I noticed peach colored discoloration on the exhaust manifold near where it goes to the turbo. 2021 model with 170 hours. Is this normal?
M4-071 Exhaust manifold discoloration
- Thread starter FlyingDonkey
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North Idaho Wolfman
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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Yea normal, run it hard at night and get it into a dark location and the Exhaust manifold will be glowing red!
I agree with Wolfman completely normal. On a side note, had a turbocharger Malibu with a catalytic convertor failure (plugged) cold engine start within 3 minutes of running turbo and exhaust manifold glowing red hot(no night needed) and would only rev to about 1500 RPM's(tried this a couple times as owner stated it only been like this for a couple weeks). 
Agreed this is normal as the iron "seasons" (for lack of a better term) and gets the surface it'll have for life.
Years ago my workplace had an (undersized of course) machine working on a customer's site.
Foreman calls in a panic:
"It's overheating, it's running way too hot!"
"Why do you say that?"
"The exhaust manifold is glowing red and there's a flame out the stack!"
"Let 'er roar."
"What??"
"This is normal for something you're pushing hard. Plus it has temp sensors that'll shut it down if something indeed gets too hot."
Machine survived the job. Came back and the exhaust had that nice light-grey inside from a good old fashioned "cleaning out".
Aside story:
Years ago my workplace had an (undersized of course) machine working on a customer's site.
Foreman calls in a panic:
"It's overheating, it's running way too hot!"
"Why do you say that?"
"The exhaust manifold is glowing red and there's a flame out the stack!"
"Let 'er roar."
"What??"
"This is normal for something you're pushing hard. Plus it has temp sensors that'll shut it down if something indeed gets too hot."
Machine survived the job. Came back and the exhaust had that nice light-grey inside from a good old fashioned "cleaning out".
Back in the mid 70s, on a trip to California while climbing a grade on I40 in New Mexico one night, a UPS truck, one of the day cab GMCs with the engine sticking out of the back of the cab, passed me and the turbo housing, exhaust manifold and a couple of feet of exhaust pipe were glowing red hot. Hadn't seen that before.