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Pontiac Montana Heating / Cooling Problems

94 messages,  Last post on Apr 06, 2013 at 7:52 AM

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What is this discussion about? Pontiac Montana, Pontiac Montana SV6, Heating / Cooling, Van

Messages Page 7 of 10

#59 of 94 water pump??????? by hurricane_db

Apr 14, 2010 (1:50 pm)

ok so here we go i have a 2000 pontiac montana that was overheating i turned on the heater and it was blowing cold air.i thought that was the thermostat that was bad so i changed it, still same problem. i then notice my coolant was pretty nasty with floaties that looked like some sort of stop leak so i flushed the system, still same problem. now im thinking the water pump but i dont know how to tell if that is the solution. the whole time it was overheating the cooling fans never kicked on so could it be something as simple as a relay or do i just change the water pump and go from there.im tellin you im gettin close to just throwin this van away.

#60 of 94 02 pontiac montana power loss by sar781

May 06, 2010 (9:35 am)

Someone please with knowledge help me, this vehicle has got a 3.4 lt engine, the check engine light is on, half my power has dissapeared, and theres a metalic screeching comes from underneath the vehicle when you give it gas. Also it wants to run hot because of this and I just had the plugs and wires replaced, oil changed ad new air filter put in. I replaced the fuel filter myself, that is good. Also when you give it gas you dont get much reaction from the engine, half of what its supposed to do, its got 153,419 miles on it, any suggestions????

#61 of 94 02 pontiac montana power loss by armes

May 06, 2010 (6:37 pm)

Did this problem start before or after the tune-up and oil change?

#62 of 94 Re: 02 pontiac montana power loss [armes] by sar781

May 08, 2010 (8:41 am)

Replying to: armes (May 06, 2010 6:37 pm)
After the tune up, but right after I had the plugs and wires ect changed, everything run fine, its been gradually building up to this, last I checked the code reader from the dealership indicated something with the emission system ore something, cant remember.

#63 of 94 Re: 02 pontiac montana power loss [sar781] by armes

May 09, 2010 (5:51 pm)

Replying to: sar781 (May 08, 2010 8:41 am)
Overheating, bad emmission readings, rough running and loss of power can be caused by several things. Having too rich of fuel mixture and liaking head gaskets can cause all of these symptoms, Are you loosing coolant from the system with or without visible leakage from the cooling system?

#64 of 94 Re: 02 pontiac montana power loss [armes] by sar781

May 12, 2010 (8:34 am)

Replying to: armes (May 09, 2010 5:51 pm)
No I am not loosing coolant of any kind, it just has a loss of power, and a metalic vibrating kind of racket coming from underneath the vehicle when i gas it going down the road. Engine light is on, oil is good, so is the coolant. Fuel filter has been replaced its good. Might make a note here we did move from Oregon to Oklahoma, major climate change, is there a way to reset the computer without going to find someone with a code reader????

#65 of 94 Re: water pump??????? [hurricane_db] by ecoffin

May 13, 2010 (4:11 pm)

Replying to: hurricane_db (Apr 14, 2010 1:50 pm)
Had the same problem with my 2002 Montana. Motor was over-heating but only cold air was being blown.
 
On my first visit to the garage, the mecanic said it was my thermostat and changed it. The problem went away for two weeks and came back.
 
Went back to the garage and this time he flushed by cooling system. This worked for about two weeks and the problem came back.
 
I decided to change garages. This time the mecanic identified the problem! There was a tiny hole at the bottom of the radiator where air was entering and thus creating a blockage in the cooling system.
 
Apparently, the reason why the problem was going away for two weeks previously was that air in the system was removed when the mecanic would change the thermostat or flush the line and it would take about 14 days to accumulate sufficient air to cause the problem to return.
 
I am happy to report that the problem has not returned yet. Mecanic appears to have identified the smoking gun.
 
You may want to check this out (very difficult to detect these holes because they do not necessarily cause a visual leak of Prestone on your driveway).
 
Best regards,
 
Eric

#66 of 94 Re: 02 pontiac montana power loss [sar781] by armes

May 13, 2010 (6:35 pm)

Replying to: sar781 (May 12, 2010 8:34 am)
You used to be able to take the fuse for the ECM ( computer ) and wait 30 seconds or so, put it back in and start/drive the vehicle for a few miles while it relearned everything. Now you have to go to the dealer and have them check/reprogram through there computer systems. Need to have engine codes read to find out what makes the check engine light come on. Most local auto parts stores will read the diagnostic codes for free. Garages charge $ 40 to $ 60 to check diagnostic codes.

#67 of 94 Re: water pump??????? [hurricane_db] by armes

May 13, 2010 (6:50 pm)

Replying to: hurricane_db (Apr 14, 2010 1:50 pm)
I have a 02 that started overheating the same way. They told me I had leaking head gaskets. Spent $1300 for that and still had the problem with overheating and floaters in the radiator. Floaters turned out to be engine oil. I was coming from a small crack in the oil cooler. It was bleeding oil into the cooling system because the oil pressure was higher than the water pressure in the cooling system. They took the cooling lines off the cooler and bypassed them together. This isolated the oil cooler to oil only. After the engine warmed up, the crack opened up and oil started coming out the water ports on the cooler. Replaced the cooler, cleaned all the oil out of the cooling system ( hard to do ) and the problem went away. Cost $245 fo a new cooler. They installed it for free ( they got 1300 the first time for unneeded work )!!! The oil had coated the inside of the cooling system and reduced the ability to transfer heat.

#68 of 94 wtf by julieinid

Jun 24, 2010 (8:25 pm)

All I did was flush the radiator on my 2001 Pontiac Montana now it over heats like crazy! can't even make it out of driveway, what's goin on?

Messages Page 7 of 10

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