Locating pyrometer

[Mark Rinker]

Installing pyrometer soon on 2006 K3500. Wondering where easiest access / best location for pyrometer probe is?

[madmatt]

Passenger side exhaust manifold. leave it running while drilling to keep metal out of your turbo.

[Mark Rinker]

Thanks...anywhere along the length of the manifold, or somewhere at the collector?

[madmatt]

I put it as close to the rear as possible and try to not line it up directly with an exhaust port but don't go out of my way to get it absoultly perfect. I've not noticed much difference anywhere in the manifold, those are really just quirks I have about pyro placements.

[Kennedy]

See my tech tips.

Also MP did a gauge install PR a while back.

[Mark Rinker]

Installed pyrometer probe. Has anyone else noticed a change in their normal engine sound after installation? My only other probe install experience was on a 6.5L and the engine rattle was loud enough it would have covered the sound I am hearing on the otherwise very quiet Duramax.

Only happens under acceleration, it comes and goes, and doesn't persist at cruise speed. If it were a gasser, you'd think it was a noisy lifter. The sound definately comes from the passenger side, and its not the sound of exhaust leaking at the threads, even used white hi-temp sealant and the threads were nice and tight.

Could the probe tip go harmonic at certain RPMs and pass a ticking type noise back through the cable? I zip tied it to an A/C line near the condensor on the way past - thinking of relocating it away from there.

Always sumpthin.

[Mark Rinker]

Sprayed the tapped area with oil soap while my son started the truck and brought it up to 1500rpm. No bubbles.

Same slight noise - during accleration only - persists. My theory is the probe 'flutters' slightly in its bung, and that harmonic is the noise that I'm hearing at certain RPMs. Its really no big deal, just odd.

Hey - at least I have my hearing...AND digital readouts of my egts...

[Inspector]

Mark:
Untie the therocouple lead from the AC line and take it up to the seam along the top of the firewall and slip it through the harness clips along that seam. Don't secure it tightly. See how that works. The thermocouple lead is braided and may be transferring the engine noise to the AC line and amping it up so you can hear it. Remember in the 6.2s and 5s the injector lines had to be cleared or you would swear that a lifter was clattering. Same thing could be happening here. No gaurentees though.
Denny