Exhaust Manifold gets RED HOT!!!

[Texan4ever]

My exhaust manifold on my 1986 Gmc Vandura 3500 motorhome is getting to hot it only happens on one side and that side has a valve of some sort between the exhaust manifold and where the tail pipe bolt together. No one around here seems to know what the part is called so I can replace it. Do you think I can just remove it? The vehicle does not have to pass emmissions anymore, just safety inspection. This engine also has chrome looking risers that have black boxes that connect to a air pump. Could this also cause the problem and be removed?

[MagicRat]

This is the passenger side manifold, right?

I think you mean the heat riser valve. This valve can be removed. Ideally it helps a bit with cold weather starts and faster warm up, but they often malfunction and get stuck closed which costs you power and fuel economy.

I have wired the valve open on my GMC 2500 van with good performance results, yet it still runs fine in the coldest Canadian winter.

As for the hot manifold.........this valve should not cause that. I think you may have a burned or leaking exhaust valve or two on one side, or poor combustion due to bad wires, plugs etc on that side.

[454Chevy]

My friend has a 1986 suburban and hade the same problem with the manifold
he put some headers and the fixed the problem he get better gas milege now

[454Chevy]

Originally Posted by MagicRat

This is the passenger side manifold, right?

I think you mean the heat riser valve. This valve can be removed. Ideally it helps a bit with cold weather starts and faster warm up, but they often malfunction and get stuck closed which costs you power and fuel economy.

I have wired the valve open on my GMC 2500 van with good performance results, yet it still runs fine in the coldest Canadian winter.

As for the hot manifold.........this valve should not cause that. I think you may have a burned or leaking exhaust valve or two on one side, or poor combustion due to bad wires, plugs etc on that side.

it does turn red hot it happens dependding on how long you run it