Exhaust Manifolds smoking

dynamic88 · 06-01-2007, 04:35 PM

need help. Have problem with what appears to be smoke coming from the exhaust manifolds on 65 olds dynamic 88 v8 425 motor. I took them off and put gaskets on them. there were none there. starts off not smoking, but after about 5 minutes its smoking very heavy. It has a nasty eye burning smell to it. It looks as if it is smoking just pours right off the manifolds themselves. Im not sure whats causing it. The car has sat in barn for 20 years. I got it running last summer. any suggestions, i'm all ears. thanks chris. also noticed inside the pipe part of the left manifold there is a round flapper with a round coil on the outside of the manifold. what is that.

joe_padavano · 06-02-2007, 12:07 PM

Quote:

Originally Posted by dynamic88

need help. Have problem with what appears to be smoke coming from the exhaust manifolds on 65 olds dynamic 88 v8 425 motor. I took them off and put gaskets on them. there were none there. starts off not smoking, but after about 5 minutes its smoking very heavy. It has a nasty eye burning smell to it. It looks as if it is smoking just pours right off the manifolds themselves. Im not sure whats causing it. The car has sat in barn for 20 years. I got it running last summer. any suggestions, i'm all ears. thanks chris. also noticed inside the pipe part of the left manifold there is a round flapper with a round coil on the outside of the manifold. what is that.

First, Olds did not use gaskets on the exhaust manifolds, which is why there were none there. You don't need them.

Second, the smoke is almost certainly oil leaking from the valve cover gaskets. You may want to replace those.

dynamic88 · 06-02-2007, 05:54 PM

i found that out today and ordered some valve cover gaskets. will it hurt if the manifold gaskets are there. it was a real pain trying to bolt the exhaust all back up. thanks chris

joe_padavano · 06-02-2007, 07:14 PM

The exhaust gaskets will not harm anything, just not needed. The flapper and coil on the driver's side manifold is the heat riser valve. The coil is a bimetallic spring and expands as it heats up. When cold, the spring closes the flapper and directs the exhaust through the crossover under the carb and out the other manifold. Once the engine warms up, the spring expands and opens the flapper. This valve often rusts in place, so at a minimim be sure it opens (or is rusted in the open position).

dynamic88 · 06-03-2007, 05:45 AM

okay thanks for the help

dynamic88 · 06-03-2007, 01:00 PM

joe, is there a way to test the heat riser valve without taking the manifold back off. if i remember right when i had the manifold off. the valve was sitting sideways in the manifold. the outside coil is pretty rusty so i dont know if its working properly or not. i would imagine you can replace those but im not sure or if its even that big of a deal. let me know when you have time thanks chris

06-01-2007, 04:35 PM	#1 (permalink)
dynamic88 Senior Member Join Date: Oct 2006 Posts: 147	Exhaust Manifolds smoking need help. Have problem with what appears to be smoke coming from the exhaust manifolds on 65 olds dynamic 88 v8 425 motor. I took them off and put gaskets on them. there were none there. starts off not smoking, but after about 5 minutes its smoking very heavy. It has a nasty eye burning smell to it. It looks as if it is smoking just pours right off the manifolds themselves. Im not sure whats causing it. The car has sat in barn for 20 years. I got it running last summer. any suggestions, i'm all ears. thanks chris. also noticed inside the pipe part of the left manifold there is a round flapper with a round coil on the outside of the manifold. what is that.

06-02-2007, 07:14 PM	#4 (permalink)
joe_padavano Moderator Join Date: Mar 2007 Location: Northern VA Posts: 1,456	The exhaust gaskets will not harm anything, just not needed. The flapper and coil on the driver's side manifold is the heat riser valve. The coil is a bimetallic spring and expands as it heats up. When cold, the spring closes the flapper and directs the exhaust through the crossover under the carb and out the other manifold. Once the engine warms up, the spring expands and opens the flapper. This valve often rusts in place, so at a minimim be sure it opens (or is rusted in the open position). __________________ Joe Padavano 64 Jetstar 88 Conv 66 442 L-69 Conv 68 W-30 69 H/O 69 442 70 W-30 72 442 84 Custom Cruiser 86 Caprice wagon (w/307 Olds)

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06-02-2007, 05:54 PM	#3 (permalink)
dynamic88 Senior Member Join Date: Oct 2006 Posts: 147	i found that out today and ordered some valve cover gaskets. will it hurt if the manifold gaskets are there. it was a real pain trying to bolt the exhaust all back up. thanks chris

06-03-2007, 05:45 AM	#5 (permalink)
dynamic88 Senior Member Join Date: Oct 2006 Posts: 147	okay thanks for the help

06-03-2007, 01:00 PM	#6 (permalink)
dynamic88 Senior Member Join Date: Oct 2006 Posts: 147	joe, is there a way to test the heat riser valve without taking the manifold back off. if i remember right when i had the manifold off. the valve was sitting sideways in the manifold. the outside coil is pretty rusty so i dont know if its working properly or not. i would imagine you can replace those but im not sure or if its even that big of a deal. let me know when you have time thanks chris