Heater goes cold unpredictably.

Joram van Zyverden

Asked by Jan 04, 2016 at 03:51 PM about the 2005 Toyota Tacoma 4 Dr STD 4WD Extended Cab SB

Question type: Maintenance & Repair

My heater goes cold unpredictably but possibly
more often when idling. The temperature gauge is
normal. What's the problem? Is it fixable by me, a
fairly capable amateur?

3 Answers


Most likely just low on antifreeze. You may need to flush the system, especially the heater core. If you are handy, its not to hard. Plenty of videos on youtube . Try just adding some coolant to the reservoir tank first though. There should be full hot and full cold marks on the tank to help get the correct level. If you are a bit low, watch it for a while afterward to make sure you aren't losing it regularly, could mean more problems.

2 out of 2 people think this is helpful.

Of course the first thing to check is the coolant level cold, also check for oil int the coolant and coolant in the oil, if those check OK then you may want to check the cooling systems ability to hold pressure, if the water pump is the least bit weak or leaking it may not be able to deliver a good flow to the heater core, next check the heater hoses, make sure they are not collapsing while running at full operational temps. the only other thing I can think of is a restricted heater core, so when the water flow slows down like at an idle it doesn't have enough flow to sustain good heated air flow. HTH

Joram van Zyverden

Thanks! I'll check the level.

Your Answer

Add photo

Related Questions

  • How long will 1994 last with a 146,600 mmiles on it 6 answers

    1995 Toyota Tacoma 2 Dr V6 4WD Standard Cab SB



  • Check Engine Light 2 answers

    I have a 1985 MR2 MK1. For the entire time I have owned the car (more than 30 years), the check engine light will come on occasionally and unpredictably. Sometimes after I have driven the car for a ...

    1985 Toyota MR2


    Maintenance & Repair

  • 2014 Avalon Ltd won't start 5 answers

    My 2014 Avalon Ltd. is two weeks old, this morning it wouldn't start....just clicking ......Toyota sent a tow truck, boosted it and it started right away. Toyota tested the battery...said it tested ...

    2014 Toyota Avalon Limited


    Maintenance & Repair

  • VSC Icon Alarm Comes on When Turning on dry roads 1 answer

    We have a 2006 Toyota Sienna. The vehicle has 188,000 miles on it. The VSC icon comes on along with the alarm when driving on dry roads and when turning whether on flat or downhill travel with the bra...

    2006 Toyota Sienna LE AWD


    Maintenance & Repair

  • Problems starting 2005 Toyota Camry XLE 4 answers

    I am having trouble starting my Camry, and the very same thing happened about a year ago. Back then, despite having it in the shop multiple times, and sometimes leaving it with them for days, the ca...

    Toyota Camry


    Maintenance & Repair


Looking for a Used Tacoma in your area?

CarGurus has 30,504 nationwide Tacoma listings starting at $2,850.


Search Toyota Tacoma Questions

Toyota Tacoma Experts

#1 FordNut
Reputation 840
#2 Tom Demyan
Tom Demyan
Reputation 830
#3 genxer36
Reputation 300
View All

Related Models For Sale

Used Toyota Tundra"
621 Great Deals out of 26,774 listings starting at $2,500
Used Nissan Frontier"
428 Great Deals out of 20,761 listings starting at $2,500
Used Ford F-150"
3,267 Great Deals out of 216,697 listings starting at $1,500
Used Toyota 4Runner"
367 Great Deals out of 18,996 listings starting at $2,200
Used Chevrolet Silverado 1500"
2,447 Great Deals out of 144,719 listings starting at $1,995
Used Chevrolet Colorado"
316 Great Deals out of 17,476 listings starting at $2,495
Used Ford Ranger"
264 Great Deals out of 7,709 listings starting at $988
Used GMC Sierra 1500"
1,024 Great Deals out of 56,926 listings starting at $2,300
Used Jeep Wrangler"
461 Great Deals out of 16,417 listings starting at $3,400
Used Dodge Ram 1500"
522 Great Deals out of 13,739 listings starting at $995
Used Nissan Titan"
224 Great Deals out of 13,315 listings starting at $4,500
Used Toyota Camry"
1,590 Great Deals out of 98,367 listings starting at $895
Used Toyota Corolla"
1,412 Great Deals out of 67,098 listings starting at $1,295
Used GMC Canyon"
128 Great Deals out of 8,624 listings starting at $1,500

Used Cars For Sale

2017 Toyota Tacoma For Sale
11,212 listings starting at $21,961
2016 Toyota Tacoma For Sale
32 Great Deals out of 2,768 listings starting at $19,900
2015 Toyota Tacoma For Sale
81 Great Deals out of 2,585 listings starting at $14,900
2014 Toyota Tacoma For Sale
84 Great Deals out of 2,131 listings starting at $12,496
2013 Toyota Tacoma For Sale
83 Great Deals out of 2,448 listings starting at $9,500