Tubz_Z28

I have received a tremendous amount of help and information for my '01 Z28 from threads in this forum so I figured that I would give this a try. My wife has an '04 Bonneville with a 3.8 the problem is loss of antifreeze and lack of pressure in radiator. The car does not overheat and the heat blows hot. However, the overflow reservoir empties out after only a day or so. I have replaced the water pump, thermostat, upper radiator hose and radiator. I have searched for leaks paying close attention around the head gaskets and thermostat gasket to which I have found no evidence of a leak. I have checked the heater core and overflow reservoir and are not leaking. First thing in the morning I will do a pressure test to see if that turns up anything. I have been informed of an issue of a problem with the intake. And I will check the sparkplugs as well to see if there is evidence of a leak there. Any advise in this matter would be helpful and appriciated. Again I am sorry that this is not an LS1 problem, but who better to ask.

1_bad_TA

iTrader: (6)

Intake gaskets are known to be a problem. I'd put money on that being it. It might not show on the plugs fyi. Sisters Blazer had the same issue your having with the bonneville.

Tubz_Z28

will pressure test show this

Zlow28

iTrader: (11)

how much loss of coolant? Is there any smoke? color? Check your oil dipstick to see if the oil isnt milky. Also whenever the car is cold, top off the radiator with coolant or water, and have someone turn the car on with the radiator cap off. Check to see if there are any bubbles surfacing whenever you turn the car on.

The antifreeze doesnt just dissapear, and if its not being leaked, then its being sent somewhere else. Hopefully its not a bad head gasket.

Tubz_Z28

oil is fine, no smoke and as best as i can tell it only looses whats in the overflow that is what got me puzzeled. head gasket is my fear.

Tubz_Z28

intake gasket was the problem.bout $165 and 4hrs labor in the cold took care of it, thanx for the advice fellas.