need help ID-ing a part
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From: new jersey
need help ID-ing a part
here it goes!!!
on my 86 f150 w/ 351w
Between the firewall and engine, there is this 3/4" pipe with some sorta module screwed into it, This part sits right behind the right side valve cover. and the pipe goes from one side to the other side of the engine. at the top of this part there is a 3/4" round opening in it with a tiny fan in it, and it sounds like there is an exhaust leak coming from it. when I put my thumb over the hole exhaust leak sound goes away.
Can anyone tell what that part is, and its funtion to the exhaust system??? the chilton dont discribe the part.
Thanks Al
on my 86 f150 w/ 351w
Between the firewall and engine, there is this 3/4" pipe with some sorta module screwed into it, This part sits right behind the right side valve cover. and the pipe goes from one side to the other side of the engine. at the top of this part there is a 3/4" round opening in it with a tiny fan in it, and it sounds like there is an exhaust leak coming from it. when I put my thumb over the hole exhaust leak sound goes away.
Can anyone tell what that part is, and its funtion to the exhaust system??? the chilton dont discribe the part.
Thanks Al
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Joined: Dec 2001
Posts: 22,436
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From: Louisville,Ky.
Yep, That is where the smog pump pumped air into the heads. There should be a rubber hose going to it if the smog stuff is hooked up.
The piece that you are refering to is a one way valve that lets the air from the pump in, but is supposed to keep the exhause out. Your internal seal is leaking and the valve is bad. If you are not going to hook the smog pump back up, you can block it off to keep the exhaust in.
Jimmy
The piece that you are refering to is a one way valve that lets the air from the pump in, but is supposed to keep the exhause out. Your internal seal is leaking and the valve is bad. If you are not going to hook the smog pump back up, you can block it off to keep the exhaust in.
Jimmy
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From: new jersey
Thanks Jimmy
Yep, That is where the smog pump pumped air into the heads. There should be a rubber hose going to it if the smog stuff is hooked up.
The smog pump? is that the same as the thermactor system?
and if so, that has been disconnected for over a year now!
and never had a problem with it sounding like an exhaust leak, until a couple of days ago. I had my son bring the truck to his vo-tech school, to replace the transmission with a junk yard trany and when it came back, it had that exhaust leaking sound.
I wonder if they; At the school broke something off of that part where there should be a rubber hose?
You also mentioned in your post. Your internal seal is leaking and the valve is bad.
Is the valve like a check valve,and by blocking it, does that take care of the internal seal leaking???
And! How can I block it?
Thanks, Al
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Joined: Oct 2003
Posts: 480
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From: Elyria, Ohio
thermactor fitting
Not familiar with this exact configuration. Mine has 2 check valves; one in the side of each cylinder head. Probably does same thing. The check valves corrode internally from acids in exhaust and then don't keep the exhaust from escaping. It probably was corroded shut and then agitating it by working on the trans cause it to unblock port. Since you don't have the air pump; remove the fitting and plug the hole. If threaded it should be replaceable by a standard plumbing plug. If it has a hole with bolt retainer and no threads like mine then a small freeze plug is used.
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