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loosing antifreeze

11-02-2010, 08:57 AM
95 jimmy 4.3 have to keep adding af every week but dont see any leaks,no smoke from tailpipe either.any good stopleak products to use or do they clog then ruin system. thanks k

11-02-2010, 04:38 PM
Stay away from stop leak products, they cause more problems! A common place for coolant to leak on the 4.3L is from the lower intake manifold gaskets. Usually in a corner where the intake meets the cylinder head and block. A pressure test, a flashlight and a small mirror will help locate the leak. There is a dye you can add to the coolant and use a black light... the leak sticks out like a sore thumb!

11-14-2010, 07:02 AM
is this a hard fix or just a pita to do. thanks for you reply

11-14-2010, 08:15 AM
Nothing difficult about it. There is a thread in the Blazer "How-To" section that will guide you through the repair. If you take pictures when you take it apart, it helps for reassembly. Keep track of where the bolts go and you'll be fine. Takes about 4 hours if you've never done it before. The only "special" tools you'll need are a torque wrench for tightening the bolts that hold the lower intake to the cylinder heads, and a tap and die set to clean the threads in the cylinder head and the LIM bolts. Very important to use the proper torque specs and tightening sequence. Felpro makes a redesigned gasket that, if installed correctly, will not leak. Part #MS98002T, check with the auto parts store to make sure it fits your engine, (it doesn't fit all 4.3's).

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