97 Tahoe Antifreeze leak

Nov 08, 2006 10 Replies

I have a 97 Tahoe with the 350. I have been experiencing a slow antifreeze leak that I cannot find. I have replaced the water-pump and gasket, intake manifold gasket, checked the heater core and cannot find a leak. No fluid mixture in the oil. The only thing I have left to look at is the radiator and hoses? anywhere else to start looking?



Again it is a slow leak that does not leave a puddle.



Thanks in advanced for your assistance.



Steve


You have replaced all those items and haven't looked at the radiator and hose's ??

I'd start there. Get a pressure test done, you'll probably find it then.

R

Do two things before replacing the radiator.

  1. If you have an external leak not leaving a puddle it is because the water is leaking as steam, not liquid. To find the leak, apply pressure with a tester on a cold or no more than warm engine. Pump it up and wait. Each time the pressure seeps down, pump it back up. Keep this up for however long it takes to generate noticeable liquid. It make take an hour....especially if the leak is near a vapor space and you've got to vent out all the vapor first.

  1. If you are losing pressure in the test, but not seeing liquid...it may be leaking into your cylinder(s). Run a compression test to check this. You may have a leaky head gasket.

skimmer

Hello Steve, I too also own a '97 Tahoe, and experienced a few minor leaks over the years.

One, was a Heater Hose Clamp not even properly installed by the factory near the firewall, two, was a leak at the underside of the Resevoir Tank, noting the crappy little plastic Hose clamp on the line, I removed tank, cleaned, inspected, and replaced with a decent Stainless Steel Clamp, and three, the heater hose quick-connect on the top of the intake manifold was always showing dried anti-freeze, so I knew this was a problem, and decided not to replace with an original factory quick-connect, but rather a 3/4" manifold-heater hose fitting available from places like Auto-Zone-Checkers for just a few bucks.

Hope these suggestions may help you. Otherwise, as other posters have mentioned, a pressure test of the entire coolant system will definitely be the way to go. Usually places like Auto-Zone will do these checks for free. Mark

Thanks Mark ..... I will check these this weekend

Steve

Vortec 350's are well known for leaking intake gaskets (yes I know he replaced his) because of their cheap design and typically they leak in the rear and evaporate on back of engine and bellhousing without reaching the ground unless it is a big. leak. I had mine leak twice on my 2000 K3500 (under waranty) in 37K miles. They are fixing it again out of warranty for free am I am going to look at intake for possible warpage maybe cause problem twice in such low miles.

----------------- TheSnoMan.com

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