Sheener Posted May 5, 2022 Share Posted May 5, 2022 Finally determined that the wet on my plugs was oil. Pulled the intake and found a leak between the intake manifold and the lifter valley. I will get that sealed up. On the back of the engine block is another port that I had not noticed until I pulled the intake. It has a control on it and the line is vented to atmosphere right now. What is it for and how should it be vented? Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 6, 2022 Share Posted May 6, 2022 I'm glad you found the oil problem. That could certainly cause both fouled plugs but also a very lean air/fuel mix. But I don't know what "port" you are asking about. You don't have what engine you have in a signature, so I can't tell. But the 460's and M-blocks have an oil pressure port back there, and there is usually an oil pressure sender on it. But there wouldn't be a "line vented to the atmosphere" or you'd have a huge mess. Link to comment Share on other sites More sharing options...
Sheener Posted May 6, 2022 Author Share Posted May 6, 2022 I'm glad you found the oil problem. That could certainly cause both fouled plugs but also a very lean air/fuel mix. But I don't know what "port" you are asking about. You don't have what engine you have in a signature, so I can't tell. But the 460's and M-blocks have an oil pressure port back there, and there is usually an oil pressure sender on it. But there wouldn't be a "line vented to the atmosphere" or you'd have a huge mess. Link to comment Share on other sites More sharing options...
Sheener Posted May 6, 2022 Author Share Posted May 6, 2022 I'm glad you found the oil problem. That could certainly cause both fouled plugs but also a very lean air/fuel mix. But I don't know what "port" you are asking about. You don't have what engine you have in a signature, so I can't tell. But the 460's and M-blocks have an oil pressure port back there, and there is usually an oil pressure sender on it. But there wouldn't be a "line vented to the atmosphere" or you'd have a huge mess. This is what I am talking about. Is that the sending unit? Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 6, 2022 Share Posted May 6, 2022 This is what I am talking about. Is that the sending unit? That is the thermactor plumbing. The air pump pushes air through that valve in the center and into the heads via the tubing on either side that bolts to the back of the heads. Looks like someone disconnected the air pump but left the plumbing. The plumbing can be removed and very short 5/8-11 bolts threaded into the back of the heads to plug the ports. But you may have to clean carbon out of the threads to get the bolts started. And I like to use copper gasket washers under the heads of the bolts. Link to comment Share on other sites More sharing options...
Sheener Posted May 6, 2022 Author Share Posted May 6, 2022 That is the thermactor plumbing. The air pump pushes air through that valve in the center and into the heads via the tubing on either side that bolts to the back of the heads. Looks like someone disconnected the air pump but left the plumbing. The plumbing can be removed and very short 5/8-11 bolts threaded into the back of the heads to plug the ports. But you may have to clean carbon out of the threads to get the bolts started. And I like to use copper gasket washers under the heads of the bolts. That valve in the center is not connected to the thermactor plumbing. To the left is where the valve connects to the thermactor. Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 6, 2022 Share Posted May 6, 2022 That valve in the center is not connected to the thermactor plumbing. To the left is where the valve connects to the thermactor. Then you either have a 460 or an M-block and that's the oil pressure sender/switch. Link to comment Share on other sites More sharing options...
Sheener Posted May 6, 2022 Author Share Posted May 6, 2022 That is the thermactor plumbing. The air pump pushes air through that valve in the center and into the heads via the tubing on either side that bolts to the back of the heads. Looks like someone disconnected the air pump but left the plumbing. The plumbing can be removed and very short 5/8-11 bolts threaded into the back of the heads to plug the ports. But you may have to clean carbon out of the threads to get the bolts started. And I like to use copper gasket washers under the heads of the bolts. That valve in the center is not connected to the thermactor plumbing. To the left is where the valve connects to the thermactor. Link to comment Share on other sites More sharing options...
85lebaront2 Posted May 6, 2022 Share Posted May 6, 2022 That valve in the center is not connected to the thermactor plumbing. To the left is where the valve connects to the thermactor. It would really help if you could put some details as to what your truck is, engine etc. Then we could give you better informed answers. Link to comment Share on other sites More sharing options...
mat in tn Posted May 6, 2022 Share Posted May 6, 2022 It would really help if you could put some details as to what your truck is, engine etc. Then we could give you better informed answers. it is the oil pressure sending unit and it is unplugged Link to comment Share on other sites More sharing options...
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