference.

 

[GAS-A-LOT!]

holy thread revival BATMAN!
I'm in the same situation... I've got 4 OEM studs that I could return if I could find the strong enough, and longer 60mm hardware mentioned below. I've got the gasket on order (OEM unavailable) and would like to replace all studs so that I WILL NOT HAVE TO MESS WITH IT ANYTIME SOON. I cant take off the head because its my DD.

I got this from another thread.

"M10 x 1.25 is the bolt type you are looking for. Get one that is 60mm long (stock studs are 50mm)."

"The stock exhaust stud on a 22RE is a M10x1.25 x 50mm of which 20mm goes into the head. the head is taped to a depth of 40mm (as measured by calipers). By running a tap thru the hole and chasing the beginning threads, and using a longer stud (recomended)/bolt you are achieving the same 20mm of holding threads."

And then there is this option..

"Rocker stud for a SBC 7/16x14, the shoulderless stud
no need to drill. Just tap that hole out and install the stud! Cheaper and better fix than a heli-coil that can come out."

"That is a chevy SB shoulderless rocker stud, 7/16x14 tpi
I just send the tap through the hole without drilling and lock her down

Cheaper and easier than Heli-coil and can be done on the trail.
Found at NAPA"

And the final questions, If the manifold is warped, do i get it resurfaced? If so, where? Since its already warped, would it prevent further warping or just get worse. If worse, would it be best to buy a new one or be better off just getting some LC Engineering (smog legal) Headers? I'm limited in founds and would like the route with more value.


Sorry for the looooong winded post but I want to make sure I do it right.

 

[KLF]

I have my head off and completely stripped now, so just for the heck of it I went and checked. The stud holes are NO WAY 40mm deep, that guy is wrong. The deepest ones are only ~30mm, the 2 center ones, the others are all 25mm or a little less. If you drill them 40mm deep you will penetrate into the coolant passages, which will ruin the head.

You might be able to get the longer studs and have that work. Personally, if it were me I would do what I have done several times now: get a right angle drill and a Helicoil kit, fix it the right way. I did it on my son's '87 4Runner last Spring, we didn't even have to take the manifold off.

I don't remember what the allowable warp tolerance is on the exhaust manifold, but it's pretty high, look it up in the FSM. You can check it with a decent straightedge and a feeler gauge. The OEM gasket is pretty thick and will absorb a lot of warpage. Not sure what you mean about the OEM gasket being unavailable, but I have purchased many of them, I'm sure Toyota still has them. Maybe you mean "not in stock"?

 

[GAS-A-LOT!]

Cool, how do/will I know what kit to buy? As far as the manifold goes, if it needs recurfacing, where?

 

[KLF]

I would think any decent machine shop in your area could mill the manifold back to flat. But it might be cheaper to just get another one off of eBay.