Exhaust/valve tick

[maxtwms]

Maybe I'm being picky but I just had my exhaust replaced. I asked them to look for leaks. he said he forgot but stuck his hand around a few places and told be he's sure it's just a valve tick. I relashed the valves with the egine running today and after it warmed up, the tick was back. WTH am I missing other than demanding the y find the leak? If it's the manifolds... I thought the tick would go away after it warms and expands. At worst case, manifold swap, what can I get? No headers please.. too many horror stories.

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[1987 GMC Jimmy]

I’ve checked for exhaust leaks by getting a vacuum cleaner hose, wrapping an old t-shirt around it, and sticking it in the tailpipe. You can’t do it for terribly long intervals for the sake of the vacuum cleaner motor, though, because it gets hot. “I forgot” shouldn’t be in any professional wrencher’s vocabulary. I would consider another mechanic in the future. If everything looked good during the valve lash, and everything was moving like it should, I doubt it’s a stuck lifter. You can check for a burnt exhaust valve by placing a piece of paper behind the tailpipe and seeing if it gets sucked in. I feel like you’d have better luck trying to find the leak on your own first. If you find one, then go deal with the “mechanic.” If you’re looking for an upgrade, word on the street is the pre-smog era ram horn manifolds are the best. Otherwise, it could be as simple as a missing manifold stud or a bad gasket on either end of the manifold(s).

Oh, and if you still have the EFE valve on the passenger side manifold, those can crumble internally and start making all kinds of noise. If it is that, you can get a piece of baling wire, tie the valve open, and remove the vacuum going to it.

 

[maxtwms]

Damnit I've read that no telling how many times and I specifically told the muffler man, if u will, to check that efe valve. " I think it may be the leak" and he says "oh I forgot to mention that. Well it could just be a loose valve" fair enough..... This guy does good work but lazy on his part to diagnose. Albeit I just pop in and demand service. I do feel like a bad student to keep dismissing the efe valve on my own accord though. I got under the truck and felt that it was in the open position but in hindsight, the bad part is that I can actuate it. It should be properly closed. End of story. So thank all y'all and apologies.

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H

 

[1987 GMC Jimmy]

Damnit I've read that no telling how many times and I specifically told the muffler man, if u will, to check that efe valve. " I think it may be the leak" and he says "oh I forgot to mention that. Well it could just be a loose valve" fair enough..... This guy does good work but lazy on his part to diagnose. Albeit I just pop in and demand service. I do feel like a bad student to keep dismissing the efe valve on my own accord though. I got under the truck and felt that it was in the open position but in hindsight, the bad part is that I can actuate it. It should be properly closed. End of story. So thank all y'all and apologies.

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H

Wait, so it’s stuck open, but you can move it? Even if it’s still working, it can make noise. I suspected mine, and while I couldn’t 100% confirm, I just tied it open anyway. I think it’s designed to work in conjunction with the heat stove and riser tube that go to the thermal apparatus in the air cleaner, and I don’t think it would provide any benefit except if all of it was there, everything was working, and it was cold. If you had a mechanic’s stethoscope, you could probe it and confirm it for sure, but I’m thinking just get rid of it functionally.

 

[maxtwms]

All my emission stuff is gone. What I gather is that I shoul AT LEAST tie it off strong

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[Rusty Nail]

Dude.
Pull it out and remove the valve "flap", leave the rest of it alone, and put it back where it came from. I THINK it's beveled on the exit side and flat on the upstream side, so a donut gasket IS necessary.

Pretty sure.

The EfE is 2 inches thick or so, you can't NOT put it back without exhaust work.


Maybe you have a sticky lifter...
Substitute one quart motor oil for one quart DEX 3 and forget about it until lifter unsticks.

Hope this helps!

 

[Craig 85]

Does your EFE look like this one? This is the part number used on my 454. FYI when no vacuum is applied to the valve, it's in the open position like pictured. If I recall the old bi-metal ones are closed until they heat up. I'm not sure the size of your exhaust, but Eckler's Corvette carries these spacers without flappers for small and big blocks.
https://www.ecklerscorvette.com/corvette-exhaust-spacer-manifold-to-pipe-right-1957-1974.html
https://www.ecklerscorvette.com/corvette-exhaust-spacer-manifold-to-pipe-right-1962-1974.html

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[78C10BigTen]

Does your EFE look like this one? This is the part number used on my 454. FYI when no vacuum is applied to the valve, it's in the open position like pictured. If I recall the old bi-metal ones are closed until they heat up. I'm not sure the size of your exhaust, but Eckler's Corvette carries these spacers without flappers for small and big blocks.
https://www.ecklerscorvette.com/corvette-exhaust-spacer-manifold-to-pipe-right-1957-1974.html
https://www.ecklerscorvette.com/corvette-exhaust-spacer-manifold-to-pipe-right-1962-1974.html

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My 78 big ten had one of those on the passenger side pipe but was not vaccum actuated. It was the first time i had seen anything like it. I eliminated it as i planned headers so... i do still have it laying somewhere.

 

[Craig 85]

My 78 big ten had one of those on the passenger side pipe but was not vaccum actuated. It was the first time i had seen anything like it. I eliminated it as i planned headers so... i do still have it laying somewhere.

This is what my '79 SBC looked like. Pretty similar to my '85, but the vacuum valve is above the valve cover and had a rod down to the flapper valve at the bottom of the exhaust manifold.

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[78C10BigTen]

This is what my '79 SBC looked like. Pretty similar to my '85, but the vacuum valve is above the valve cover and had a rod down to the flapper valve at the bottom of the exhaust manifold.

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Mine didnt look like that being a big 10, no emisssions. It had the normal long bugle style air cleaner without the tube and didnt have the big vaccum thing or in your case the egr looking silver thing. But mine also was swapped from a qjunk to an edelbrock so im not sure what all was removed.

 

[maxtwms]

So I'm afraid to try to pull mine off to replace for fear I'll shear off a stud or two. I think I'm just going to tie it open for the moment and see if it makes the tick a little better... Unfortunately, I don't know what is open and what is closed. There's about an inch long flat blade that's connected to the actuator rod and I feels like when that blade is in line with the tubing, the valve is open. Does this seem right?

Side note - I've been having issues with stalling while my ac is on. It's partly from low idle and poor takeoff clutch work from bad habits (always scared of wearing out my clutch) but the other day I stalled and couldn't get it started for about 30 minutes... Eventually adjusted my idle up from where it was 700 to about 780. I had spark (checked with timing gun), fuel was being dumped in the carb, didn't smell like gas (like it was flooded) and the crank was strong. Could the flap have been closed the whole time I drove for about 30 mins and never opened? When it did start it sputtered around 300 until it finally leveled out. I know I got a lot of silly issues but I just don't know enough to realize there's not a fire and something simple is causing issues...

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[Rusty Nail]

Don't be scared ol boy! If you break it, that only means you get to fix it!

 

[maxtwms]

Dammit. I'm sitting here contemplating just sucking it up. Only problem is it's my DD at the moment... I may just soak it in pbb and give a few tugs... If that feels to scary I reckon I'll get the torch. Is it really as easy as pulling off the nuts, sliding the efe out, sliding a donut/gasket in and calling it a day?

Don't be scared ol boy! If you break it, that only means you get to fix it!

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[Obwonkonobe]

I’d be willing to bet that no matter what you do, the linkage is so worn that it’ll always tick..
That was the case with mine so I yanked it, hacked out the flapper (a death wheel made easy work of that) and welded the holes shut, but if you can’t weld you may be able to just throw a bolt or 2 in the open holes from the shaft.

Needless to say that simplicity is always the best answer with these trucks, I haven’t had to think about my exhaust since

 

[maxtwms]

So, inline with exhaust is open? Asking for a friend..he just needs to get to work in the morning! ;-)

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