Went to install my Isspro thermocouple for my new EGT gauge and couldn't find a factory port anywhere on the exhaust manifold collector, inlet of the turbo or outlet of the turbo. Could it be that I simply don't have one and will have to drill and tap one?

My knowledge of exhaust gas temperature measurement is extensive in the gas turbine and aircraft recip engine area. But I've never installed, removed or did any troubleshooting on a diesel EGT system so not sure where the thermocouple is generally located. But my gut feel is that it should be located as close to the outlet/collector of the exhaust manifold as possible, is this right?

If installing a port in the exhaust manifold is prevented by a diffuser or requires removing it from the engine (and I think it would) is there another suitable option that provides an accurate EGT measurement?

While I'm in the area. Is turbo boost pressure measured at the outlet of the turbo or the inlet of the intake manifold? My C8.3 manual says that the pressure differential between the turbo outlet and the inlet of the intake manifold should not be more than 3 psid or you may have a restriction. But it doesn't identify where boost is measured. Any advice would be appreciated. Thanks in advance.

Roman

Boost is generally measured at the intake manifold.

I had the same issue with my 5.9L Cummins, I bought a new exhaust manifold because the old one had a lot of cracks and while out I thought it a good time to install a EGT probe. However, I didn't like the thickness of the manifold and to drill and tap the cast iron seemed to be an invitation to trouble. I removed the outlet plumbing from the turbo and welded a bung as close to the turbo outlet as possible. This will result in a lower temperature reading so that has to be taken into account. The general rule is to add 300 degrees to the EGT reading if it is taken after the turbo so I limit power when I hit 950 degrees. 1250 is considered the max for most Cummins when measured at the exhaust manifold outlet or the turbo inlet.

I measure the boost from a intake manifold source.

HTH

Thanks for the input guys.

After I got to thinking about my problem I did a google search to see if this issue has been addressed. It had, as a matter of fact Banks Performance has quite a good set of instructions for both EGT and Boost. As a result I went to the Cummins dealer and got gaskets, 4 new studs and nuts for the turbo flange mounting. Also, picked up the instructions for testing the waste gate operation.

I'm not looking forward to removing the turbo and drilling and tapping the exhaust manifold but it has to be done to monitor EGT upstream of the turbo. Thanks again.

Roman

is the pacbrak to far from the turbo. the pacbrake has a 1/8npt for checking brake pressure and that is 35#or65# because of valve spring being upgraded
lenny