Tempature Rises And Falls Erratically


pretty bad
Typical Repair Cost:
No data
Average Mileage:
134,600 miles
Total Complaints:
5 complaints

Most Common Solutions:

  1. not sure (5 reports)
1999 Pontiac Montana cooling system problems

cooling system problem

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1999 Pontiac Montana Owner Comments

problem #5

Sep 022010

Montana 3.4L

  • Automatic transmission
  • 111,000 miles


Had the water pump, thermostat,radiator cap, intake manifold gasket, replaced, also bypassed rear heater feeds, bled system several times. No steam from exhaust. Still have air in the lines. upper hose is cold as is radiator cap, temp gauge is moving from 210-overheat. Any idea what else I can try ?

- , Bellmore, NY, USA

problem #4

Mar 082010

Montana 3.4L V6

  • Automatic transmission
  • 155,000 miles

I purchased the montana on Dec.2008,I've had it now for about 1 year and 3 months.It's really not a bad van, but here is my problem. It runs hot, and the fans don't come on. The main problem with overheating happened about three weeks ago, so i figured it was the thermostat and top hose. So i changed both. Since then it works fine for awhile but after about 3 days tempreture rises to 210 degrees so i check fluid and make sure everything is full but it is still overheating.Now i find the fans don,t blow unless the AC is on. I don't know what to do anymore can someone help me figure this out?

- , New Iberia, LA, US

problem #3

Jan 012010

Montana LX

  • Automatic transmission
  • 100,000 miles

this vehicle is a complete piece of sh*t we are now stuck in another town because the damn thing decided to go to hell not much warning took it to shop head gaskets are gone radiator is leaking and an 1800 dollar biil wtf now on here i read that this is a ongoing thing for everyone if there is a class action suit i want in on this this is messed up and pontiac should pay

- , Weston, WI, USA

problem #2

Feb 012008

Montana X

  • Automatic transmission
  • 140,000 miles

I have the same problem as the others with this vehicle, Only cools when the car is in motion, and then sometimes not at all. It sounds like lots of people had problems with this vehicle. I have spent about 1200 $ on this problem alone and it is not getting fixed

- , Essex Junction, VT, USA

problem #1

Jan 072008

Montana 3.4L

  • Automatic transmission
  • 167,000 miles

getting the coolant filled seems impossible. Park on a hill and the problem resurfaces. Also misfires occasionally.

- , Dillsburg, PA, USA

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