I've got a 05 tacoma that only blows cold air at idle. Once I start down the road it blows heat. The engine temp gauge is holding steady and normal. I haven't tried any fixes yet as I'm not sure where to start. I looked around on the net and found other people having the same issue but no solutions. One guy even said it happened to him right after he bought his truck. Any help would be much appreciated

Might be a flow issue. As the water pump impeller corrodes, it requires more RPM to provide flow. Check for flow thru the cap at idle hot. Will it overheat at idle? Sometimes this is a symptom also. Good Luck.

My first check would be a stuck open thermostat. Replace it and see what happens.

Wish I knew the answer to this issue! I know someone with the exact same problem.

It's a 2009 tacoma 2wheel drive.. The smaller tacoma with 4 cylinder engine. If I find anything, I'll let you know too.

what about a bad heater hose?

or clogged heater (when was the last time you flushed the system?)
i have seen post of gummed up heater hoses/core

Doesn't overheat at all. Temp stays consistant at all times. I haven't tried anything yet. I wanted to see if anyone could give me a starting point. If not i'll start at the cheap end and work up. Lol. Picjon, if I figure it out i'll let ya know

Doesn't overheat at all. Temp stays consistant at all times. I haven't tried anything yet. I wanted to see if anyone could give me a starting point. If not i'll start at the cheap end and work up. Lol. Picjon, if I figure it out i'll let ya know

The problem with the Tacoma I messed with, was NO HEAT at all.. Driving or idling. If the blower was on.. It would be cold. If you drove the truck for 5 minutes at operating temperature, it would blow somewhat warm for a few minutes.

Fixed it this afternoon.. The heater core was definitely clogged.. When I touched the heater hoses going into the heater core.. The upper hose was hot and the lower was hardly warm. I checked them with a temperature gun. The upper has was 150-160 degrees F. The lower was anywhere from 95-110.

If I would keep the rpm's at 2000 for a minute or more, with the blower motor OFF.. The lower heater hose would slowly increase in temperature 125-135 F. This led me to believe the heater core was NOT allowing coolant to pass at a decent rate.

Here's what I did..

1. Removed both hoses from the heater core lines protruding from the firewall to the left of the brake booster, just above and behind the intake manifold..
2. Applied low amount of compressed air to the upper line with an adjustable blow gun. At First, no coolant came out. So I stopped. Turned up the air flow a bit.. and 15-20 seconds later coolant came gushing out of the heater core's lower line.
3. Sprayed large amounts of parts cleaner into the heater core and blew it out for a minute.
4. Reinstalled heater hoses and refilled with Toyota pink coolant.

So now.. Everything is peachy! The heater works great at idle and while driving. BOTH heater hoses are hot at idle, even with the blower turned on.

Hope this gives you a starting point!!! Let your truck warm up.. Then feel the heater hoses.. If they are at similar temperature.. Turn your blower on the 2nd setting and make sure the outlet hose stays warm. If the hose cools off TOO much and the other hose is Way hotter.. You may have an issue with the heater core.

pic_jon

Glad you resolve the heater issue.

Is it still under warranty?

What was clogged in the heater core?