Anyone from GM (LGZ engine oil bypass/thermostat question)

Fifty

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Anyone here from GM that would know if the 2018 colorado v6, the LGZ, has a thermostat bypass built into the part where the oil cooler lines leave and enter the block?

it may be in the oil filter bracket.
 

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jon coleman

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i would say yes, with todays oil tech& mpg rules& targets, top eng . performance is paramount!!, but could be wrong Fifty( imagine that...😱
 

Fifty

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Ha! I want to agree with you. Especially with the desire for everything to be so hot for epa ratings.
Ect thermostat cracking at 194 but not fully open into 212 and the fans don’t even start turning until 221°... and get to 50% speed at 228°
Trans has a thermostat but I think it’s a 175-180° I can’t confirm it. I’m still trying to find out. I’ve heard it’s as high as 210°...
 

Fifty

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Looks like no thermostat...
exit from the top port in the filter housing, and return line is below the housing into the block.

so no thermostat bypass.

Im going to be running a single pass top entry bottom exit oil cooler in the bed.
So it’s going to be higher than the oil Pan even if it is 12 feet or so away.

I need to figure out how to stop the oil in the cooler from emptying and overfilling the pan when the motor is turned off.

any ideas?
 

Fifty

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im supercharging the truck and the heat exchanger for the s/c has to go where I had a regular plate oil cooler.

I purchased a pair of cbr0052 coolers (with twin fans) for an engine oil and trans oil; to put in the bed rack.

the engine does not have a thermostat in the oil system, so my plan is to put a 200° thermostat bypass in the lines that go to the cooler in the bed.

but for the trigger for the fan, the hottest one I could find was a 200° on 190° off (I think or maybe it was 205 on) Most of the fan triggers are 170,180 or 190°...

that seems low, i feel like the fans shouldn’t come on until 225° Oil temp. The factory engine coolant targets are 214-225° as its a 2018 Chevy Colorado v6.

Am I not thinking clearly? Should I be running a cooler fan trigger? Should I be running a cooler thermostat bypass?

should I go for a lower bypass thermostat temp to send oil to the cooler at a lower temp? And/or have the fans turn on cooler?

I can not find any target oil temp data for the engine which sucks... but I’m sure it’s identical to any of the 2015 and newer 5.3l and 6.2l V8 as they share so much design focus.
 

jon coleman

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had same question years ago, depends Where you measure temp, inlet or outlet of cooler, 200 is probably right on Outlet, means oil going In is Much hotter than 200, and 200 oil temp going into a 225 temp motor shouldn't be a problem, DONT QUOTE ME ON THIS😵my temp switch was for water, 190 , out of radiator, probably goes in at 210 -20
 

Fifty

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Yea. Thermostat bypass is coming out of filter housing.

fan switch would be just before the cooler in the bed.

the return line enters the block, just above the pan.

on one hand 200 seems low. Where the bypass just opened and the fan turns on immediately... and then the bypass turns off and fan turns off....
Then repeat...

I want the oil to be 210-220 in the engine as that’s 10-30w target temp for efficiency etc...

..but then I don’t want it to be mistakingly high where it gets out of control because it’s too late.
 

partybarge_pilot

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Put the temp sensor farther down stream. If you have a 200* right before it goes back in that should keep it there a lot better than having it before the cooler.

I have gotten switches higher than 200*, I'll see if I can remember where.
 

Fifty

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Ok. I think I understand....

let me preface with: I have been getting a few places (smart people) tell me to run a 165° fan switch.

I haven’t gotten any word on a suggested thermostat bypass temperature.

anyways. My plan for plumbing is as follows:

Exit the factory oil filter bracket, to a thermostat bypass, then to a one way check valve, then to bed, through a 165° temp fan trigger, into the bottom of a single pass cooler, exit the top of the cooler, back to the thermostat bypass and then enter the block in the factory return port.


the plumbing is going to be soft braid wrapped in a heat shield when it exits the engine, then when it exits the thermostat bypass it will use aluminum hardline. Then soft line, to a bulkhead fitting at the bed, then soft line to the cooler. (Then reverse)

I was originally going to do a 200° thermostat bypass, but I have a feeling I’m going to be going down to the 165° temp...

Ok as to your point to fan therm switch location? Are you saying mount it after the cooler... near the thermostat bypass? Or anywhere after the cooler?

for some reason I had it in my mind to mount before the cooler. No idea why really...
 

Fifty

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Went with a 185° thermostat bypass and a 185° on and 165° Off fan switch
 

Fifty

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Thank God this wasn’t some crazy bespoke thread! An off the shelf fitting will work for the output and return for the oil cooler!!

714475A7-7154-436A-B7FD-432AC4635746.jpeg
 
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