1999 Pontiac Montana overheating

110,000 MILES • 6 CYL • FWD • AUTOMATIC
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PHROTH
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I have heard many tales about troubles with this van, and here is mine.
My wife was telling me that the temp guage would alternately should that the engine was beginning to over heat and then would quickly drop. Along with this, she would have cold air blowing and then hot air. Naturally, I figured that the thermostat was going bad so I untook the monumental task of replacing it. Upon doing so, I tried running it and I began getting the same thing. I would get very hot air from the heater and then I would get cold air and the temp guage would climb. then things would go the opposite way---the temp guage would go down and I would get some very hot air. Is there a sensor somewhere that I need to replace?
Dec 28, 2009 at 2:15 AM
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MURRAY JAMIESON
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if you have a 3.4L engine you have the famous "Dex-Death" cooling problem....my 2000 Montana had the exact same problem....the problem is the Lower Intake manifold Gasket is being eaten away by Long Life Engine Collant (Dex-cool)....goggle "gm 3.4 L engine and read all the info. on this problem....my repair bill was $2000.00....sorry for the bad news....there are also a few other web-sites dealing with this problem....good luck
Jan 2, 2010 at 8:43 AM
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