balden57013

93 LS400 Heater blows cold air when car is sitting still, but works great when driving down the road. Any suggestions on where to start trouble shooting?

redalty

My 94 did the same thing. It turned out that the coolant level got low and it has gotten vapor locked. What i did was just take off the radiator cap when the car is COLD and slowly fill the overflow tank to the correct level. Yuo should see some bubbles coming up. After the bubbles slow down or stop completely, just replace the radiator cap and your set. Hope this helps you.

Suneet

When I had that problem it was solved instantly by adding more coolant fluid... check your levels, make sure you run your engine after putting it in to let it settle and get rid of the air.. (as was stated above).