I back flushed my heater core today due to weak heat output. Holy crap.... literally!

 

Ya I really should do that...

Part of me wants to do it before winter....a bigger part of me wants to wait til the spring.

 

Easy to do. 10 minutes max. The difference was instantaneous. I'm in NY, so heat is a necessity.

 

I just REPLACED my heater core. Ugghhhhh what a job.

 

Oh I know about harsh winters...I'm probably no more than 2 hours from you. I think we all somehow know this winter is going to be rough again as well.

It cranks heat for now, and the cooling and heating systems seemed to have been done somewhat recently as well by the PO, but it's one of the next things on my to do list.

 

I didn't want to have to replace mine, that's why I opted to try the flush. I hear they are a pita to do. Don't know when the last time, if ever mine was done. It rocks now! I'm running straight up water for a few days then will redo the core then the rest of the system.

 

I find that removing that entire heater control valve assembly helps as well... besides... its just a crappy design anyway...

 

I've had my '94 for only a few weeks, but did notice the heat isn't impressive. Maybe a flush is needed on this one too....before the brass monkeys arrive...

 

I'm not going to say this is the best way, as there are a lot of ways performed on this. I flushed it, filled the system back up with straight water. Ran it for a couple days and reflushed. Got more crap out. Flushed till it ran clean. Filled entire system back up with 50/50 now the heat really cranks. Easy project. Gonna be cold before you know it.

 

This may sound like a dumb question but is it necessary to drain the coolant, even partially before you remove the hoses going to/from the heater core? I did a system flush a few months back but didn't do a specific heater core flush and rather not drain the system if it can be avoided. Going by touch/squeeze, it feels like the two heater hoses are empty when the engine is cold. Thanks.

 

They shouldn't ever be empty. If they are, then there's air in the system. Typically even if you do get air it will eventually bleed out into the overflow, and as long as your overflow bottle doesn't go empty it will suck coolant back in when it cools.


So if you disconnect heater hoses without at least partially draining the coolant first, you will drain some coolant when you disconnect them!

 

Thank you. I squeezed the hoses again and they do indeed feel full. Looks like I'll need to partially drain the coolant.