Heater question.

[srbigbutt]

When I bought my 75 280z it had the heater core blocked off and they hose looped back into the block. The car was his sisters and she had passed away and he didn't know what was wrong with the system. So what i'm wondering, is there anyway to know what exactly is the problem without making a mess? Should I just plug everything back up and turn it on and see where if it leaks and from where.

[sblake01]

If you do that, you will likely end up with a mess. I would do a visual inspection under the dash where the heater vavle, hoses, etc. are. It might just be one of the small connecting hoses. My heater valve developed a leak which soaked the carpets and they had to be pulled and replaced along with thouroughly drying my still 'rust free' floor pans. I also replace the heater core while I was in there but the valve was where the leak was. A heater valve for a 280Z was tough to find in 2002 so it's probably even tougher now. There are two types. One for cars with factory ac and one for cars without and they're not interchangable.

[peterc]

Can't think of any way to tell if/where any leaks are without running some liquid through it. You don't have to hook up the rad hoses though. Connect a larger funnel to a 5 foot length of heater hose connected to the inlet side of the heater core. Make sure that the heater control lever is in the ON position (opens the valve allowing water into the core). Slowly pour plain water into the funnel (held overhead). Gravity will force the water through the heater core and out the outlet side into the engine bay, onto the ground. You should be able to isolate where the core is leaking inside the cabin without making too big of a mess. And it will be an easier cleanup than a water/antifreeze spill.

Likely suspects for leak inside the cabin are cracked hoses or the inlet valve itself.

Good luck

p

[srbigbutt]

Well looking at it from under the dash it looks like the leak is coming from the heater control valve/hoses area. Hoses look pretty nasty. Where can I find just the hoses. My car has factory AC by the way.

I'm thinking I will replace the hoses and try to pump some water through and see if I can see any leaks. If I do I will try to hunt down a Heater control valve.