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Weird Heat

Hi guys, This is George form Chantilly, VA
I’m not sure if such a question should refer to you and your show, but will give it a try. OK, little pre-history:
Few weeks ago the heat in my car (Toyota RAV4 '03) refused to work. I went to the mechanic shop with an attitude to have a repair for about $500. After a diagnose for $100 the guy told me I need new head gasket, so he rounded to 2K. It was such an electric shock, however after 2 weeks I walked back to the same shop ready for execution. They got the car and next day called me with a news that the car need a new engine, because they stretch few of the bolts. So far so good. I found almost new engine and everything was done in a few days. Couple of days later when I turned the heat I observed something really interesting (read - weird). OK here is the question:
The heat works. The problem is that the left part of the system blows cold, the right blows hot. To illustrate this: imagine four air windows - the very left blow cold, the middle left - warm, the middle right - warmer, the very right - hot. Not sure what is this and before I go back to these guys I like some opinion different than their. I’d really appreciate if you help with advise.
Thank you

Wait a minute. The car needed a new engine because they stretched a few of the bolts? Huh? Tell us more about that. Did they charge you for the engine?

Which vents are you feeling? The top vents or the floor vents? How exactly do you have the controls for the heater set?

Well they ask me if I authorize them to buy the engine and off course their price for engine with 100k miles on it was around over 2600. Well I’m not very good with mechanics, I have to admit.
Now, all vents work properly, in sense they blow air, but the left side, including windshield and lower vents are blowing cold air. At the same time the right side blows hot air. Absolutely doesn’t make sense. I don’t know!!! Any idea.

The heater is controlled in a simple way, face vents, face and legs, window and legs, window. Up and down doesn’t make any difference, left and right does.

If you are getting heat at all, then the passenger compartment heat exchanger must be working and the thermostat in the engine compartment must be working too. So the lack of heat from one side of the vents must be one of the venting doors under the dashboard that route the heated air around (to the floor vents, to the dash vents, to the windshield, etc per the heat setting) is not working. You can poke your head around down there to see if there’s anything unusual, like leaves in the way, but you’ll probably need someone with expertise on your make/model/year to help you with this.

@GeorgeSanJose,
Thakns George, I was thinking about leaves and that kind stuff in the way, but there is an air, only the thing is that this air is cold. Could it be a broken wire or fuse?

It’s possible, sure, but no, I don’t think from your description a broken wire or fuse is the problem. There’s something wrong with the airflow. Something is blocking it from flowing correctly through the venting system.

If you have doubts about the heater core function, one test that is pretty easy to do is to ask your mechanic to compare the temperature of the heater hoses that enter and leave the heater core. These are usually accessible from the engine compartment where they go through the firewall. When the heater is on “hot”, the hose entering should be hot, and the hose leaving should be noticeably cooler, and the difference should be more when the heater fan is on high compared to low.

If the right side is blowing hot, the heater core is working. The problem is the door(s) in the ductwork that direct the air.

Like Shadow, I too question tghe work. But it’s done now. Time to put it in the past and focus on the vent problem.