Another engine/heater question

[CharlieZ]

My car always took a long time to register temperature on the gauge. about 10 to 15 miles of driving. Getting ready for winter, and thinking the thermostat was likely not the right type, I bought a new Mazda 2 stage thermostat. Before installing it my heater core sprung a leak. I shunted the heater with a piece of hose.

Without installing the new t-stat but after bypassing the heater, I noticed my engine heated up a lot quicker than it did with the heater in the flow. I start getting an indication on the gauge in about 3 to 5 miles.

Could bypassing the heater core make that much difference - all else being the same? Maybe it's partially clogged-up? I've always had heat but not soon and not much.

Any thoughts?

[91_festy_Gl]

Both my festies take awhile to heat up aswell.

[ericsmith32]

This is why I love my automatic in the winter! That puppy warms up in a mile it seems. Dad's 5 speeds take forever to warm up!

[Darlo]

Check the sticky on the T-stat issues, there is a bunch of info there....

I am having the same type of issue with my 5-speed. I think it is the T-stat stuck open, as the car never gets to temp, and my heater is only ever luke-warm! I am picking one up later for $7 + $0.50 for the gasket!

Make sure you get the two stage type!

[Pu241]

Darlo, me thinks if your car's T-state is fine, if not your mileage would suffer.
Often times the connection at the thermistor for the gage is corroded or a poor connection, and the gage reads poorly. Cleaning the connection can help a lot. Sometimes a new thermistor is in order.
However for low heat output of the heater core, I'd suspect blockage or sludge buildup.
Might want to try back flushing the heater core or using a radiator flush to get the crud resuspended and back into solution so it can be flushed out.

[ericsmith32]

Check the sticky on the T-stat issues, there is a bunch of info there....

I am having the same type of issue with my 5-speed. I think it is the T-stat stuck open, as the car never gets to temp, and my heater is only ever luke-warm! I am picking one up later for $7 + $0.50 for the gasket!

Make sure you get the two stage type!

In my dad's Festiva one has the 2 stage and the other a regular. Truthfully I don't see a difference in the two! Both warm up exactly the same.

[muscle_Car1]

Well three great exchanger is just another radiator. So if your moving air over it before it's time' then your just cooling the car more. Just a thought. The guy I carpool with hops in his car, starts it, then turns on the fan/heat to max. :roll:

[TominMO]

In my dad's Festiva one has the 2 stage and the other a regular. Truthfully I don't see a difference in the two! Both warm up exactly the same.

+1. My Aspire has a new 2-stage, my Festy has a Stant. Both warm up about the same.

[Occhty]

I don't want to start a debate here, but it's not a two stage thermostat, it's actualy a fail safe thermostat. But don't take my word for it, take your expensive two stage (fail safe) thermostat drop it in a pan on the stove and test it yourself. That little valve won't open until way after boiling, witch is to hot for normal operation of your car.
That's why when you have a good clean coolant/heating system you don't notice a difference between the two thermostats. There are however two different temp options when chosing a thermostat, 180 or 195 deg. If you look on the bottom of your thermostat, it should be stamped on the copper part. I'm on festy 27 and the biggest heating problem I've found is people will flush the heater core on the inside but they never clean the outside (air flow side). Whenever I get a festy that dosent heat, I change the thermostat, and a normal flush. If after that it still dosent heat, pull the heater core box from under the dash and disassemble and flush the air flow side. It's a big job and a pain but I have never had one that didn't cook your butt after that. And if you have air conditioning, ugh!! Bigger pain. Anywho.... Just my two cents.... Hope that helps