Pete ot AL: Question for you; leaking header stud - ZR-1 Net Registry Forums

LGAFF · 04-27-2008

I have an oil leak frm of the header stud toward the back of the block. I went to remove the stud and starting turning the 15m bolt, and guess what, the bolt and stud are not welded. Needless to say any ideas? Not much room in there, getting some decent drips from it also.

LGAFF
92 ZR1
#234

lbszr · 04-27-2008

Quote:

Originally Posted by LGAFF

I have an oil leak frm of the header stud toward the back of the block. I went to remove the stud and starting turning the 15m bolt, and guess what, the bolt and stud are not welded. Needless to say any ideas? Not much room in there, getting some decent drips from it also.

LGAFF
92 ZR1
#234

Only aware of the stud that is in the middle installed with loctite 620. My engine was out then so don't know about accessibility. Easy with engine out though

Ccmano · 04-27-2008

You mean this issue?

20. TITLE - Oil leak from header studs.

YEAR(S) - All

PROBLEM - It has been well documented that the LT5 commonly leaks oil out of the header studs side, and leaks down on the cat. If it sits around a couple of weeks, it would smoke badly after about 5 minutes of warm up. On each header side is a stud located in the middle of the header, where it mates to the manifold. The stud is about a 1 1/4" long and has a nut welded on. The stud screws into the block and into one of the oil galleries. With all of the heat generated here, the stud will fail to seal and an oil leak is the result.

CORRECTION - To fix the problem, use the following procedure.

1. Remove the front tire from the side to be fixed.

2. Remove the rear inner wheel well. It has an assortment of Torx and hex head bolts.

3. You will now be able to look at the headers and see the stud, situated between the first 2 and last 2 cylinders.

4. Use a 15mm socket to remove the stud. The nut is welded on to the stud.

5. Clean up the stud, and apply a liberal amount of high temp Red RTV to the threads.

6. Very carefully thread the stud back into the manifold. This is the hardest part, as it is very close quarters. Don't drop the stud, or it will fall into the deep crevices of the exhaust tubes.

7. Let the RTV set up overnight, and enjoy a leak free LT5."

Hans

LGAFF · 04-27-2008

I used a crows foot to turn it, however does no good as its not welded to the stud. Appears whoever installed the headers just used anti-seize to seal them.

PS: I Need to learn how to

type!

LGAFF
92 ZR1
#234

lbszr · 04-27-2008

Mine weren't welded either, on either side.

04-27-2008

The nut is supposed to be crushed so it deforms around the stud. You can double nut it to remove it.

LGAFF · 04-27-2008

So I should crush my nuts?

Seriouly, I wonder if the wrong nut is on the car.

LGAFF
92 ZR1
#234

Pete · 04-27-2008

Lee if the stud comes out with the nut (most likely locking nut),so be it.
There is a bit of shoulder in the center of the stud small vise crip in the center of stud or a jam nut the other side take off the nut from stud.
15mm is factory OE size

Clean threads silicone,screw stud back in head followed by the nut.

Pete

kenthompson · 04-27-2008

Quote:

Originally Posted by LGAFF

So I should crush my nuts?

Sounds like a serious personnal problem to me.

LGAFF · 04-27-2008

Pete,

I've got $5 that says you can't do that in that amount of space. If you'd like to take me up on my challenge, I'm over in Crystal Lake. Then I'd be willing to bet another $5 you can't retime my cams.

LGAFF
92 ZR1
#234

PS: What the Hell is kind of smilie is this

....bad touch, bad touch...this should be banned!

04-27-2008	#1
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Pete ot AL: Question for you; leaking header stud I have an oil leak frm of the header stud toward the back of the block. I went to remove the stud and starting turning the 15m bolt, and guess what, the bolt and stud are not welded. Needless to say any ideas? Not much room in there, getting some decent drips from it also. LGAFF 92 ZR1 #234

04-27-2008	#3
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,843	Re: Pete ot AL: Question for you; leaking header stud You mean this issue? 20. TITLE - Oil leak from header studs. YEAR(S) - All PROBLEM - It has been well documented that the LT5 commonly leaks oil out of the header studs side, and leaks down on the cat. If it sits around a couple of weeks, it would smoke badly after about 5 minutes of warm up. On each header side is a stud located in the middle of the header, where it mates to the manifold. The stud is about a 1 1/4" long and has a nut welded on. The stud screws into the block and into one of the oil galleries. With all of the heat generated here, the stud will fail to seal and an oil leak is the result. CORRECTION - To fix the problem, use the following procedure. 1. Remove the front tire from the side to be fixed. 2. Remove the rear inner wheel well. It has an assortment of Torx and hex head bolts. 3. You will now be able to look at the headers and see the stud, situated between the first 2 and last 2 cylinders. 4. Use a 15mm socket to remove the stud. The nut is welded on to the stud. 5. Clean up the stud, and apply a liberal amount of high temp Red RTV to the threads. 6. Very carefully thread the stud back into the manifold. This is the hardest part, as it is very close quarters. Don't drop the stud, or it will fall into the deep crevices of the exhaust tubes. 7. Let the RTV set up overnight, and enjoy a leak free LT5." Hans

04-27-2008	#4
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Pete ot AL: Question for you; leaking header stud I used a crows foot to turn it, however does no good as its not welded to the stud. Appears whoever installed the headers just used anti-seize to seal them. PS: I Need to learn how to type! LGAFF 92 ZR1 #234

04-27-2008	#5
lbszr Join Date: Nov 2006 Location: dayton,ohio Posts: 424	Re: Pete ot AL: Question for you; leaking header stud Mine weren't welded either, on either side.

04-27-2008	#6
Jeffvette Guest Posts: n/a	Re: Pete ot AL: Question for you; leaking header stud The nut is supposed to be crushed so it deforms around the stud. You can double nut it to remove it.

04-27-2008	#8
Pete Join Date: Dec 2003 Location: Chicagoland,IL Posts: 2,667	Re: Pete ot AL: Question for you; leaking header stud Lee if the stud comes out with the nut (most likely locking nut),so be it. There is a bit of shoulder in the center of the stud small vise crip in the center of stud or a jam nut the other side take off the nut from stud. 15mm is factory OE size Clean threads silicone,screw stud back in head followed by the nut. Pete __________________ '91 #1635 PoloGreen 350 LT5 11.09 @ 129.27 11.04 @ 128.86 474RWHP 400RWTQ http://www.youtube.com/watch?v=SFNFOhGGlR4 http://www.youtube.com/watch?v=ZlRIOMwaDYY https://sites.google.com/site/peteszr1garage

04-27-2008	#10
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Pete or AL: Question for you; leaking header stud Pete, I've got $5 that says you can't do that in that amount of space. If you'd like to take me up on my challenge, I'm over in Crystal Lake. Then I'd be willing to bet another $5 you can't retime my cams. LGAFF 92 ZR1 #234 PS: What the Hell is kind of smilie is this ....bad touch, bad touch...this should be banned!