Why is my 1999 montel carlo 3800 leaking water from top of motor?
The intake manifold gaskets have failed. These motors are notorious for this. Have the upper and lower intake manifold gaskets replaced. Inspect the upper intake for cracks. It's plastic and notorious for cracking over time. Once the repair is made immediately have the oil changed twice. Have the shop drain the oil and install a new oil filter then refill with fresh oil before the engine is even started the first time after the repair. Let the engine idle for 30 minutes. Then shut it down and repeat a second time. This is essential to prevent a spun bearing if antifreeze has also leaked into the crankcase. Which often is the case on these. Finally, whatever you do, don't try to Band-Aid it with any kind of "stop leak" product. That will only cause other problems such as overheating and a clogged heater core. HTH. -Jim
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