Heater problems with a 2002 Chevy Venture - Sometimes it blows cold air and sometimes it works fine?

Question

When I am in start and stop conditions the heater blows cold air. When I am in a period of full acceleration the heater works fine. Another peculiar thing is that when the heater 'activates' or starts to blow hot air, I smell something through the vents for a brief period of time (less than a second or two).
Has anyone seen this and have any ideas what the problem may be?

Answer 1

i own a repair shop,and what its doing is probably it has gotten low on coolant and its not circulating real good,check this and if needed add coolant ,i think that will give you your heater back on it,good luck,i hope this help,s.

Answer 2

Start by checking your reservoir tank for the proper level of coolant. I would bet you'll find it low. Is the smell you get sweet? Perhaps a pinhole somewhere in a hose, or a very minor leak, have a close look at your heater hoses and make sure the clamps are tight. With the engine cold, remove the radiator cap. The coolant level should be up to the top of the neck of the filler, or to the full line if there is one. If it's low, add some there, and put the cap back on tight. Now make sure the reservoir is full to the cold line, and drive until the temperature gage is up to normal. Check the level again, it should now be at the "hot" line.

If so, drive for a few days, and check again. If it's down, you either had an air bubble (in which case the heater should be working fine now) or you have a leak.

If the latter, find and repair the leak.

If you still have problems, the water pump may be worn and in need of being replaced.

Answer 3

It sure sounds like the coolant level is low. Open the hood when the motor is cold and check the plastic overflow or surge tank for coolant level, it should be about half full when cold. Then carefully remove the rad cap, motor cold, and be mindful that it will be pressurized somewhat. The rad level should be totally full here. If not, either it has leaked out or has not been serviced for quite some time as all motors loose coolant because of the water steaming off when emptied into the surge tank when hot. Check for leaks, fix if nec, and refill coolant system. Re-check next time you go for a drive cycle and top up again if nec. Good luck.

Answer 4

humm looks like u have change the antifreeze recently, r broken a hose,it soulds as tho u may have a air lock,which means u have air in the heater core,best way i have found to get it out is to remove one of the heater core hoses and start it,i no u would think that the water pump would push it out if that was so,but some will not do that,u got to get all the air out of the heater core to stop this,better yet would be to unhook both of them,,take a funnel,,,and fill the hoses with antifreeze,u may have to lower one of then ,,,but what ever,u need to get all the air out of it,,whithet be with a water hose,r filling them with a funnel,,,good luck,,to dang cold to be going around with no heat,and the smell,who noes,,,could be something dead in thair,,r somone droped somthing down thair.if u removed one of the hoses,put it in a bucket r somthing.start it,,,u can detect how fast it is moveing,posably pluged core,,but anyway this will give u a place to start.1 more thing,is thair a vacum valve on the heater hose? is thair a bleeder on the top of the main radeater hose?if so bleed it,,,till u get antafreeze.does the fan blower blow hard?,laters

Answer 5

Where are the heater cores on a 2002 chev venture

Answer 6

Low coolant level.

Answer 7

that sounds like a water pump but it could also be your intake gasket coz those vans with the 3.4 engines have problems with it the reason i say it the intake gaket is because u said u smell something