Replacing Exhaust Manifold Gasket
Thread Starter
Intermediate
Joined: Jul 2015
Posts: 38
Likes: 0
Replacing Exhaust Manifold Gasket
Hello, I need to swap out the manifold gasket on the passenger side of my '87 C4. Seems like a straight forward job but just a few questions. Is there any hints anyone can give me before starting this? Any out of the ordinary tools I may need, thinks look a bit tight towards the rear bolt. I really don't want to pay a mechanic to do such a normally simple task. Then again, I love my c4 and don't wanna botch anything up. Thanks !
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Mix up a mixture of 50% ATF and 50% Acetone and brush on the bolts to the exhaust manifold/heads. Let this sit for a day, apply more if you can during this time period. This will help break the bolts loose. You can probably get these bolts out and pull the old gasket out and put the new one in.
Thread Starter
Intermediate
Joined: Jul 2015
Posts: 38
Likes: 0
Mix up a mixture of 50% ATF and 50% Acetone and brush on the bolts to the exhaust manifold/heads. Let this sit for a day, apply more if you can during this time period. This will help break the bolts loose. You can probably get these bolts out and pull the old gasket out and put the new one in.
Thanks for the suggestion. Would PB Blaster penetrating oil do the trick as well?
Oil Producer
Joined: Apr 2014
Posts: 9,380
Likes: 2,744
absolutely. i just did this on my 85 while doing the head gasket. all of my bolts came out no trouble but i left them soak for 3 days. i shot each bolt in the morning and let it sit. they came out no problem.
You should be able to get the gaskets out without removing the manifold.
you might need to undo the bolts on the flange at the bottom of the manifold right where it enters into the Y pipe. douse these with penetrating oil from the top, and the bottom in case you do.
when you run the car again, the pb will burn off the exhaust for a bit and cause a smell.
good luck, post with any issues.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
PB Blaster will work. But check this out for some data.....
Machinist's Workshop magazine recently published some information on various penetrating oils that I found very interesting.
Some of you might appreciate this. The magazine reports they tested penetrates for break out torque on rusted nuts.
They arranged a subjective test of all the popular penetrates with the control being the torque required to remove the nut from a
"scientifically rusted" environment.
*Penetrating oils ........... Average torque load to loosen*
No Oil used ................... 516 pounds
WD-40 ..................... ... 238 pounds
PB Blaster .................... 214 pounds
Liquid Wrench ...............127 pounds
Kano Kroil .................... 106 pounds
ATF*-Acetone mix............53 pounds
The ATF-Acetone mix is a "home brew" mix of 50 - 50 automatic transmission fluid and acetone.
Note this "home brew" released bolts better than any commercial product in this one particular test.
Our local machinist group mixed up a batch and we all now use it with equally good results.
Note also that "Liquid Wrench" is almost as good as "Kroil"
for about 20% of the price.
Steve from Godwin-Singer says that ATF-Acetone mix is best, but you can also use ATF and lacquer thinner in a 50-50 mix.
*ATF=Automatic Transmission Fluid
Machinist's Workshop magazine recently published some information on various penetrating oils that I found very interesting.
Some of you might appreciate this. The magazine reports they tested penetrates for break out torque on rusted nuts.
They arranged a subjective test of all the popular penetrates with the control being the torque required to remove the nut from a
"scientifically rusted" environment.
*Penetrating oils ........... Average torque load to loosen*
No Oil used ................... 516 pounds
WD-40 ..................... ... 238 pounds
PB Blaster .................... 214 pounds
Liquid Wrench ...............127 pounds
Kano Kroil .................... 106 pounds
ATF*-Acetone mix............53 pounds
The ATF-Acetone mix is a "home brew" mix of 50 - 50 automatic transmission fluid and acetone.
Note this "home brew" released bolts better than any commercial product in this one particular test.
Our local machinist group mixed up a batch and we all now use it with equally good results.
Note also that "Liquid Wrench" is almost as good as "Kroil"
for about 20% of the price.
Steve from Godwin-Singer says that ATF-Acetone mix is best, but you can also use ATF and lacquer thinner in a 50-50 mix.
*ATF=Automatic Transmission Fluid
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 764
I bought these fel-pro exhaust manifold gaskets for my 85 - more like the original equipment -
BTW, I removed my exhaust manifold bolts without the aid of any penetrating oil. even after 30 years, all bolts came out without any excessive effort. all bolts were original to the car as installed by the factory. I wouldn't think anyone would have problems with iron head L98's - aluminum heads, yes, iron heads, no.
BTW, I removed my exhaust manifold bolts without the aid of any penetrating oil. even after 30 years, all bolts came out without any excessive effort. all bolts were original to the car as installed by the factory. I wouldn't think anyone would have problems with iron head L98's - aluminum heads, yes, iron heads, no.
Last edited by Joe C; Dec 11, 2015 at 03:31 PM.
Thread Starter
Intermediate
Joined: Jul 2015
Posts: 38
Likes: 0
pb blaster will work. But check this out for some data.....
machinist's workshop magazine recently published some information on various penetrating oils that i found very interesting.
some of you might appreciate this. The magazine reports they tested penetrates for break out torque on rusted nuts.
they arranged a subjective test of all the popular penetrates with the control being the torque required to remove the nut from a
"scientifically rusted" environment.
*penetrating oils ........... Average torque load to loosen*
no oil used ................... 516 pounds
wd-40 ..................... ... 238 pounds
pb blaster .................... 214 pounds
liquid wrench ...............127 pounds
kano kroil .................... 106 pounds
atf*-acetone mix............53 pounds
the atf-acetone mix is a "home brew" mix of 50 - 50 automatic transmission fluid and acetone.
note this "home brew" released bolts better than any commercial product in this one particular test.
our local machinist group mixed up a batch and we all now use it with equally good results.
note also that "liquid wrench" is almost as good as "kroil"
for about 20% of the price.
steve from godwin-singer says that atf-acetone mix is best, but you can also use atf and lacquer thinner in a 50-50 mix.
*atf=automatic transmission fluid
machinist's workshop magazine recently published some information on various penetrating oils that i found very interesting.
some of you might appreciate this. The magazine reports they tested penetrates for break out torque on rusted nuts.
they arranged a subjective test of all the popular penetrates with the control being the torque required to remove the nut from a
"scientifically rusted" environment.
*penetrating oils ........... Average torque load to loosen*
no oil used ................... 516 pounds
wd-40 ..................... ... 238 pounds
pb blaster .................... 214 pounds
liquid wrench ...............127 pounds
kano kroil .................... 106 pounds
atf*-acetone mix............53 pounds
the atf-acetone mix is a "home brew" mix of 50 - 50 automatic transmission fluid and acetone.
note this "home brew" released bolts better than any commercial product in this one particular test.
our local machinist group mixed up a batch and we all now use it with equally good results.
note also that "liquid wrench" is almost as good as "kroil"
for about 20% of the price.
steve from godwin-singer says that atf-acetone mix is best, but you can also use atf and lacquer thinner in a 50-50 mix.
*atf=automatic transmission fluid
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Oil Producer
Joined: Apr 2014
Posts: 9,380
Likes: 2,744
Thanks for this Jmark! As i work on my vette, it IS starting to grind on me how much i spend on "consumables" like pb.
Id be happy to try this mixture. does anybody know if there is a plastic spray bottle that will hold the acetone/atf mix?
or some way to use a metal can and shoot compressed air into it?
Id be happy to try this mixture. does anybody know if there is a plastic spray bottle that will hold the acetone/atf mix?
or some way to use a metal can and shoot compressed air into it?
PB Blaster will work. But check this out for some data.....
Machinist's Workshop magazine recently published some information on various penetrating oils that I found very interesting.
Some of you might appreciate this. The magazine reports they tested penetrates for break out torque on rusted nuts.
They arranged a subjective test of all the popular penetrates with the control being the torque required to remove the nut from a
"scientifically rusted" environment.
*Penetrating oils ........... Average torque load to loosen*
No Oil used ................... 516 pounds
WD-40 ..................... ... 238 pounds
PB Blaster .................... 214 pounds
Liquid Wrench ...............127 pounds
Kano Kroil .................... 106 pounds
ATF*-Acetone mix............53 pounds
The ATF-Acetone mix is a "home brew" mix of 50 - 50 automatic transmission fluid and acetone.
Note this "home brew" released bolts better than any commercial product in this one particular test.
Our local machinist group mixed up a batch and we all now use it with equally good results.
Note also that "Liquid Wrench" is almost as good as "Kroil"
for about 20% of the price.
Steve from Godwin-Singer says that ATF-Acetone mix is best, but you can also use ATF and lacquer thinner in a 50-50 mix.
*ATF=Automatic Transmission Fluid
Machinist's Workshop magazine recently published some information on various penetrating oils that I found very interesting.
Some of you might appreciate this. The magazine reports they tested penetrates for break out torque on rusted nuts.
They arranged a subjective test of all the popular penetrates with the control being the torque required to remove the nut from a
"scientifically rusted" environment.
*Penetrating oils ........... Average torque load to loosen*
No Oil used ................... 516 pounds
WD-40 ..................... ... 238 pounds
PB Blaster .................... 214 pounds
Liquid Wrench ...............127 pounds
Kano Kroil .................... 106 pounds
ATF*-Acetone mix............53 pounds
The ATF-Acetone mix is a "home brew" mix of 50 - 50 automatic transmission fluid and acetone.
Note this "home brew" released bolts better than any commercial product in this one particular test.
Our local machinist group mixed up a batch and we all now use it with equally good results.
Note also that "Liquid Wrench" is almost as good as "Kroil"
for about 20% of the price.
Steve from Godwin-Singer says that ATF-Acetone mix is best, but you can also use ATF and lacquer thinner in a 50-50 mix.
*ATF=Automatic Transmission Fluid
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
It is like preventative medicine....better to use it and have no problem than to break off a bolt if you didn't use it.
You could try this to apply...
http://www.kbctools.com/products/FLU...LERS/3270.aspx
Or for those with compressed air....
http://www.kbctools.com/products/FLU...YERS/3285.aspx
You could try this to apply...
http://www.kbctools.com/products/FLU...LERS/3270.aspx
Or for those with compressed air....
http://www.kbctools.com/products/FLU...YERS/3285.aspx
Last edited by John A. Marker; Dec 11, 2015 at 04:23 PM.
Oil Producer
Joined: Apr 2014
Posts: 9,380
Likes: 2,744
Amen!!!
"dropping" the exhaust on my 85 turned into helicoiling 4 (FOUR!!!) manifold flange bolts and 1 on the back of the cat.
Bleh! never again!
found a sweet chrisfix vid on this. going to get an old oiler can!
"dropping" the exhaust on my 85 turned into helicoiling 4 (FOUR!!!) manifold flange bolts and 1 on the back of the cat.
Bleh! never again!
found a sweet chrisfix vid on this. going to get an old oiler can!
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 764
if you need exhaust manifold studs (m10-1.5), here's a dorman part that I used on my 85. perfect fit to originals, and far cheaper than GM OEM -
Dorman 675-352 Double Ended Stud
goop them up with plenty of high-temp anti-seize. I also used copper, flange lock nuts. they were a BMW part, but far better than the plain old GM stuff -
BMW p/n 18301737774
Last edited by Joe C; Dec 12, 2015 at 06:00 AM.
Thread Starter
Intermediate
Joined: Jul 2015
Posts: 38
Likes: 0
Thanks all. I hit them with the PB just to see if that would do the trick. They broke loose with some effort but smoothly. One piece gasket slid right in. One leak down, I suspect the Y pipe needs to be snugged up along w a new EGR gasket... Wasn't in stock when I picked up the manifold gasket.
Thanks for the help. I'm the new kid on the block so I will be posting a quick 'hello this me' post soon.
Thanks for the help. I'm the new kid on the block so I will be posting a quick 'hello this me' post soon.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Glad it went well. Hit the studs on the "Y" with your PB Blaster and let it sit. These studs are often worse than the exhaust manifold bolt. Mostly because they are almost 100% exposed to the elements plus the head and cooling of the pipe.
1st Gear
Joined: Feb 2021
Posts: 1
Likes: 0
Here is about CNC,wish I could help you
The newly introduced rotary tables of the 4th and 5th axes from DEX.
Strict standards in all manufacturing processes and provide satisfactory after sales services to customers all over the world.
The positioning accuracy, structural rigidity and service life of our products are as good as those of our competitors in Europe, Japan and the USA.
This is why so many manufacturers choose DEX products.
Their prouduction are cam Indexer,rotary table,Automatic tool changer,and so on.
Strict standards in all manufacturing processes and provide satisfactory after sales services to customers all over the world.
The positioning accuracy, structural rigidity and service life of our products are as good as those of our competitors in Europe, Japan and the USA.
This is why so many manufacturers choose DEX products.
Their prouduction are cam Indexer,rotary table,Automatic tool changer,and so on.