Retightening Exhaust manifold bolts

Blk63vette · 11-08-2009, 07:46 PM

Hello

I replaced all exhaust manifold gaskets on my 94 Toyota 2wd truck with a 22RE engine four months ago before taking my job in Indiana. Alot of the threaded rods were every loose and are not very tight into the head. I put JB weld to anchor the thread rod into the head. The one on the end was chewed up and extremely loose stripped inside of head JB Weld trick didnt work like the rest and would not work. I can hear the engine getting loud when they are loose. I had to drill into the head to accomdate a large threaded rod. I used two bolts to lock it in tight. This worked for about four months. (All summer and about 3 thousand plus mileages) Until today, I noticed that it was getting louder again and the valve clatter when driving. I retightened all the nuts when the engine was hot and the troublesome one in back too (Extremely loose). Drove it around and let it cool down and again retightened up bolts when engine was cooler. Engine was much much quieter expect for some ticking up front. I was wondering if this is "Normal" to keep retorque the exhaust manifold bolts to the head?

They all seemed alil loose second time around.

I didnt kill it on there but I but it on better than snug (tight). I was told this is NORMAL for a a aluminum head to expand and contract over time (years) the threaded rods will eventually get loose inside the head.

So, I just keep tightening the exhaust manifold bolts every now and then?

Am I missing something here?

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Blk63vette · 11-08-2009, 07:55 PM

Bump Bump

bugs1961 · 11-08-2009, 08:34 PM

The nuts should be tightened to the FSM torque spec. I haven't had one come loose when properly tightened. The studs are not supposed to be overly tight in the heads--just firmed up. I've never heard of epoxying the studs to the heads and don't think that's a good idea. If you have a threaded hole in the head that's stripped, it really should be fixed with an insert such as Helicoil.

Myron · 11-08-2009, 08:40 PM

According to Alldata, they need to be torqued down to 33 ft.lb
Try that and see if they still come loose. I know that the bolts will expand when its hot, but should contract when it cools down along with the head.
I always use NEW bolts especially dealing with the Alum Head.
Let us know the outcome.

75k5toy · 11-09-2009, 04:43 PM

there's a bracket bolted to the bell housing with a wide clamp that holds the exhaust pipe. maybe yours is not atached and the weight and vibration causes the bolts to get loose. you should check that out, and for the exhaust studs I heard some guys turn them around cause the other side has longer thread. and can be bolted a li'l deeper. just my idea.

Myron · 11-09-2009, 05:08 PM

Becareful on that turn around, you dont want it too deep into the alum head.

yota4runna · 11-09-2009, 05:08 PM

It's very common for the lower right exhaust manifold stud [nearest to the firewall] to strip out. That stud screws into the EGR passage in the head, and has fewer threads, as well as being out at the end of the manifold.

The only good fix for it is to remove the manifold and heli-coil that hole. M10x1.25 threads.

Blk63vette · 11-09-2009, 05:08 PM

Hello

When I took the nuts out to replace the exhaust manifold gasket and all but one the studs came out of the head. I had to put the stud in the vise to get the nuts off!!!

So, most of the studs were "loose fitting" when I put them back in..So, I used the JB weld to keep the studs in place. Seems to be holding pretty good today..We shall see...

11-08-2009, 08:34 PM	#3 (permalink)
bugs1961 Registered User Join Date: Jul 2006 Location: Albuquerque Posts: 245	The nuts should be tightened to the FSM torque spec. I haven't had one come loose when properly tightened. The studs are not supposed to be overly tight in the heads--just firmed up. I've never heard of epoxying the studs to the heads and don't think that's a good idea. If you have a threaded hole in the head that's stripped, it really should be fixed with an insert such as Helicoil. __________________ '89 V6, 5 spd truck and '07 FJ Cruiser

11-08-2009, 08:40 PM	#4 (permalink)
Myron Registered User Join Date: Sep 2006 Location: Scottsdale,Arizona Posts: 191	According to Alldata, they need to be torqued down to 33 ft.lb Try that and see if they still come loose. I know that the bolts will expand when its hot, but should contract when it cools down along with the head. I always use NEW bolts especially dealing with the Alum Head. Let us know the outcome. __________________ 1987 Pick Up 2.4L 4x4 2004 Rallirt 2008 Taco

11-09-2009, 05:08 PM	#6 (permalink)
Myron Registered User Join Date: Sep 2006 Location: Scottsdale,Arizona Posts: 191	Becareful on that turn around, you dont want it too deep into the alum head. __________________ 1987 Pick Up 2.4L 4x4 2004 Rallirt 2008 Taco

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11-08-2009, 07:55 PM	#2 (permalink)
Blk63vette Registered User Join Date: Sep 2009 Location: Sarasota, Florida Posts: 49	Bump Bump

11-09-2009, 04:43 PM	#5 (permalink)
75k5toy Registered User Join Date: Apr 2006 Posts: 75	there's a bracket bolted to the bell housing with a wide clamp that holds the exhaust pipe. maybe yours is not atached and the weight and vibration causes the bolts to get loose. you should check that out, and for the exhaust studs I heard some guys turn them around cause the other side has longer thread. and can be bolted a li'l deeper. just my idea.

11-09-2009, 05:08 PM	#7 (permalink)
yota4runna Registered User Join Date: Oct 2007 Location: Southern Ore. Posts: 326	It's very common for the lower right exhaust manifold stud [nearest to the firewall] to strip out. That stud screws into the EGR passage in the head, and has fewer threads, as well as being out at the end of the manifold. The only good fix for it is to remove the manifold and heli-coil that hole. M10x1.25 threads.

11-09-2009, 05:08 PM	#8 (permalink)
Blk63vette Registered User Join Date: Sep 2009 Location: Sarasota, Florida Posts: 49	Hello When I took the nuts out to replace the exhaust manifold gasket and all but one the studs came out of the head. I had to put the stud in the vise to get the nuts off!!! So, most of the studs were "loose fitting" when I put them back in..So, I used the JB weld to keep the studs in place. Seems to be holding pretty good today..We shall see...