Question: Water is coming out of the back and the front of my 1996 GMC Yukon's engine. Is it the waterpump or the head gasket?
Answer: To find out for sure, fill the system with coolant and attach a coolant-system pressure tester. If it's a large leak, you should then be able to locate the exact spot where it's coming out. Very small leaks sometimes require adding a coolant-system dye. After running the engine for a period of time, you can then find the small leaks with a ultraviolet light. The area where the coolant is coming out will be a bright green. I can't tell you exactly where your leak is without seeing the engine, but the fact that it's coming out from the front and rear leads me to believe the leak is up high, possibly at the intake manifold or a hose. Leaks can be deceiving. The origin can be in one spot, but gravity and/or pressure causes the fluid to travel down a trail that leads to another area, before hitting the ground. You may have a leak in the front of the engine, but after following the nooks, crannies, and crevices, the fluid will be seen dripping out the rear.
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