We have 1999 Silhouette Van we have heat when driving but cools down when idling at a stop. Low coolant came on filled system checked several more times, then checked for air in system by using the 2 bleeder valves no air came out. Van comes to normal operating temp like usual. Does anybody have any ideas? Please help.

SOURCE: '95 silhouette mini van

Its was my neighbor wanting the info and she decided to send it to the scrape yard for $200.
Thank you for replying

SOURCE: cant find bleeder valve foe coolant system on 96

dr_greg is incorect. The bleeder valve is on the thermastat housing near the intake manifold. Follow the hose from the top of the radiator to the the engine. Look for something that looks like a 12mm head nut with a metal nipple comming through it. If you change your coolant but do not open this valve untill coolant flows from it you may cause an air pocket to remain in your engine, possibly causing your car to over heat.

SOURCE: is there a coolant bleeder

If you want to put coolant in and you have air in the system.
1. Look for a flat plug on one of the upper coolant pipes unbolt and fill at that point.
2. You can also take hose of radiator and fill that way if you can't find the plug.

(If your looking to drain the radiator should have a drain at the bottom of the radiator on left or right side.)

SOURCE: where is the coolant bleeder valve on 2000

On the engine next to the thermostat housing on most cars. It is a regular flathead screwdriver type screw. if you can't find it. Then slowly , without removing it, turn the radiator cap at operating temperatue. Until you hear it hiss and only coolant will come out. Do this very slowly andd carefully. The water is hot. Be careful.

SOURCE: GM 3100 coolant bleeder valve, where is it, Thank

THERE IS ONE IF YOU FOLLOW TOP RAD HOSE BACK TOB ENGINE YOU WILL FIND IT ON THAT HOUSING SMALL.