k so u turn the heat on and immediately the gauge drops? like turn on heat and instantly it goes back down 2 160? or does it slowly go back down to 160? if it slowly goes down then ur engine is overheating and u need to get that looked at b4 u warp things with the heat. how long ago did u replace ur water pump?

 

instantly. I replaced water pump and therm 2 days ago.

 

hmm did u ever check the temp sensor

 

not yet cuz I didn't think that would make my heat stop working. but I tried everything else so I will give that a try also

 

Pertaining to the leak, where are you finding the loss? On the ground, engine or in the coolant overflow jar?

I had the same type of thing going on and found that I had a huge air gap somewhere in the system. OnceI cleared the air everything was fine. I opened the air release screw (near the thermo neck) and ran the engine until warm, while at the same time squeezing the upper and lower rad hoses until the air pocket was forced out the rad neck (I also left the rad cap off during this process).

I was seeing the same actions that you were before I did this.

 

You have to bleed the lines with the Cabin Heat on Full Blast. You have to make sure that there isn't air in the Heater Core. If there's Air in the Heater Core ... once the system comes up to temp ... the Air Pocket will lower the Level of Coolant in the System or ... it there's plenty of Air in the Heater Core ... reduce the volume in the system to levels low enough to avoid the sensors.

Run the car with the Heater on FULL Heat. Radiator Cap OFF. Meat thermometer sticking in the Radiator Fill wired so it don't fall in. One gallon 50-50 Mix in a pail. Turkey baster. Let 'er rip. Once the Thermostat Opens and the Level in the System drops ... add more Coolant a little at a time. Don't fill it right to the brim. Leave some room for air to escape. Have an assistant with a gentle touch raise the RPM's to 15-Hundred. Get the Coolant moving through the Block and Heater Core. Now, add more Coolant to the Level as Pump moves any air in the system forward to the Radiator where it will escape. As it does ... continue adding Coolant until NO More Air Bubbles appear at the Filler Neck. Now, comes the fun part. Have the assistant run the RPM's up to 2-Grand ... FILL the Radiator right up to the Brim with Coolant. If there are NO Bubbles and the Level is holding steady ... Fill it to overflowing and put the Radiator Cap on Tight. Don't forget to read and record the Temp on the Meat Thermometer when the Coolant is circulating rapidly. Return the Meat Thermometer after cleaning. Keep the Turkey Baster for other jobs and buy the house a new one.