LSH77VETTE

How big of a job is it to get to the heater core in a 77 vette? I need to check mine out as I am hearing a churning noise in the passenger side dash area that seems to get louder as I accellerate from a dead stop. I think it could be the noise of the fluid churning in the heater core possibly caused by a restriction. Is there a valve (vaccum operated) that shuts off the flow of antifreeze from going into the heater core in that area that might not be totally closing off thus making the noise?

Durango_Boy

Yeah I would suspect the vacuum valve on the passenger side. It's on one of the heater hoses routing to the box on the firewall. Replacing the heater core is not easy or fun, and it would be a good idea to check everything else. Sounds to me like coolant is flowing through the system as the system pressurizes from higher RPMs. This might be that valve not being closed all the way when you don't want heat.

LSH77VETTE

Thanks for your reply Durango_boy. I assume that the heater core would be accessible by taking apart the dash etc., or would it be accessible from the engine compartment? I know on other cars that I have had, I always had to remove the dash to get to it on the inside of the car. Sounds like a huge job according to your note above. Is this an all day job?

Durango_Boy

Yeah you have to remove the heater core from inside.

It's not a fun job, and depending on your skills and beer drinking it is an all day job.

LSH77VETTE

Sounds like I need to pick up a couple of cases of Silver Bullets before I tackle this one

Ragtop_Rob

Hmmm I guess the newer ones are different, but I easily removed mine in my '71 from under the hood. The entire job was not at all difficult.