So, tackled a 2020 Colorado with 26,500 miles and the 3.6 V6 engine. Recently had a 2018 Suburban, landlords, doing the same thing as this Colorado. Temp gauge stuck at 160 degrees, CEL codes P0118 and P0128, having to do with the thermostat and the Coolant Temp Sensor. The cooling fans were staying on for 10 minutes after shut engine off, too.
They did not want to pay for the upper intake labor, for CTS access, so I was just gonna do the thermostat and cross fingers. When you look at you tube, most say the upper intake does have to come off for the CTS. One guy even made a special tool and wants $90/shipped for it. I looked at the videos and came up with an idea. I used a 15mm 12 point ICON long beam tool that has more than a 90 degree flex at the end and is a combo 15mm and 13mm and about 20" long.
Just to let you know, the CTS is tilted slightly toward the valve cover/away from center. I removed the thermostat housing/thermostat combo, that is a feat all of it's own because the 2 10mm bolt heads are hidden a bit but a 1/4" wobble extension worked for me. Do not leave the attaching bolts in there. I removed with mechanical fingers. Snaked the housing out thru the front hole and that is a bit tricky too.
Broke the CTS loose and then the fun starts. There is no "throw room" so I kept ratcheting it but had to reach in with my middle finger, no room for any more than one finger when tool is on the CTS. I had to ratchet loose and ratchet tighten and then hold pressure with the one finger to grab a couple teeth for removal and install. Basically have to have eyes in your fingers. Got it all back together, filled with coolant.
Did an oil and filter change. Cabin Air Filter and engine air filter and cleaned the MAF sensor. Reset oil change reminder and put a w/s sticker on it. Inspected the throttle body and was ok for now. Cleared codes and took on a long road test and topped off the coolant when returned.
By the way, first I drained coolant at radiator so when I released the upper hose housing, I would not have coolant all over the belt. I refilled system with fresh 50/50 Dexcool mix. After all that prep for coolant flow, I still had some come out of a small coolant pipe when I pulled the small hose, in the pics, for access.
The thermostat and CTS took close to 2 hours time. Complete time going in and back out and running.
They did not want to pay for the upper intake labor, for CTS access, so I was just gonna do the thermostat and cross fingers. When you look at you tube, most say the upper intake does have to come off for the CTS. One guy even made a special tool and wants $90/shipped for it. I looked at the videos and came up with an idea. I used a 15mm 12 point ICON long beam tool that has more than a 90 degree flex at the end and is a combo 15mm and 13mm and about 20" long.
Just to let you know, the CTS is tilted slightly toward the valve cover/away from center. I removed the thermostat housing/thermostat combo, that is a feat all of it's own because the 2 10mm bolt heads are hidden a bit but a 1/4" wobble extension worked for me. Do not leave the attaching bolts in there. I removed with mechanical fingers. Snaked the housing out thru the front hole and that is a bit tricky too.
Broke the CTS loose and then the fun starts. There is no "throw room" so I kept ratcheting it but had to reach in with my middle finger, no room for any more than one finger when tool is on the CTS. I had to ratchet loose and ratchet tighten and then hold pressure with the one finger to grab a couple teeth for removal and install. Basically have to have eyes in your fingers. Got it all back together, filled with coolant.
Did an oil and filter change. Cabin Air Filter and engine air filter and cleaned the MAF sensor. Reset oil change reminder and put a w/s sticker on it. Inspected the throttle body and was ok for now. Cleared codes and took on a long road test and topped off the coolant when returned.
By the way, first I drained coolant at radiator so when I released the upper hose housing, I would not have coolant all over the belt. I refilled system with fresh 50/50 Dexcool mix. After all that prep for coolant flow, I still had some come out of a small coolant pipe when I pulled the small hose, in the pics, for access.
The thermostat and CTS took close to 2 hours time. Complete time going in and back out and running.
