99 Tahoe 5.7 leaking coolant

[Jconn813]

Hey guys my names Joseph I have a 1999 Tahoe 5.7 4x4 and it is gushing coolant from the starter area replaced the lower and upper intake manifold gaskets this week becuase they were gushing too. Cranked it up for the first time and it just started gushing from the starter area looked up and can’t really tell where it’s leaking from could some one shed some light on this please. Oh also I used felpro intake gaskets.

 

[east302]

Knock sensor is kind of above that area, lower side of the block. That or heater hoses would be another thing to look at…especially if the volume coming out is really high.

 

[OR VietVet]

Welcome to the forum. Likely what @east302 said or maybe a freeze plug.

 

[Hoesgottaeat2]

Tell us a little about why you replaced the gaskets initially? Any coolant leaks prior to that? What coolant related items did you disassemble or touch in the process of replacing the gaskets? The plastic heater hose fittings in that vicinity get brittle over time and may have gotten compromised if handled roughly during the intake gasket replacement.

 

[Chrisgotit]

1999 GMC Yukon Denali is leaking puddles of antifreeze but reservoir is not low

 

[OR VietVet]

1999 GMC Yukon Denali is leaking puddles of antifreeze but reservoir is not low

Hell of a way to welcome yourself to the forum.

Lots more info needed and please please please, don't think that you get to join for free advice without vehicle info and personal info.

Not a chance that there are puddles, you know where fluid hits the hard surface and spreads and makes you think is a lot of fluid, and reservoir is still full. Or is "reservoir not low" mean something else? or it is not coolant?

 

[Hoesgottaeat2]

1999 GMC Yukon Denali is leaking puddles of antifreeze but reservoir is not low

If the leak was pre-existing, the former owner may have added stop leak to the overflow tank, causing it to plug up. Remove the overflow tank and make sure fluid flows through the hole on the bottom. If not, clear it out and then flush with some water before reinstalling it.

Then continue to monitor it to confirm your radiator cap is working properly as well.

 

[YukonGTmaster]

I had bad coolant leaks on my '97. It was leaking from the quick disconnect fitting at the intake and running down the back of the engine. I replaced both the hose and the fitting at the intake. There was also a pinhole leak at the two small water pump hoses, which I replaced with OEM GM parts. Then I got the lower intake manifold off, and had major pitting and corrosion at the coolant port. I had to hot parts washer, sand blast, and epoxy the area before reassembly with new gaskets.