Last post on Sep 02, 2012 at 9:29 PM
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Pontiac Montana, Pontiac Montana SV6, Heating / Cooling, Van
#1 of 3 2006 Pontiac Montana 3.5 No HEAT!!
Dec 08, 2011 (8:25 am)
I am having an issue with my 130,000 mile 2006 Montana not sharing its heat. The van does not over heat and is running at a normal operating temperture. It will give off a little heat and three seconds later blows cold. For awhile it would give off warm when you were driving and it would go cold at stops. It has even stopped doing that. Serpentine belt broke two months ago and replace it. Just replaced the EGR valve and the cat. I also had to replace the fan knob that got broke. Any Ideas I am thinking maybe thrmostat, or a blockage in the heater core maybe?
#2 of 3 Re: 2006 Pontiac Montana 3.5 No HEAT!! [radtad]
Dec 08, 2011 (9:18 am)
You can see my other posts on this... there are quite a few. But based on what you are telling me I would guess that there are two aspects to your problem -maybe a third. I've experienced EXACTLY the same thing with this van. The head when it is cold out -15bones is not great even right off the factory line - so you can't have a high expectation off the starting line. If you are rear heat and the vehicle is purchased in canada or cold climate area then it probably has a auxilary coolant pump. It is located inches from the front/left corner of the coolant reserve when you are facing the vehicle. The pump is actually a motor with a magnet that drives a fan that pushes fluid into your heater core and to the rear heater core. If you have one of these they get bungged up... my van is a 2000 and this was my problem... the fan was no longer turning and was completely bungged up... your van is a 2006, I can't imagine this happening so soon but it is possible. I flushed my heater core myself and cleanned the aux pump and all was well - i have extensive posts on Edmonds on what I did number kennie. If your motor is not overheating then I cannot see what a thermostat change would do to help... it is already opening/closing if you are not overheating. The only other thing could for you to add coolant or bleed air out of your system using the two pins... possibly you are not getting enough flow but I doubt this would cause your low heat issues. When I sped up the engine I had more heat... this would explain that you are not getting enough fluid FLOW through your heater core... thus the aux pump or core bockage. When I flushed mine (both ways) allot of debris came out. Good luck.
#3 of 3 Re: 2006 Pontiac Montana 3.5 No HEAT!! [radtad]
Sep 02, 2012 (9:29 pm)
I am not totally familiar with the Montana van per se, but I do know that 2006 was the time frame of the evil Dexcool engine coolant. There is a class action lawsuit that has now expired that speaks to the chemical reaction of this coolant when heated and exposed to atmospheric air for a prolonged period. ie: as when the coolant level has become low. The material turns gelatinous and can stop up the heater core and other critical cooling hardware. It happened to me when engine service was being performed. The other reply has the person diligently flushing out the cooling system and replacing it with some of the more excellent non automotive manufacturer producers of coolant. The global coolant has superb all-around properties and compatibility. You may wish to convert to better coolant.