Exhaust leak after replacing Intake Manifold gaskets

[spradilak]

Start engine. Get underneath, stick your hand up and around the end of the exhaust manifold, where it meets the Y-pipe. If you burn your hand on the escaping exhaust gas, the donut seal is cooked.

Good luck, it'll be no fun getting that apart.

Photos from the same repair on my shorty headers:

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Because the remains of the original bolts are still stuck in the cylinder head?

After the pick test it appears so. I think it's screwed and I'll just leave it alone lol

 

[spradilak]

What bolt broke off in what manifold? Are you talking about an attaching bolt for a component that attached at the intake manifold?

When doing the intake or valve cover gaskets, there is no reason to touch the exhaust manifold or any exhaust at all. The missing bolts on the passenger side are likely broke off and that is why you cannot put new bolts in it. Try to stick a pick in the holes and see if it will stop or not.

You need a mechanic's stethoscope to pinpoint the spot of the leak.

I believe I forgot to reply to this comment. The water neck bolt broke off when replacing he thermostat. Ending up putting a junkyard manifold on. After getting it all back together there's a pretty loud exhaust leak around the engine bay that was no there before.

The passenger side exhaust manifold was missing 2 bolts prior to this job and wasn't making any noise really. I probably could have just left that detail to not cause any confusion..but I believe they are broken off in the head..not gonna mess with those lol.

 

[spradilak]

Gave you pictures to ensure all the vacuum is hooked up correctly..but check out the very last picture..is that the bung for the oxygen sensor?? Also there's quite a large gap at that flange..perhaps it's normal

 

[spradilak]

The last post didn't include these pictures.

 

[spradilak]

Low and behold I'll be a son of a *****..I guess the 02 sensor just fell apart..I apologize for wasting everyone time and thank you for taking the time to try and help me!

 

[termite]

The last post didn't include these pictures.

I'd say you located your exhaust leak with that nice hole in the manifold. Hopefully it won't give you grief getting the remainder out.

 

[movietvet]

As I expected, the exhaust manifold bolts broke off at the head. Is common. There is way more threads in there for sure. Dorman and likely other companies, make an exhaust manifold clamp kit that is made for clamping the ends of exhaust manifolds when the end bolts break. I am unsure if the 1990 5.7 application is included in the list of what they supply. The only other fix is to drill and tap, if there is room or remove head and repair or replace head.

 

[spradilak]

I'd say you located your exhaust leak with that nice hole in the manifold. Hopefully it won't give you grief getting the remainder out.

Yeah hopefully not or I may just jbweld it back in there..maybe that would work.

 

[spradilak]

As I expected, the exhaust manifold bolts broke off at the head. Is common. There is way more threads in there for sure. Dorman and likely other companies, make an exhaust manifold clamp kit that is made for clamping the ends of exhaust manifolds when the end bolts break. I am unsure if the 1990 5.7 application is included in the list of what they supply. The only other fix is to drill and tap, if there is room or remove head and repair or replace head.

I will look into these manifold clamp kits, if not I'll leave it until it becomes a problem. Do these just break off on their own sometimes? I don't believe they've ever been messed with.

 

[spradilak]

As a side question, my wing nut for the air cleaner fell off the truck and into the leaves in the yard and was never found..im sure my lawnmower will find it in the spring..but was size or thread pitch am I looking for in replacement? I've been unable to find this info, although I did see someone in a post say 6mm. I wasn't really able to find that looking online.