Engine/Transmission (1994 - 1998) Exhaust manifold

[RHoblitt]

I want to drill and tap my exhaust manifold on my 98 12valve for a EGT probe and i know the 24 valve manifolds have a center web so you have to drill off center but not sure about the 12 valve manifolds. Does anyone know if 12v have the center web or not, and where is the best location for the probe. Thanks Richard

 

[vssman]

I believe 12V's have a center web too. I drilled mine about 5/8" off the center toward the firewall and just at the point where the hole would still be on the flat before the curved section that goes to the turbo mounting flange.

 

[Dkevdog]

Pyrometer Probe and gauge mounting instructions here .



Kev

 

[illflem]

Seems like all the pyro install instructions I've seen always show tapping the rear section on the manifold but the front section is supposed to run hotter. Flip a coin.

 

[DSutton]

Yes, the 12V manifold requires you to drill off center. Just did mine 2 weeks ago.

 

[bowhunter]

Tap the front section. There is a small difference in the temp's like illflem mentioned.

 

[Tardog]

illflem



Why would the front run hotter? I thought it would be the opposite. Closer to cooler fluids and air? Please enlighten me (us)Thanks