New thermostate and water pump, and coolant temp sensor. engine overheating

[rockola1971]

I've never had issues on these engines trapping air when replacing parts on them. They seem to self-bleed out the air by themselves.

The thermostat you can dunk in an old pot with boiling water and watch it open. It's a slow action, but you should see it.

Maybe you got a faulty water pump and it's not circulation the coolant? Not sure how you would test that?

I once had a heater core quick connect break on me and my truck almost got to the last red mark. Luckily, no blown head gaskets.

You can either get that kit that tests for combustion gases in the coolant or try that coolant pressure test kit to see if the system holds pressure, as further tests if nothing else works

The only "failure" ive ever seen on a mechanical water pump is seals leaking coolant out the front shaft or in the rear out the weep hole and one time on 2.8L V6 Firebird A1 Cardone was putting impellers on rebuilt water pumps that had vanes that faced the wrong direction and caused the coolant to just cavitate which caused the engine to overheat. That one was a blast to diagnose and then convince A1 Cardone(rebuilder) and the auto parts place that they were selling improperly rebuilt water pumps that would cause people's engines to overheat.

 

[S33k3r]

The only "failure" ive ever seen on a mechanical water pump is seals leaking coolant out the front shaft or in the rear out the weep hole and one time on 2.8L V6 Firebird A1 Cardone was putting impellers on rebuilt water pumps that had vanes that faced the wrong direction and caused the coolant to just cavitate which caused the engine to overheat. That one was a blast to diagnose and then convince A1 Cardone(rebuilder) and the auto parts place that they were selling improperly rebuilt water pumps that would cause people's engines to overheat.

How did you eventually prove that?

 

[rockola1971]

How did you eventually prove that?

Had to sit at the parts counter and pull out a haynes manual that showed belt route and belt diirection as the crank rotates then have them pull a water pump for the 2.8L V6 off the shelf and turn the water pump from the front the correct direction and have them watch the impeller rotation. You could tell by doing that, that the water would beat instead of push the coolant. The final nail was we pulled out a thick paper catalog of A1 Cardone that had all their water pumps pictures front and back in order by part number and low and behold the impeller vanes in the catalog faced the correct way. Every water pump they had on the shelf were wrong for the 2.8L at the auto parts store. I personally helped the auto parts store pull them off the shelf and open them up to inspect. Then the manager called up A1 while I was standing there and told them they had a big problem. Those water pumps were shipped out all across the U.S. by A1 Cardone. A1 never so much as gave me a thank you let alone a free water pump. Still wonder how many vehicles those idiots ruined because of them putting the wrong impellers on the pumps.
I took it a little more personal than someone that just bought a water pump because I bought a reman V6 and associated new install parts at the auto parts store and was fighting this overheat problem for a week after I installed the engine and knew it wasnt something I did or wrong with the car's radiator. Bought the car for $500 because the original engine had a rod knocking hard. This was all back in 1997 when I was stationed in northern Florida.

 

[Doubeleive]

all coolant was drained before installing any parts, filled after.
Hot AC running. (blows room temp)
both heater hoses are hot and hard to the touch.
both top and bottom radiator hoses are cool untill the engine reaches 240+ then they swell and feel hot to the touch.
checked radiator flow by filling coolant from the top hose and watching it come out the bottom hose.
coolant ressiviour is bubbling almost like its purging air.
over flows when it gets past 240 F.
thermostat is rated at 187f


not sure whats keeping the coolant from making a full cycle here. please help super confused this is a 2006 chevy tahoe 2wd ff 5.3

either the thermostat is stuck or inserted backwards or pump is not working or perhaps heater hoses routed backwards
1st clue is cool radiator hoses
heater hose with y goes on forward pipe, heater hose no y goes on rear pipe
2 clue is heater only blowing luke warm which means coolant is not cycling
thermostat should be tested, take it out and put it in some boiling water, see what happens
correct thermostat position shown below

 

[strutaeng]

Agree with @Doubeleive 100% I usually turn on the heater on after replacing a pump or coolant, to make sure there is heat inside the cabin. Usually that's an indication the coolant flow is good. So good observation again there.

Example: A few months ago I replaced the thermostat on my wife's 3.6 Pentastar minivan. I ran the engine and the heater wouldn't blow hot air at all. Waited like 30 minutes before I determined something was not right. I had to Google the issue: turns out there's a bleeder screw on thermostat (I think, maybe the pump?) that needs to be loosened to get the air out. Since this has to be done while the engine is running, air and coolant spills onto the accessories. It worked, but then the coolant made the belt squeal, so the following week I had to replace that. Doh!

 

[GRAYGEORGE]

Check to make sure you have the correct pump.