Guage Readings

REKIII · August 19, 2005

I have an 01 8.1 with the allison (4X4) and just curious about the normal operating temps and pressures.

The oil pressure is especially concerning as it seems to vary between 20 to 60+ depending on load.

Thanks in advance!

Bob

knez · August 20, 2005

Well Bob my 04 8.1 cc 22k is right there to cold at about 55 to 60.Warm idling 20-30 normal freeway driving i think around 40.Trans temp never seen it over 185 (stop n go traffic) and cruising freeway depending on weather 130-155.Hope this makes ya feel better.Oh and engine once warm 205 allways.

8.1L · August 20, 2005

I have an 01 8.1 with the allison (4X4) and just curious about the normal operating temps and pressures.

The oil pressure is especially concerning as it seems to vary between 20 to 60+ depending on load.

Thanks in advance!

Bob

<{POST_SNAPBACK}>

I'm right there with knez and his readings. My 8.1 is in a 2005 Yukon XL, and the warm idling oil pressure drops to like 20, and warm driving op is 40-42. My tranny temps track with his, as well, but the 'burbans don't come with the Allys, of course.

Hope this helps...

REKIII · August 22, 2005

Yes that help.

Temps from mine correlate (going 90 through the rockies got them both up to 200 but I wont talk about that)

My oil pressure seems to be around 60 all the time though. Except when idleing warm. I was wondering if that is what caused my mysterious drip by the transmission.

Whenever I park the truck puts one drip of oil down. The pan and the starter motor is wet. I didn't know if maybe the increased oil pressure was starting to blow out the rear main or what. Frustrating in any case.

Thanks for the info.

Bob

zippy · August 22, 2005

Yes that help.

Temps from mine correlate (going 90 through the rockies got them both up to 200 but I wont talk about that)

My oil pressure seems to be around 60 all the time though. Except when idleing warm. I was wondering if that is what caused my mysterious drip by the transmission.

Whenever I park the truck puts one drip of oil down. The pan and the starter motor is wet. I didn't know if maybe the increased oil pressure was starting to blow out the rear main or what. Frustrating in any case.

Thanks for the info.

Bob

<{POST_SNAPBACK}>

i'd recomend checking the back of the intake for an oil leak.

Trouttrooper · August 23, 2005

I guess that makes me feel better about my oil pressure since it does the same thing.

Is it just a big block thing to vary the oil pressure? I've always had small blocks and they seem to always hold a constant pressure no matter what.

REKIII · August 23, 2005

My moms S10 does the wild oil pressure thing too but she has the crappy cavilier motor so I just thought it was cause the motor sucked.

Check the intake? Like the breather? I'll do that, is there something that wears out, or is there a possibility of major blow by? That would suck.

Bob

Supercop8100 · September 1, 2005

The reason the oil pressure in late model big block engines fluctuate so much is because of the enlarged oil passages. Small blocks are made with smaller passages, especially around the oil pump, for a more steady pressure regulation. Its regulating the oil pressure without the addition of a mechanical pressure regulator. The big blocks do not have these "plugs" to help mandate oil pressure. The general thought it to be better to just let the engines get "oil in demand" due to mostly extreme heavy duty uses.