While driving my 69' lately, I've noticed the aroma of anti-freeze and also the light foggingjust above the defrost ventsat the windshield, which tells me that my heater core has developed a leak of some sort. No moisture around heater or carpet. So untill I replace the heater core, can I connect the supply and return line together(in the engine compartment) for now withoutcausing problems elsewhere? (Non-ac car) Thanks in advance

 

i dont think it would cause a problem.

 

No problem at all. That's what they do when it's a heater delete car. Just have to keep the coolant circulating...

p.s. (it's not much fun changing out the heater core...so if you buy a new replacement, have it pressure tested before you install. Sometimes even new ones leak. Unfortunately, I know)

 

Thanks. I was also planning to just plug both ends but a loop sounds more logical. I will also pressure test the new heater core when it arrives.

 

Yes. Do not cap the lines but loop them...

 

Thanks FlightMechYJ68. I almost capped the ends,after a buddy of mine said he had the right size plugs instead I just looped the lines. The coolant odor and fogging of the inside of my windshield has ceased.