3.0 cooling system pressure test

[Sleeveen]

91 3l wasn’t winterized properly,did a pressure test on the cooling system,couldn’t get it to pressurize,and I could hear air coming from the exhaust.Cracked block?

 

[havoc_squad]

If the raw water inlet of the TSTAT housing and the hose going to the exhaust manifold are sealed properly for the test, you should not be getting pressure loss unless you have a leak or a cracked block.

I don't know the recommended PSI amount suggested.

The most common place for the inline 4 3.0L to crack is on the port side of the engine where the manifold is. It cracks right below where the engine head and block meet, near the casting plugs.

It's rather easy damage to spot/find if one takes off the exhaust/intake manifold.

 

[Sleeveen]

Thanks. I can’t get it to build up any pressure,it’s like trying to blow up a balloon with a hole in it

 

[Scott Danforth]

List how you prepared for the pressure test, be specific

Did you plug the line that goes to the exhaust manifold?

 

[Bt Doctur]

if you removed the water inlet hose from the T housing and introduced air into the housing you should hold pressure unless there is a crack Or add a water hose instead of air and look to see where its squirting from

 

[GA_Boater]

Open or closed cooling on your 3.0?

And welcome aboard.

 

[Sleeveen]

Open system,plugged the hose going to the manifold.Going to try water instead of air and thanks for the welcome

 

[Scott Danforth]

air molecules are smaller than water molecules.

if you plugged the hose going to the manifold and you plugged the hose coming from the raw water pump in the drive and pressureized it to 15 psi and it doesnt hold. you have a "thermal-declination-induced-hydro-expansion-breach"....... in other words, it froze and your block cracked.

it will have cracked at the top of the water jacket just under the deck on the outside, and inside the water jacket just above the pan rail.