2005 Chevy Suburban Coolant Issue

[shultzee13]

I have a new to me 2005 chevy suburban LT 5.3L

I cant seem to keep dex cool in the reservoir. The top radiator hose is not hard. It is hot but not hard, easy to squeeze.

I do not see any visible leaks anywhere. I filled with dex cool last night and drove 30 miles to work and now coolant gone again.

I do not see any leaks or puddles anywhere. AC is ice cold.

Temp gauge runs straight up n down 12 o clock. It's never ran hot. The low coolant light has never came on.

I cannot speak for what the previous owner has done but I have owned it for 3 months now and runs great!

I guess I am noticing this issue now because it's getting hot outside in Texas.

Thanks guys for any suggestions.

[Palf70Step]

Check the oil and see if it is getting into there. Intake gaskets are know to leak on GM V8 and V6s after a bit of time.

[shultzee13]

Nothing in the oil. All good there.

Just no pressure in top hose.

[shultzee13]

Could a reservoir cap cause this? One where the oring has hardened?

[406flyfish]

The intake gasket doesn’t have coolant going thru it. You need to fill it up and pressure test it to find the leak. The most common leaks are the water pump and the plastic heater nipple fittings.
Good luck

[hatzie]

The 01-06 Suburbans with Castech cylinder heads lost coolant through cracks in the oil return wells.
TSB 06-06-01-019B
http://ww2.justanswer.com/uploads/Bl...t_loss_5.3.pdf