[Bob]

Just yesterday, I had a recently retired Detroit Diesel/Allison Trans mechanic tell me two minutes on low idle, then up to high idle. He said don’t start the engine on high idle. This was for a Series 60.

[Bob]

I recently researched and confirmed the same as Dick. Regular idle two minutes prior to engaging high idle.

[Chuck & Katrina]

Why?

I do not disagree, but would hope for a logical reason. I’m sure it has to do with being certain oil has built pressure and has lubricated all the parts, but it doesn’t take two minutes for that to happen.

There are those on here who observe that delay to insure air pressures have inflated the belt tensioners so when going to high idle the belts are tight.

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2000 Featherlite H3-45

2024 Jeep Grand Cherokee

Leesburg, FL

[Chuck]

Thanks for all the replies, I have been doing it right.

[Jeff]

Low idle upon starting, then wait just long enough to take any slack out of belts that might have occurred due to low air pressure. This is a reason to delay not oil pressure.