Hello,
Just found this forum today and what a lot of help it's been, but I haven't found my exact issue yet.

I am losing coolant rapidly (full reservoir maybe two months ago to completely empty today) but without any visible leak--is it possible this is connected to my heating issue or should I be concerned about something much more serious?

Back story:

2001 ES 300 with about 130k miles sat in storage for a year and when I got it out the AC didn't work. I assume an A/C compressor issue, which is above my level to replace so I didn't address it immediately.

Heater has been acting up, sometimes not pumping hot air but so far I haven't been able to predict/determine when it will blow hot and when it will blow cold. Two days ago I started hearing a squealing from under the hood when I turn on the heat; I'm thinking belt issue related to the original A/C problem.

I checked coolant today and it was completely gone. I refilled with almost a gallon of coolant/water and operating temp is stable right at the halfway mark. Heat is back to blowing hot but still with a squeal at the start.

So could my heating system be consuming coolant? Without any visible leaks I can't see how else I'm losing it so quickly.

Thanks if anyone can help!

Kevin

 

Start by having a pressure test of the cooling system done.

A simple possibility is that you have/had air in the system. This could explain the APPARENT loss of coolant as well as the intermittent heat issue. This could happen if you had your Coolant changed recently. In that case, you may have to burp the system to make sure that all the air come out.

Either way, a pressure test is mandatory as a start.

The results will than determine what the next logical step should be.

Phil