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heaters are warm but not hot

Posted: November 27th, 2008, 2:03 pm
by jon_young
any 1 got any ideas my heaters blow out warm air but never hot air

Re: heaters are warm but not hot

Posted: November 27th, 2008, 4:45 pm
by onlytrueromeo
heater core needs replacing!

Re: heaters are warm but not hot

Posted: November 28th, 2008, 12:18 pm
by jon_young
as in the heater matrix

Re: heaters are warm but not hot

Posted: November 28th, 2008, 12:22 pm
by solo_ryder
Check your coolant level first. If the coolant is low, then your car will not blow hot air at all, just warmish air.

Re: heaters are warm but not hot

Posted: November 28th, 2008, 5:38 pm
by wytbishop
Thermostat may be stuck open not allowing the engine to acheive full operating temperature. Thsi would be obvious because your temp gauge would show low temp...still I feel it's worth pointing out. Temp gauge should be slightly above middle regardless of ambient temperature.

Re: heaters are warm but not hot

Posted: November 29th, 2008, 10:47 am
by jon_young
well temp guage does never pas the half way ark not even when i flushed the rediator out the other week, the fans were working, and the water was steaming hot

Re: heaters are warm but not hot

Posted: November 29th, 2008, 1:21 pm
by wytbishop
Never goes above half way or never dips below half way. It should be at somewhere between 50-70% of the way to the top. If it's not your thermostat is probably just slightly open. So a trickle of coolant is being circulated through the rad all the time preventing the engine from ever getting truly hot.

It's about a $10 fix.

Re: heaters are warm but not hot

Posted: November 29th, 2008, 3:04 pm
by Bradhobbs
My MX-3 (HAD) the same issue I had to keep filling it up with coolant, changed heater core, change thermostat, did all I could to try and get hot air. Unfortunately I never did get nothing but warm air so I had to use the AC to keep my windows from fogging. :x Watch out and hope the head gasket isn't blown. (Mine was and it was burning coolant and eventually water got into the oil and stopped it dead in its tracks)

Re: heaters are warm but not hot

Posted: December 1st, 2008, 6:40 am
by SuperK
The B6 DOHC (You have the B5, correct?) thermostat will sit BELOW the middle mark... slightly.

If you haven't changed your thermostat, do it. Cheap, easy, and should be done from time to time.

My car was only blowing warm air, and it'd blow cold air whenever I took sharp right turns (meh)
I replaced the thermo and flushed and filled the coolant, it solved my heat issues. Toasty warm now.

Hopefully there isn't a clog somewheres on yours.


Not stepping on your toes, wyt, but the 92-93 MX-3's, the gauge registers as slightly above. The 94-95 4 bangers register slightly below. It's not a temperature difference, it's just a difference on where it shows up on the gauge. It's also possible that there's a difference on the canader (erm, canada) models on where it registers... so it could be different up in cold-land.

Re: heaters are warm but not hot

Posted: December 1st, 2008, 10:03 am
by wytbishop
I believe the Canadian models come with a colder thermostat. 88ºF instead of 79ºF. That would be the difference. Good catch.

Re: heaters are warm but not hot

Posted: December 1st, 2008, 12:29 pm
by jon_young
well i shall try with the thermo first as it is a quick and easy one