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need help with 1967 DeVille exhaust manifold situation

Started by caddychap, July 24, 2012, 04:56:20 PM

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caddychap

The middle exhaust manifold gasket on the passenger side has crumbled away, leaving a gap which emits a bad puffing/chugging sound.  I bought a FelPro gasket set and I was luckily able to remove the two bolts from the middle of the exhaust manifold without any trouble.  I figured I would just slip in the new gasket and put the bolts back in.  However, when I tried to slip in the gasket, it would not go in because there seems to be two guide pins toward the back of the head where it mates up to the exhaust manifold.  I used a thin piece of metal as a feeler, and that's what it feels like.  Am I correct that there are such guide pins?  If so, I guess I have to remove the entire exhaust manifold to put the new gasket in?  Any help/suggestions are appreciated.  Thanks, Jon

Alan Harris CLC#1513

I will warn you that there is a very good chance that the manifold has warped over the years and that that is why the gasket crumbled. You need to remove the manifold in any case to check the mounting surface for flatness.

If it is not flat, you can have it machined.

cadillactim

There are no guide pins that I am aware of. All that hold the manifold to the head are the bolts. You may need to loosen the other bolts to get enough room to install the gasket.

Make sure your heat riser isn't stuck, causing excessive heat, which will burn out gaskets. Common problem on these engines.

Tim
Tim Groves

caddychap

#3
Dumb question, but are there more than two bolts at each point where the exhaust manifold bolts to the head?

Seans 66

My recommendation would be to pull the whole thing, have the mainfold checked for straightness and if its warped, have it surfaced.  Clean the mating area on the heads up and put new gaskets on all ports.  A bit more work but it will take you much less time in the long run and give you a repair you can trust.

caddychap

Thanks Sean, I may do that.  In the meantime, I am still curious as to whether there are any guide pins or more than two bolts per port.  Anybody know?

R Schroeder

Wouldn't the new gasket show you all of the mounting holes ?
I would think if there were more than the bolt holes it would be possible.
Don't know for sure.
Roy

caddychap

That's what I thought, Roy. The gasket has two holes which the 2 bolts I removed will pass through. But there are these 2 additional pins further back. I will mess with it more this weekend and try to figure it out. It just doesn't make sense, and the shop manual isn't giving me any answers.

Joe G 12138

I've done this on many 429's many times. As Sean said, there's nothing but bolts holding the manifold on. As Roy said, if there were pins there would be holes in the gaskets. You're feeling old gasket bits or rust scale down there. If you have enough clearance to sneak in a gasket, you WILL crack the exhaust manifold when you tighten it down on almost ANY engine. Then you get to pull it off anyway to replace it and all three gaskets anyway. There is no shortcut on this job. Exhaust pipe off +6 bolts= manifold off. Clean all surfaces, use 3 NEW gaskets which are all the same thickness. 6 bolts on, exhaust pipe back on= done.
Joe Gibeault

The Tassie Devil(le)

'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

35-709

1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

Bob Hoffmann CLC#96

1968 Eldorado slick top ,white/red interior
2015 Holden Ute HSV Maloo red/black interior.
             
Too much fun is more than you can have.

The Tassie Devil(le)

Looks like the person that dragged it up removed his posting as my request in asking what is it, now means totally nothing.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

caddychap

#13
I tried several times to post this reply but only the word IT appeared. So I am posting with no commas or apostrophes. And yes it has been 9 years but I wanted to post an update in case it can help someone else. This weekend I finally tackled this project. Joe G you were right on the money. The only thing to do was just roll up my sleeves and take off the exhaust manifold. Luckily all 6 bolts came out with no problem. I slipped in the new gaskets and tightened the bolts. Now the car runs much quieter of course. I cant believe I was dumb enough to think that there were guide pins in there. It was just old gasket material that I was able to scrape out with a paint scraper. Thank you to all who helped me with this! Now you know what IT is! ;D

Joe G 12138

YOU ARE VERY WELCOME Jon!  And unlike some others; I really appreciate and enjoy hearing the results of the "Tech" solutions offered on this forum be they successes or failures....even if YEARS later.  Many contributors  take the time to offer their experience, research, or opinions without ever hearing from the original poster of the question again.  We're all still learning.  Thanks for the follow up!!!!  Joe Gibeault