No heat at all

[blue4X4]

I have a 97 Venture and there is no heat at all. The radiator is full, the thermostat seems to be working by the guage that moves up and down. I put cardboard in front of the radiator causing the guage to heat up more. However the air I got was the same-cool. There are no antifreeze smells. Last year it worked fine, this year not at all. Any ideas?

[LMP]

You already have two 3.1/3.4 classic symptoms (no heat "at all" , fluctuating gauge) ....the third would be engine overheating..any sign of that yet? Remove radiator cap and start engine...look for bubbles escaping the radiator while someone else revs the engine in short surges... Head gasket failure is so common with these symptoms that it cannot be ignored as a real possibility....a very annoying and unwwanted possibility.
Can you peek under dash ..possibly remove glove box ..and see if you see or hear something move when you slide the temp control from cold to warm...(mixer door)..I'd rather want that blockage to be the cause, it has happened before.
Actual blockage of the heater core can be alleged...but rare.

[blue4X4]

Never any sign of overheating. It doesn't use any coolant either. I checked fuses. I have noticed how hot the radio and the climate controls in the console get on long trips(can nearly burn you when you touch the face of the console, radio area),even with the A/C on high. My wife also doesn't think the A/C gets as cold as it should have this summer. Is it possable for the problem to be in the controls (if it is stuck on cool even if I move it to hot)or in a sending unit/relay? I have also had it for a few years and never flushed the radiator in it. What is the best way to flush it? I will check the heater core for sounds and the radiator for bubbles. It will be 11 degrees today. Thank you for the ideas, I know very little about these newer vehicles.
-Ken

[LMP]

THe heater core is inside in the heater unit, under the dash...and from what you say, it would seem coolant circulates through the core and some heat gets under there. Probably the "mixer door" is frozen in the COLD position so that air bypasses the core without reaping any heat....dead actuators have been reported due to stripped gears.

THis is an electric motor that actuates the door. Getting to it might be a little arkward....but from what your'e saying, I think you have to..so you can seee if the shaft rotates wheen you move the temp control.
THis www.avigex.ca/xport/heater98.pdf (from Autozone.com) can help for the pictures however this is generic and your model (I'm almost sure) is the interior blower type as shown in fig 2 .

[blue4X4]

I replaced the thermostat and radiator cap. No change in temp. I do have brown clumps of gooey gunk in the radiator and I also have movement of coolant. As the van warms up the coolant rose out the top of the radiator some. I have an appointment to get the cooling system flushed and to have the heater core back washed. I will let you know what happens after that.

[LMP]

do not expense too much money on hope: all you say indicates blown head gasket....
sorry....read these...to the end:
http://www.automotiveforums.com/vbul...d.php?t=542580
http://www.automotiveforums.com/vbul...d.php?t=536281

[blue4X4]

well, Ill get the system all cleaned out anyway. It does need it done. It looks like it may be the intake gasket in the end. I have had several injectors replaced in the past couple years. The dealer probably didnt get the intake on very well the last time. Also, when I replaced the thermostat I removed the Throttle body and noticed a small quarter sized brownish puddle just inside the intake. You know I liked working on cars, but these newer cars blow.

[blue4X4]

OK, here is what happened. I had the coolinig system flushed. I got heat 140 degrees at the heater vent. By the end of the day it disipated to 75 degrees. It was still better then it was before but still not working properly. I have an intake gasket leak at the intake bolt near the water neck. I am now having the gasket repaired and they will back wash the heater core and apparently there is a removeable cross piece in a water hose fitting behind the motor below the throttle body. The cross piece has posed a trapping buildup problem and is suggested by GM to remove it.

So, I believe what has happened is the Intake leak has put oil in the cooling system causing goonk to build up in the entire cooling system. Remedy is to repair gasket, flush cooling system and heater core. Also, to remove the cross piece in cooling line while the intake is off. Repair is $900.00 for all. A head gasket alone(if it was that) would be $1400.00 repair.

[lynema]

I had the same problem with my 2002 montana.
Had an antifreeze flush and works great now.

[KJRich]

I just dealt with something similar for months on my Venture. The temp gauge would go up and down constantly, and the heater would alternatingly blow warm and cool air. Also, the rear heat didn't blow warm at all. It didn't use coolant, and it didn't overheat, and I tried to bleed it half a dozen times.
Finally I took it to a mechanic and it ended up being the waterpump.

[khakes]

2000 Montana - Slow Warm Up, No Heat - Comments see
posting at http://townhall-talk.edmunds.com/dir...ew/.f0fa8b1/31 by kennie. If the warm up occurs slow could be thermostat or other things... if no heat from vents even when engine is at operating temperature could be the aux heat pump. Good luck !

['97ventureowner]

khakes, this is a too old of a thread to be posting in. If you have some new info, please start a new thread.
From AF's Community Guidelines:
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