I was just about to take my exhaust manifold to weld bungs for pre-turbo EGT sensors before tuning. I got the turbo off (I have single) and noticed that the manifold already has bungs welded on it. They look like small pieces of pipe welded on, and have threads on the inside (i'm guessing 1/8 NPT).

I was expecting these to actually be blocked off and have an open whole inside to get exhaust gas (Like an O2 sensor). BUT, they do not actually open into the manifold, I hooked a hose to one and blew, and its sealed. Am I just stupid and EGT sensors don't need to actually test the exhaust gas itself and being welded to the steel manifold is good enough? It was obviously used as is before, but I just figured the EGT sensors would be in the gas stream like an O2 sensor.

What do you think?

 

its the greddy T78 steel manifold

 

pic?? sounds more like a mounting point for some type of heat shielding or something. most egts are in the exhaust flow.

z

 

The EGT probe does need to be in the exhaust stream. As suggested, the hole is probably tapped for a screw.

 

If you can verify that it is in fact 1/8th inch NPT threads, then you can CAREFULLY drill a hole through the center to mount an EGT sensor in those bungs.

 

my PC is crapping out making it hard to get pics on line. since I have the turbo off I'll take off the manifold. The comment about possibly being for a heat shield makes a lot of sense. I have not verified that they are actually NPT. I think i'll just leave them alone and put some real bungs on. Is there a good place to purchase 1/8th NPT bungs? I can't seam to find anything other than standard O2 sensor bungs locally.