Exhaust leak TPIS...Help!
Thread Starter
Instructor
Joined: Feb 2001
Posts: 192
Likes: 0
From: Arlington Texas
Exhaust leak TPIS...Help!
I have found an exhaust leak on the front tube, driver side. I can slide a post card all the way down it. I checked the torque on the header bolts and they were good at 18 ft/lbs. This is the only tube experiencing this. Should I try to tighten the header bolts up a few ft/lbs or do I need a new gasket or maybe 2 gaskets. The gaskets on there now are the factory stockers...I only hear this noise on accerleration...not during down shifting. At idle it is not present even at cold start up. In neutral rev it up and you can hear it from 1000 to 1500 rmp and then it clears up. Even when I go in reverse I can hear it. Not present at cruising speeds. ANy help much appreciated guys!
ZOOMNZ
ZOOMNZ
Drifting
Joined: May 2003
Posts: 1,715
Likes: 1
From: cAshburn VA
I would: (with the engine cold)
1) get a new header gasket and new (6 I think) header bolts
2) Disconnect battery neg, pull plug wires
3) unbolt air tube from headers
4) unbolt the header from the head
5) remove the old header gasket, clean gasket contact areas.
6) Rotate the header away from the head (TPIS are slip fits, makes this part easy)
7) Clean the heck out of the bolt holes run the appropriate size tap down the holes to make sure the threads are good.
8) Clean the bolt holes again, and again and again... You get the picture.
9) Put on new header gasket and bolt it all back together.
If I'm missing anything others please chime in!
The one thing you DO NOT want to do is over tighten one of the old bolts and break it off in the head. Bad bad thing
A little more work than you might have thought, but best to be thorough...
Let us know what happens...
1) get a new header gasket and new (6 I think) header bolts
2) Disconnect battery neg, pull plug wires
3) unbolt air tube from headers
4) unbolt the header from the head
5) remove the old header gasket, clean gasket contact areas.
6) Rotate the header away from the head (TPIS are slip fits, makes this part easy)
7) Clean the heck out of the bolt holes run the appropriate size tap down the holes to make sure the threads are good.
8) Clean the bolt holes again, and again and again... You get the picture.
9) Put on new header gasket and bolt it all back together.
If I'm missing anything others please chime in!
The one thing you DO NOT want to do is over tighten one of the old bolts and break it off in the head. Bad bad thing
A little more work than you might have thought, but best to be thorough...
Let us know what happens...
Melting Slicks
Joined: May 2000
Posts: 2,974
Likes: 5
From: CenTex Texas
Definitly clean, and re-clean, and re-clean the bolt holes. I've had dirty bolt holes give me false TQ readings before......i learned my lesson when i stripped out a cylinder head bolt hole, and later discovered dirt and oil in the hole. 
Resident moron
Joined: Jun 2003
Posts: 4,746
Likes: 20
From: Assachusetts
Flange may be warped.
Best way to do it, remove the header, and check it on a straightedge (or something similar). If it's warped, get it milled down flat again, and reinstall.
If it's warp bad enough that you can get a card in there, you can re-tighten and double gasket all you want and it's still gonna leak.
Use GM header gaskets. They are re-usable and work excellent (provided the mating surfaces are flat).
Dope
Best way to do it, remove the header, and check it on a straightedge (or something similar). If it's warped, get it milled down flat again, and reinstall.
If it's warp bad enough that you can get a card in there, you can re-tighten and double gasket all you want and it's still gonna leak.
Use GM header gaskets. They are re-usable and work excellent (provided the mating surfaces are flat).
Dope
Drifting
Joined: May 2003
Posts: 1,715
Likes: 1
From: cAshburn VA
Originally Posted by zoomnz
Well how in the heck did the header flange warp!! What would cause it to do that?? Any ideas?
Z
Z
I hadn't even imagined checking for that. Seems in order for that to happen one or more header bolts would have to be loose, a few tight and then the header subjected to high heat, which happens normally at engine operating temperature. But I would have thought the headers would be built to take that, huh... Maybe others have better info on that...
Thread Starter
Instructor
Joined: Feb 2001
Posts: 192
Likes: 0
From: Arlington Texas
Well I havent taken the header off to check but I have loosened all the bolts and re-torqued. And there is a gap that I can slide an index card on the front tube drivers side!! I checked the torque on them before loosening and they were good at 18 ft/lbs. I have noticed that the front header bolt was tight coming out. It also took more than 18 lbs to get the bolt back up to the header. This was with anit-seize on the bolt. That bolt must have been loose (meaning away from the header) but still tight causing the header to warp and start leaking...I dont know all other bolts are good as I checked??? Im really stumped!
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