changing oil on GM 8.1L with oil cooler

[1 FMF]

picked up a 2006 gmc 2500hd with the 8.1L.
It has an oil cooler and one of the lines from the block to oil cooler is seeping oil at the factory crimp. I am probably going to replace the lines with stainless braided AN hose and a new cooler.
but my question is, when i do an oil change does the oil drain down from the oil cooler which is mounted up in front of the radiator? And when i start the engine how long do you think it will take for oil to travel up and back from the oil cooler? This will be relevant when i get around to replacing the oil cooler lines and the cooler. I'm worried about lack of oil to crank during start up.

the lubrication path as listed in my service manual is this:
- oil from pan into oil pump
- from pump to oil filter outlet in engine block
- thru oil filter back into engine block
- out to oil cooler through outlet port in block right next to oil filter
- thru oil cooler at radiator and back to cooler inlet right next to outlet at oil filter
- now oil goes to crankshaft main bearings and up to lifter gallery, oil pressure sender, and cam bearings.

 

[oggb]

Pull the fuse for the fuel pump and crank it for a while with the throttle plate wide open. I think if you hold the throttle wide open it won't feed fuel anyhow on GM vehicles, but better safe than sorry.

Oughta be enough for those lines and such to fill back up with oil.

 

[yonyon]

Pulling the fuse for the fuel pump and cranking it won't work if you do that after changing the oil/filter because there'll already be enough fuel pressure to fire it up. I'f you want to go the kill the pump route, kill the pump and run it until it stalls before draining the oil.

Alternatively, for a similar effect, you could put the key in your back pocket (no injector pulswe and no spark) and jumper the starter. This also gives you the benefit of not worrying about turning the check engine light on.

 

[Chris142]

It will only take milliseconds for the oil to flow to the cooler. Change your line and dont worry about the rest.

 

[The_Eric]

Originally Posted By: Chris142
It will only take milliseconds for the oil to flow to the cooler. Change your line and dont worry about the rest.


This.

 

[c502cid]

Originally Posted By: Chris142
It will only take milliseconds for the oil to flow to the cooler. Change your line and dont worry about the rest.


Good advice here. Did the cooler line change on my old 2003 8.1, oil pressure comes up before you can look at the gauge.

 

[GMBoy]

The guys are right - don't worry about the oil - it will pressurize and fill the system in less than a few seconds.

Those cooler lines do leak alot at the crimp. I wouldn't bother replaceing the lines and cooler...jusy replace the leaking line. The new style lines are improved and your new oil cooler won't be any more effective than the factory one. Save your money and time - just replace the line.

(You know you can always PM me for the part #'s - LOL!)

 

[1 FMF]

when i was initially looking at things, I mistook the power steering cooler on the front of the radiator for the oil cooler. I still have to double check, but it looks like the oil cooler is integrated with the radiator, and with the fitting on the radiator I will most likely just get new GM oil lines
thanks for the help.

just received new stepper motors and lights for the IPC, expecting saturday bilstein HD shocks along with intermediate steering shaft. so it will most likely snow.

 

[1 FMF]

Originally Posted By: GMBoy


Those cooler lines do leak alot at the crimp. I wouldn't bother replaceing the lines and cooler...jusy replace the leaking line. The new style lines are improved and your new oil cooler won't be any more effective than the factory one.


cool to hear there the oil cooler lines are updated.
would you be able to confirm the ones on rockauto are updated?
they are acdelco 15809063 for outlet and 15809062 for inlet. thanks.