Jarred767

Good to know!! It'll go to the top of the list once current issues are resolved haha

Oldblue

Don't let it go to long or it will be the issue!!

slonny

Slowly progressing... I drained the system and did a simple distilled water flush for 10 min with thermostat removed. For the second flush I decided to use Preston Flush + Clean mixed with distilled water and drive around for about a few hours before draining the system. On my way chech engine light came on.

The temperature gauge is not raising at all. Before removing the termostat the dial would be somewhere around the middle. Coolant display is showing ---- deg F. Is this normal?

RJ_RS_SS_350

Did you use ACDelco thermostat? Part #131-158. (GM #12622410)

Did you burp the system? There may be an air pocket.

Mods - Thermostat is not in the common part number thread.

donbrew

If you drive without a t-stat you WILL get a code P0128 and the gauge will go flat line. Too cool.

slonny

Just got a scanner and it shows P0128: coolant thermostat ( coolant temperature below thermostat regulating temperature.)

donbrew

The lecture one more time.

The T-stats job is to keep the temperature UP above 180F. NOT keeping the coolant cool.

The radiator and fan job is to keep the temp below 220F

slonny

No, I got ACDelco 12T103D GM# 19137281. It had good reviews and was a little less expensive than the other one. Anyone had problems with this particular one?

The thermostat that I took out shows no signs of wear at all. The rubber seal is in very good condition.

whopper

I'm out of this one. Its just too painful. Sorry.

RJ_RS_SS_350

OK, well that used to be the right one. That is the old version. It's believed that the new part is of an improved design. I would think that the one you installed should work, tho

You should elevate the front of the vehicle at least 8" above level. Get the filler neck so that it's the highest part of the cooling system. Run the engine, carefully monitoring the coolant level at the filler neck, keeping it full. Squeeze all the hoses, trying to work any air pockets out.

It may take several attempts, even a few days.