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Discussion Starter · #1 ·
Whats up fellas,
I consider myself to be a decent shadetree mechanic but every one in a while I do more damage than good. When prepping the car for CA smog last year I ran through the typical tune up items then tackled welding on the car for the first time. I had two broken bolts on the DS exh manifold. I was 1 for 2 with the bolts and couldnt get the one nearest the firewall. The bolt broke inside the head about 1/4" inch in so getting a bead on the bolt and nut was kinda hard. Never got a bead on strong enough to take the twisting while trying to back out the bolt.
Anyway, about 1500 miles later the broken bolt and double gasket is starting to fail. Why dbl gasket? Because while welding I used flux core wire so you could imagine the mess it made on the head. Even caught my firewall on fire twice. My fail: In attempts to clean up the slag I over grinded down the manifold boss probably around 1/8". The gaskets held up ok but there was always a high pitch blow by while revving and a wallow like an imbalanced tire on the highway.

This morning on start up the leak seemed throw off the knock sensor and retards timing. After warming up, the leak lessens and drives normally. Last i checked fuel trim was less than 3% so the leak doesn't seem to effect the A/F mix.
The proper fix would be to pull the head and have the bosses leveled but the long block is up in age so might as well pull and rebuild for the effort.

Short of yanking the block or heads, curious if there is a JB weld type of "bondo" that I could use to level the exhaust boss on that port in the interim?

Thx and don't act like you've never any side effects to your physical therapy, lol!
 

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when the bolts break inside the head slightly best use the reverse drill bits. using the exhaust manifold as a guide and a piece of tubing as a collar to hold the bit in the middle of the broken bolt since the bolt metal will be distorted at the break. most times the bolt will come out as the bit cuts backwards. use small sized bits 1/8 etc..

when the bolt is showing then you can weld on the stud for removal.

could be you will need a new manifold if it has distorted.
 

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A big +1 on reverse bit. Took a while to order, but worked great to back itself right out while still drilling. Another plus one on jcat's collar guide idea. Got offcenter into the head on one and took hours with a micro chisel to work that one out.

And of course a rightangle drill, but everyone knows that.
 

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Discussion Starter · #4 ·
Good stuff guys, right angle drill? Might have to pull out the 20% harbor freight coupon for this one,lol. Wonder if they have strong enough reverse bits too?
Will find out soon and willreport back

I didn't think about bothering with that bolt again but getting the bolt out will make my drive much better, having no exhaust ticking would be nice.

Thx!
 

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Good stuff guys, right angle drill? Might have to pull out the 20% harbor freight coupon for this one,lol. Wonder if they have strong enough reverse bits too?
Will find out soon and willreport back

I didn't think about bothering with that bolt again but getting the bolt out will make my drive much better, having no exhaust ticking would be nice.

Thx!
see if you can find a 90 deg adapter to connect to a standard power drill. you do not need high power just for a small drill bit.

having a reverse cobalt bit would be nice .. harbor fright does not have reverse bits. in my area a tool supply house has them.
 

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OP

Not quite clear on what you ground down to far, the head or the exhaust manifold. If the manifold just get another at junk yard. If head, ouch.

For a "fix it in a can" type deal you could try exhaust putty/paste/compound they have various brands at auto part stores. Typically used to patch cracked mufflers but they do have some stuff for very high temps. Maybe apply like patching drywall and use a putty knife to flatten/smooth then sand flat with a block of wood and course sand paper. Yeah this may be ghetto but "may" resolve your problem once you do get the broken bolt out. Use FelPro exhaust gaskets

If you are yanking the manifold to try and fix this with head on car, I would get new (better) bolts
 

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Discussion Starter · #7 ·
OP

Not quite clear on what you ground down to far, the head or the exhaust manifold. If the manifold just get another at junk yard. If head, ouch.

For a "fix it in a can" type deal you could try exhaust putty/paste/compound they have various brands at auto part stores. Typically used to patch cracked mufflers but they do have some stuff for very high temps. Maybe apply like patching drywall and use a putty knife to flatten/smooth then sand flat with a block of wood and course sand paper. Yeah this may be ghetto but "may" resolve your problem once you do get the broken bolt out. Use FelPro exhaust gaskets

If you are yanking the manifold to try and fix this with head on car, I would get new (better) bolts
ouch indeed, originally the 2 bolts were broken off on the #7 exhaust port. I pulled my HF welder out of the box, wired it up, spattered up the head(got front bolt out but never managed to get the one nearest the firewall.
I thought I had pics of it to show but I don't. It's kind of a tough angle so I was taking pics of the nut to make sure they were centered on the broken bolt. After burning through about 10 stainless steel nuts I through in the towel replaced all bolts with grade 10 or thereabouts bolts and doubled up on the gasket. It got me to pass CA emmissions and fuel trim still seems to be in line except for cold start up.

Oh ya, so the spatter was on heavy so I took a grinder to the head to gently shave it off but it seems I got happy with it and took off too much mtrl. I "think" a little resurfacting of all exhaust boss's would work but that means taking off the heads, not in short term SS plan.

So with the 5 bolts currently on, i just was looking to level the manifold/head mating surface so the manifold flange would have more material to squish the gasket against. The blow by is starting to weaken the gasket and knocking loud enough to trip the knock sensor, but only until it warms. Having the bolt out and "puttying" the gap is optimal, i might just try both this weekend.

thanks
 
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