Chevy Impala SS Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
976 Posts
Discussion Starter #1
So, a few weeks ago started to hear exhaust leak and figured it was a blown manifold gasket. Had replaced the driver side when I bought the car and all bolts were loose, the gasket was original.
@ that time I tightened the bolts on the passenger side, all seemed fine.

So tore it all apart, and the rearmost port of gasket was totally blown out.
Replaced it, put it all back together and still had a leak.
Figures, nothing is easy for me!

Anyway ripped it all apart again, thinking maybe it was the EGR tube or a blown flange gasket. Nope, not the EGR tube, or the union to exhaust pipe.

When I removed the manifold I found this.





Heat shields removed







Not sure how the thing was even still in one piece LMAO!
 

·
Premium Member
Joined
·
43 Posts
Not sure which year you have but I have my stock manifolds in the garage if you need a set. From a Tuscon and El Paso for life car. Not rusty at all and no cracks. Removed only to install headers. Been sitting in my garage 2-3 years on a shelf in El Paso. Not sure what they would cost to ship. Mine are from a 96.
 

·
Registered
Joined
·
976 Posts
Discussion Starter #3
Not sure which year you have but I have my stock manifolds in the garage if you need a set. From a Tuscon and El Paso for life car. Not rusty at all and no cracks. Removed only to install headers. Been sitting in my garage 2-3 years on a shelf in El Paso. Not sure what they would cost to ship. Mine are from a 96.
Really appreciate the offer, but I had a set from a '96 as well.
I already installed a replacement and all is well...for now anyway.
 

·
Premium Member
Joined
·
43 Posts
No worries. Rather see these things go to a good home then sit on my shelf. Just havent listed them up for offer yet. Glad it got settled. It was a nice crack though.
 

·
Banned
Joined
·
3,437 Posts
did the exh manifold have spacers under the bolt heads on both ends of the manifold ?

should be 4 spacers on each side .

when my bolt broke off I had to fabricate a spacer on driver side.
 

·
Registered
Joined
·
1,624 Posts
Bovineplane, what would you want shipped for your exhaust manifolds to 94566, I'm very afraid I have the same issue as the OP? I have an exhaust leak on the passenger side as well and I've replaced the gasket awhile back and now it's getting worse.
 

·
Registered
Joined
·
976 Posts
Discussion Starter #7
did the exh manifold have spacers under the bolt heads on both ends of the manifold ?

should be 4 spacers on each side .

when my bolt broke off I had to fabricate a spacer on driver side.
Yes, spacers were there, judging by the condition/gasket probably original and untouched since assembled.
 

·
Registered
Joined
·
7,809 Posts
Yes, spacers were there, judging by the condition/gasket probably original and untouched since assembled.

Bronze and frame that sucker! That manifold sacrificed itself to save you a broke bolt.
 

·
Banned
Joined
·
3,437 Posts
Bronze and frame that sucker! That manifold sacrificed itself to save you a broke bolt.
when I fabricated the missing spacer I was concerned about the spacer not moving with the manifold having a rusted surface so I placed a thin s/steel washer on the manifold so the spacer could move on a smooth surface.

the other thing I did was used a 1/4 in drive to tighten the stud .. then started the engine and got it up to temp then after a few min torqued it to the spec # I think 20ft lbs approx..GM used a med lock tight on these bolts not anti seize ..
 

·
Premium Member
Joined
·
589 Posts
I cut off the casting tie bar btw the 2 sections of manifold.Every one I've seen that has cracked,had the tie bar.

Good catch t-shooting and good photos.

Jim
 

·
Registered
Joined
·
976 Posts
Discussion Starter #11
Big problem with these is the heat shields cover almost entire manifold.
I recall trying to examine it from underneath but never saw this crack.
Only visible after removed and heat shields hid the extent of it.
I could hear leak with length of hose to my ear but not exact location.
 

·
Registered
Joined
·
90 Posts
not sure where you are in Cali but just saw a a guy post a set of coated Hookers for about 5 bills on c-list, not the cheap alternative especially when free stocks are offered but...
 

·
Registered
Joined
·
976 Posts
Discussion Starter #13 (Edited)
No interest in headers on this thing @ moment. On my stock-ish motor the gains would be so small.
I'd make larger cat pipes, and hog out manifold outlets and call it good.

Maybe later down road when get new motor in?
 

·
Registered
Joined
·
1,457 Posts
I cut off the casting tie bar btw the 2 sections of manifold.
Every one I've seen that has cracked, had the tie bar.
GM actually mentioned this in a TSB (don't remember if it was the same one as the broken bolt TSB).
Cut the tie bars.
 

·
Registered
Joined
·
1,145 Posts
OP, how was your fuel economy? Have you noticed a change after replacement?
 
1 - 16 of 16 Posts
Top