Kartman01 Posted January 26, 2021 Share Posted January 26, 2021 I am getting close to wrapping up addressing some of the issues I uncovered in my 1950 Buick Estate Wagon. One vexing problem I cannot seem to track down is an unusual amount of engine noise under acceleration. To my ears, it sounds more like exhaust noise than intake noise. I have checked the exhaust manifold, it is tight and square with no apparent leaks. The car has a very tight exhaust system and a proper OEM-style muffler. Are there areas on the firewall inside the passenger compartment that should have some kind of insulation? The floorboards have the correct jute padding and carpet, so no issues there. Are there any covers or insulating gaskets I sould look for that may be missing? I have not noticed anything, but I will admit that I don't know what is supposed to be there and what is not! Thanks in advnace for any help! Link to comment Share on other sites More sharing options...
Bill Stoneberg Posted January 26, 2021 Share Posted January 26, 2021 Is the firewall insulator still on the car ? It goes on the inside of the car up against the firewall. Link to comment Share on other sites More sharing options...
Kartman01 Posted January 26, 2021 Author Share Posted January 26, 2021 6 minutes ago, Bill Stoneberg said: Is the firewall insulator still on the car ? It goes on the inside of the car up against the firewall. Thanks Bill, I will check. Link to comment Share on other sites More sharing options...
Matt Harwood Posted January 26, 2021 Share Posted January 26, 2021 Exhaust noise will be ticking like a bad lifter. Intake noise will be hissing or moaning. Can you describe the noise? Link to comment Share on other sites More sharing options...
Kartman01 Posted January 26, 2021 Author Share Posted January 26, 2021 8 minutes ago, Matt Harwood said: Exhaust noise will be ticking like a bad lifter. Intake noise will be hissing or moaning. Can you describe the noise? Hi Matt... it is definitely not a ticking noise like a lifter. To my ear, it sounds like the type of noise you would get from a leaking exhaust manifold gasket, but I know it can't be that. The exhaust manifold has been surfaced and a new exhaust manifold gasket installed. I can see no signs of any leakage anywhere. I hope that description helps. Thanks! Link to comment Share on other sites More sharing options...
Kartman01 Posted January 26, 2021 Author Share Posted January 26, 2021 24 minutes ago, Bill Stoneberg said: Is the firewall insulator still on the car ? It goes on the inside of the car up against the firewall. Bill, I can confirm the firewall insulator is still on the car and properly installed. Link to comment Share on other sites More sharing options...
Fr. Buick Posted January 27, 2021 Share Posted January 27, 2021 On the driver side manifold is the valve that passes exhaust gasses across the intake manifold. Mine, low miles at 68K or so was loose and caused an small noise. I tore it out and plugged the holes with tapered pins. Link to comment Share on other sites More sharing options...
Fr. Buick Posted January 27, 2021 Share Posted January 27, 2021 So maybe your valve? Link to comment Share on other sites More sharing options...
Bill Stoneberg Posted January 27, 2021 Share Posted January 27, 2021 Doug, are you talking about the flapper valve ? It was frozen when I got the car and in the process of rebuild it, it was welded open I believe. Link to comment Share on other sites More sharing options...
RivNut Posted January 27, 2021 Share Posted January 27, 2021 I'm not that famikiarvwith the I8 of a 50, but when the Buick engineers designed the next generation engine (nailhead) they designed it to be run with no exhaust manifold gaskets. As the manifold and head heat and cool, gaskets can be compressed but they don't un-compress leaving you with a leaky gasket. A straight eight guru can chime in here and let me know gasket or no gasket. Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted January 27, 2021 Share Posted January 27, 2021 11 hours ago, RivNut said: I'm not that famikiarvwith the I8 of a 50, but when the Buick engineers designed the next generation engine (nailhead) they designed it to be run with no exhaust manifold gaskets. As the manifold and head heat and cool, gaskets can be compressed but they don't un-compress leaving you with a leaky gasket. A straight eight guru can chime in here and let me know gasket or no gasket. Same! Worked well when new manifolds were available. Rem Flex gaskets seem to work now. Buy from Summit Racing. Cheaper than from Rem Flex. Ben 1 Link to comment Share on other sites More sharing options...
Bhigdog Posted January 28, 2021 Share Posted January 28, 2021 On 1/26/2021 at 11:35 AM, Kartman01 said: I am getting close to wrapping up addressing some of the issues I uncovered in my 1950 Buick Estate Wagon. One vexing problem I cannot seem to track down is an unusual amount of engine noise under acceleration. To my ears, it sounds more like exhaust noise than intake noise. I have checked the exhaust manifold, it is tight and square with no apparent leaks. The car has a very tight exhaust system and a proper OEM-style muffler. Are there areas on the firewall inside the passenger compartment that should have some kind of insulation? The floorboards have the correct jute padding and carpet, so no issues there. Are there any covers or insulating gaskets I sould look for that may be missing? I have not noticed anything, but I will admit that I don't know what is supposed to be there and what is not! Thanks in advnace for any help! Only under acceleration? Wondering if you are hearing pre-ignition or pinging. .......Bob Link to comment Share on other sites More sharing options...
Kartman01 Posted January 28, 2021 Author Share Posted January 28, 2021 13 minutes ago, Bhigdog said: Only under acceleration? Wondering if you are hearing pre-ignition or pinging. .......Bob Thanks Bob... it does not sound like pre-ignition... I decided to remove and replace the (new) exhaust manifold gasket to see if that improves things. Fingers crossed it does! Link to comment Share on other sites More sharing options...
Matt Harwood Posted January 28, 2021 Share Posted January 28, 2021 I'll vouch for the Remflex gaskets. Great product. Leak-free on my '41 Limited's headers and I'm having them make a full set of intake/exhaust gaskets for my '35 Lincoln V12, too. Much better than the usual stuff if you can't get the bare metal-to-metal seal to work (after all these years, it rarely does). Link to comment Share on other sites More sharing options...
Kartman01 Posted January 28, 2021 Author Share Posted January 28, 2021 I will definitely try the REM FLEX gaskets. Thanks for the recommendation! Link to comment Share on other sites More sharing options...
Bhigdog Posted January 28, 2021 Share Posted January 28, 2021 If it is an exhaust leak a length of rubber hose in an ear and used as a stethoscope will usually isolate the location.........Bob 1 Link to comment Share on other sites More sharing options...
Fr. Buick Posted January 30, 2021 Share Posted January 30, 2021 Have you checked for warpage on the exhaust manifold? I played with a friend's 50 Super once and wasted a few gaskets trying to get it quiet. I finally took the manifold to a machine shop and they showed me how badly it was warped, like a banana. You need a long milling table to get it done, but it's quiet again. Link to comment Share on other sites More sharing options...
364nailhead Posted January 30, 2021 Share Posted January 30, 2021 The wagon is 70 years old. Be glad. Link to comment Share on other sites More sharing options...
50jetback Posted January 31, 2021 Share Posted January 31, 2021 Are you sure it's not just your Air cleaner/Silencer? Under heavy acceleration my 1950 263 sounds like a 747 taking off. Well not quiet but you certainly hear that air being sucked in to get that motor going enough to spin the Dynaflow for lift off. Link to comment Share on other sites More sharing options...
Kartman01 Posted January 31, 2021 Author Share Posted January 31, 2021 7 hours ago, 50jetback said: Are you sure it's not just your Air cleaner/Silencer? Under heavy acceleration my 1950 263 sounds like a 747 taking off. Well not quiet but you certainly hear that air being sucked in to get that motor going enough to spin the Dynaflow for lift off. Thanks 50jetback; it is definitely exhaust noise. I was able to isolate an exhaust manifold leak using the rubber tube stethoscope method. I have taken the manifold to a machine shop for surfacing and have a set of REM FLEX gaskets on order. Hopefully all of that cures the problem. 1 Link to comment Share on other sites More sharing options...
Century Eight Posted April 4, 2021 Share Posted April 4, 2021 Have you considered one or more bad motor mounts? I was helping a friend wale up a 64 LeSabre a few years ago,(totally different) and it was making crazy noises, on acceleration. Exhaust was new, manifolds and everything tight, but the engine would move and pull the exhaust making a scrape sound as well as a leak noise under aggressive acceleration. Link to comment Share on other sites More sharing options...
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