neopj3

it's cold today and after about an hour of driving my heater never kicked over. any ideas?

jpandes

Yup, your heater core might be plugged up.

Why, I don't know. Mine got semi-clogged right after I had a rebuilt motor installed. My stock radiator also got ruined. I'm guessing the sealant used durning the rebuild clogged everything.

CantGoStraight

If you don't have it on the defroster or defroster/floor setting you won't get much heat.

neopj3

how do i declog it? would a radiator flush help?

Rocking Rotary

iTrader: (14)

maybe it would help but only for a little while it will clog again. Just replace and be done with it.

Also may want to check the fluid, it could be just that easy.

neopj3

where is the heater coil? is it easy to replace?

bajaman

No, the heater core is a ******* BITCH to remove and replace! You have to take your entire dash apart...it is friggin' crazy!

I unplugged my core that was almost entirely blocked from doing the block-seal-in-a-can trick. Let me find that write-up I did....it wasn't hard. Just took some time.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/unclogged-heater-core-yay-499700/

jpandes

Baja,

Do you think that this pump(below) will do the trick?

1/2 HP SUBMERSIBLE PUMP WITH FLOAT



Perfect for draining flooded cellars, ponds, boat bilges and pool covers. Automatic float switch turns the unit off at 1/8'' from the surface. Includes 1'' and 1-1/2'' universal fittings. Body is made of non-corrosive poly material.

• Motor: 1/2 HP, 120V, 400 watts
• Flow rate: 1855 GPH
• Max. lift: 26.25 ft.
• Discharge size: 1-1/2''

Harbor Freight has em on sale for $20. I need to fix heater core, too.

Thomas1277

Why doesnt the heater hardly work when its on vent. The only time I get real heat is when I put it on defroster or the floor

CantGoStraight

For some reason that's how it was designed to work (good reading in your owners manual) tells you all about little things like this.

Thomas1277

Thanks

DaiOni

If you need a new one, I can do them (genuine mazda) for US$230 - express freight to your door. ($243 if you want to pay via paypal - due to their fees).

bajaman

Oh yeah! That would do the trick just fine. Keep in mind that persistence is the key, when I first started I barely had a trickle coming out, with a lot of backpressure on the pump. By the time I was done I had full flow and next to no backpressure.

quicksilver_rx7

Does it take a long time for your car to reach "normal operating temperature"? If so, you could have a stuck (open) thermostat.

neopj3

no at all. only about 3-4 minutes. i'm going to go to harbor frieght and take a look. i just ordered the coolent hose kit from malloy and while i'm in there might as well. an air hose wouldn't help push some of the crud out would it? low psi of course

jpandes

Cool, The only thing I'm worried about is pushing too much pressure through the heater core and cause a leak insode the cabin. It sounds like your worked fine without any issues. Thanks for the tip.

jpandes

Cool, The only thing I'm worried about is pushing too much pressure through the heater core and cause a leak insode the cabin. It sounds like your worked fine without any issues. Thanks for the tip.