2016 Sierra 5.3 Coolant Issue

[acc412]

 

Good Morning:

 

About 5 months ago I noticed that my thermostat was not hitting 210 like it normally does under normal driving conditions. I popped the hood and noticed that the coolant reservoir  was in the middle so i added coolant.

 

Since then I've noticed that on normal driving it always hovers under 210 and doesn't hit 210 until I step on it.

 

Any ideas?

 

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[diyer2]

You are worrying about something that isn't worth the time.

 

[Jsdirt]

Worn out t-stat. Happens in all of them eventually. I've got a lazy one in mine. It'll fail completely soon. When my truck was new, it used to have the engine fully warm in less than 2 miles. Now 13 years and 101k miles later, it takes over 6 miles. If it gets bad enough, it will throw the money light on.

 

Unless you're not getting sufficient heat in the cab when you want it, I wouldn't worry about it too much. A cooler running engine is a longer lasting engine.

[Doug_Scott]

It is well within the normal range.  You are also looking at the factory gauge, which is rarely 100% accurate.  The coolant recovery tank should have two lines, one for cold, and one for hot.  It is normal for the coolant level to change depending on engine temperature.  Filling a cold tank to the hot line will only result in a coolant leak once the engine gets hot.

You will also find the engine temp will change with air conditioning usage.  And not necessarily be hotter like you would expect.  The a/c turns the fans on to put through the condenser, and therefore also through the radiator.

[acc412]

Thanks for the replies. I see what you are saying about it being a lazy thermostat. Since the truck has 64,****** on it i was going to replace it this weekend with an OEM thermostat housing. Just to air on the side of caution. 

 

Going to be hitting the beach soon and driving on it so i want to make sure my cooling system is OK as it gets 100+ where I am on the sand. 

 

Plus its a $30.00 part plus my time so why not. Its easy to change out from what i've seen

Edited June 16, 2020 by acc412

[acc412]

1 hour ago, Jsdirt said:

Worn out t-stat. Happens in all of them eventually. I've got a lazy one in mine. It'll fail completely soon. When my truck was new, it used to have the engine fully warm in less than 2 miles. Now 13 years and 101k miles later, it takes over 6 miles. If it gets bad enough, it will throw the money light on.

 

Unless you're not getting sufficient heat in the cab when you want it, I wouldn't worry about it too much. A cooler running engine is a longer lasting engine.

Funny you say this. In the winter 73 used to be hot enough for me. I had to crank it to 77 to get hot.