uhh what now? (exhaust issues) (Page 1/2)
cartercarbaficionado SEP 16, 03:02 AM
I just got the Tangerine in the shop again and I replaced the rear manifold with one from my stash since the person driving was so tired of hearing it.
anyways the rear manifold bolt hole had always had a bit of an issue and uh yeah not sure what I'm supposed to do now. I do have a spare head but not looking to tear back Into this engine so I think I'm gonna try to make a ls style bolt repair clamp and see what happens. worst case now is another leak
cartercarbaficionado SEP 16, 04:36 AM
good enough I think?
edit: after a very hard spirited drive that was definitely alot harder than how it's normally driven it still has a small exhaust leak somewhere on the rear manifold and it's connections despite being checked for flatness and then being made flat. so not sure what I'm gonna do about that yet

[This message has been edited by cartercarbaficionado (edited 09-16-2024).]

Dennis LaGrua SEP 16, 06:03 AM
The 2.8L exhaust manifold bolts have a habit of rusting in place after 40 years. They sit in a bad environment and its a moist one. The solution is trying to secure the GM drill fixture that will allow the broken bolt studs to be drilled out and removed. You might try applying heat before pulling the bolt but working in tight quarters is hard.
Ed Parks used to weld a "T" across the broken stud and then used a slotted socket to turn the stud out. Either way this is a pretty difficult job.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

cartercarbaficionado SEP 16, 06:22 AM

quote
Originally posted by Dennis LaGrua:

The 2.8L exhaust manifold bolts have a habit of rusting in place after 40 years. They sit in a bad environment and its a moist one. The solution is trying to secure the GM drill fixture that will allow the broken bolt studs to be drilled out and removed. You might try applying heat before pulling the bolt but working in tight quarters is hard.
Ed Parks used to weld a "T" across the broken stud and then used a slotted socket to turn the stud out. Either way this is a pretty difficult job.



the rest came out with no fuss and thus bolt hole has had an issue since before i bought the car. also how the heck am I supposed to use a drilling jig to fix a broken head. the actual material around the bolts threads broke and shattered
Dennis LaGrua SEP 16, 09:07 PM

quote
Originally posted by cartercarbaficionado:

the rest came out with no fuss and thus bolt hole has had an issue since before i bought the car. also how the heck am I supposed to use a drilling jig to fix a broken head. the actual material around the bolts threads broke and shattered


The stud must be removed as you can't fix it. The GM drilling jig centers a LH rotation carbide drill bit on the broken stud that is threaded in the manifold hole. Once the hole is drilled a screw extractor is used to get the stud out. GM had loads of trouble with broken exhaust manifold bolts during the recall where a heat shield was installed. The jig was supplied to all Pontiac dealerships where the recall work was done. They occasionally have been been sold on eBay.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

shemdogg SEP 16, 10:31 PM
I had that happen on my kit car and someone here recommended welding the stud to the head. Thats what I did and it worked great! Also had a hairline crack on the manifold and a broken bracket. Theres a pic about 1/3 of the way down on page 2 of operation turd polish.

shem
1985 Fiero GT SEP 16, 11:40 PM

quote
Originally posted by Dennis LaGrua:

The stud must be removed as you can't fix it. The GM drilling jig centers a LH rotation carbide drill bit on the broken stud that is threaded in the manifold hole. Once the hole is drilled a screw extractor is used to get the stud out. GM had loads of trouble with broken exhaust manifold bolts during the recall where a heat shield was installed. The jig was supplied to all Pontiac dealerships where the recall work was done. They occasionally have been been sold on eBay.





The stud is removed along with half the threads, as the head broke, leaving half a bolt hole that is unusable.
cartercarbaficionado SEP 17, 04:07 AM

quote
Originally posted by 1985 Fiero GT:


The stud is removed along with half the threads, as the head broke, leaving half a bolt hole that is unusable.


thank you. the clamp is actually working better than the bolt or stud ever did (it was a 3800 exhaust bolt when I bought the car)
cartercarbaficionado SEP 17, 04:11 AM

quote
Originally posted by shemdogg:

I had that happen on my kit car and someone here recommended welding the stud to the head. Thats what I did and it worked great! Also had a hairline crack on the manifold and a broken bracket. Theres a pic about 1/3 of the way down on page 2 of operation turd polish.

shem


that would have been a good idea if I had a tig welder to localize the heat better in the casting or had it apart. remember this is cast iron and this whole casting on mine is contaminated so If I'm welding it then it's coming off to be preheated in an oven then slowly cooled over a few days after welding to allow the stresses to minimize after using filler intended for attaching dissimilar materials together
Yellow-88 SEP 20, 04:10 PM
How much iron is there at the bottom of that hole? Is there possibly enough to get a few more threads in there? How can one find out?
So are you feelin lucky?