Looking for the thermostat I found a weird piece on top of engine called a coolant outlet housing, has a bleeder valve on top. Its as if the compressor only work after the car is driving for a few minutes. It blows cold air when at a stop light or at low speeds. to fix it go the the auto parts store and get a piece of rubber tubing and put the two piece's back together.. Coolant level is good. It blows cold air when at a stop light or at low speeds. it's just weird that as long as i'm at atleast 2-3k, it blows hot air but when i'm idling (~850rpm), its just normal air. Tags: Cold Air, Hot Air. My heater only blows out hot air if i am driving. I was told that I need replace exhaust manifold gasket because of oil leak, no o. Or blow them out with a compressor maybe? Low Refrigerant Levels. When your car is moving, say at 45 MPH, there is lots of air flow over the condenser (the condenser is the heat exchanger in front of the radiator) and that airflow is essential to proper a/c system operation. By using this site, you agree to these terms: What's the best way to remove water in my gas tank? yeah i'm doubting t-stat for those reasons as well. Using a test thermometer, check the temperature of the air being discharged at the HVAC housing floor outlets. The condenser is located near your radiator and looks like a smaller version of the radiator, with loops of coils and fins that disperse heat and allow the refrigerant to return to a liquid state. Temp stays normal. Or is it more likely to be a blocked heater core, or bad thermostat? Looking for the thermostat I found a weird piece on top of engine called a coolant outlet housing, has a bleeder valve on top. Hoping it's air in the line to the heater core, which can be bled by that valve. Both systems include a compressor, condenser, evaporator, and receiver/drier. Recently had the fan clutch, water pump and thermostat and belt changed. Temp gauge looks normal, and heat blows when car is moving. The temp stays normal in not cold or hot. It's just no money to be made on that job. In most cases, it's due to a loss of refrigerant in the system. what the op described its pretty much exactly what happend to me with my z. i started noticing the heater didn't seem to blow as hot when not moving but thought i was just crazy. Coolant has been a hair low twice in the last few months, but nothing alarming. IMO. No temp/ overheating probs, no strange noises/ leaks, no warning lights. A defective condenser fan. All I have to do to get hot air again is give it a little gas, say 200 more rpms, and the heater immediately responds with warmer air, hot air if I maintain 1000 rpms. Did some research, and I guess these 2.7 L V-6's have all kinds of weird little quirks. If it needs a T-stat, good luck, the local dealer here doesn't even replace them! Air flows fine. Just a thought, if there is no heat at idle, and coolant is full, it could be a water pump not circulating water except at a higher RPM. Check in the recovery bottle and if it has a radiator cap, the radiator. The heating system in your car is supposed to keep the atmosphere warm. How Does Your Car Heater Work? Ever clear a blockage or bubble in the heater core? This vehicle MIGHT have a bleeder for this purpose. Your car AC is actually a heat exchanger that recirculates warm air from inside the cabin and replaces it with cold air. That's when you should bring the vehicle in for diagnosis, rather than continuing to add refrigerant that's just going to quickly leak out again. Your car AC is actually a heat exchanger that recirculates warm air from inside the cabin and replaces it with cold air. What about the water pump? This is the reason that it takes a while for heaters to start blowing warm air. Winter rolls around, and you quickly realize that hot heat in … There could be several reasons behind this problem. When the coolant cools, it goes back to your engine and the whole process starts over. YOU HAVE AN AIR BUBBLE IN THE COOLING SYSTEM!!! The lack of heat being generated by your system may indicate a clogged heater core. No leaks I can find. Since it's right up front with the radiator, it's easy for the condenser to pick up bugs, leaves, plastic bags and other trash and debris from the road. A fan blows over your heater core and directs warm air into the cabin. Checked the actuator and it's working. Any degree of blockage in the system can lead to the condenser not being able to execute its … Your refrigerator, however, isn't subjected to the extremes of heat and vibration that go on under a car hood. What happens is this: Refrigerant that's in a liquid state makes its way to the evaporator, where it "boils" as warm air from the cabin flows across it. Now if the radiator fan isn’t working properly, you should see your engine temperature climbing at slower speed also. You don’t pay it too much attention because it’s summer and you enjoy the convenience of the burst of cool air. As soon as I stop at a red light, or am idling for any length of time the air coming out of the vents begins to lose temperature until it blows cool air. Both hoses to heater core are warm. I have checked the coolant level and is normal. I did ONE, and that's it for me!! The fans could actually be broken, like a burnt out motor, bad mount a chipped fan blade, or they could simply have an electrical problem like a blown fuse or burnt out relay. The AC on my 2008 2.0 L turbo now only works when I am driving at speeds of at least 30 MPH. The cooling fan in the condenser is the first thing that you should look into while finding out the reason for car air conditioner not blowing cold air when idling. What is wrong with it? The most common reasons that AC blows warm air in car are leaks in the air cooling system, broken compressor, worn-out clutch or electrical wiring problems. But if you’re a DIYer, you may not prefer it. When driving at slower speeds or idling, the AC blows warm air. Each of these problems has its own level of gravity thus different costs of repairing. The flow of water through the heater core is hindered by a pocket of air. If your car AC blows cold air when driving at highway speeds but turns warm at stop lights or when driving at slow speeds, you may have a bad radiator fan or radiator fan relay. Recheck the coolant level, again. 1. Once the engine has warmed to operating temperature, and I am driving it around, the heater works great. Many cars are equipped with two radiator fans, while others have one fan that can run at different speeds. When driving at slower speeds or idling, the AC blows warm air. I know this is not a good engine for turbo but I might Jerry Renshaw is a veteran journalist, gearhead and guitar player, and cultivated his mechanical skills by 30 years of turning wrenches to keep one piece of junk or another on the road. Think there might be a crack in the gasket, or the sleeve the actual valve is in because when I try and turn it, the whole thing spins. Or worse yet, you come out to start the car one day, turn on the AC and it's blowing barely cold air when it was fine just yesterday. What could the problem be? Hey guys, 2011 Xterra with 85k on it. Anyone know why the heater only works when the car is moving? Car AC designs are far more robust than they once were, but even a late-model vehicle can lose as much as 10 percent of its refrigerant over a year's time. Is the engine getting hot with extended idle, temp going up? Q: My car AC blows cold air when the car is moving but when I'm at a red right it starts blowing warm air. A defective condenser fan. It likely means that a line or seal or O-ring has given up, or you possibly have a switch or other circuit that has failed. Here's Your Basic Car Maintenance Schedule, Diagnostic Tips When Air Conditioning Isn’t Working, Common A/C and Fuel Efficiency Myths Debunked. Its cold out. My slowly deteriorating 95 BMW 325i has been having some AC/heater problems lately. What happened? I'm not getting heat when the heater is engaged. 2012 Jeep liberty blowing cold air as well as heater when heater is turned on 3 Answers. then it got to the point where it wasn't blowing hot air at all when at idle (i was out of town for work so i didn't have time to take it in). Here is a video on how to recharge your vehicle's Air Conditioning with A/C Pro: If it's sudden as in one day it's working fine and the next day it isn't—that's a problem. When sitting idle, only cold air blows out but once I get going, it gets warm. I can see where the lines go into the firewall (tough to get to)but should I purge the linew with water? In most cases, it's due to a loss of refrigerant in the system. I have checked the coolant level and is normal. Dysfunctional Thermostat. My car heater works when I'm driving but not when I'm in idle. I would pull the two heater core hoses off the back of the head and try flushing the heater core out by … All I have to do to get hot air again is give it a little gas, say 200 more rpms, and the heater immediately responds with warmer air, hot air if I maintain 1000 rpms. It blows warm air when RPM's get around 2K or higher. Note Low … It may take a few Min's to find just keep looking. If you car heater starts blowing cool or cold air when you drive you car on the highway in cold weather this is a sign that you might have a bad thermostat. With the engine idling at normal operating temperature, set the temperature control knob in the full hot position, the mode control switch knob in the floor heat position, and the blower motor switch knob in the highest speed position. There is coolant and before I had to refill my coolant every 2 to 3 days but it’s been full for the past 5 days. It's easy after you get the plenum unbolted and raised to access the back bolt. Is there an esy way to test the water pump? but if I just stay in the drive way with the engine on the air will only blow hot air. Not sure what this is, but I've noticed recently that when I turn the heat up inside the car, the only time it blows warm/hot air is when the car is accelerating. The cooling fan in the condenser is the first thing that you should look … Both systems circulate refrigerant through a closed circuit, compressing it to a liquid state and then evaporating it to provide cooling. Tried to bleed air from coolant/ heater core lines, but the valve just spins in its fitting. Never seen an assembly like that, though. At first I thought it was just slow to warm, but yesterday I let it run for 20 minutes and it was still blowing ice cold air when I got in. It could be a faulty radiator cap or it could mean there’s a leak somewhere in the system. Car Blows Cold Air When Stopped, But Blows Hot Air While Driving. I brought car to two VW dealerships to have their service department diagnose the problem. If I stop at a light it gets cold again. Despite its chilly name, coolant actually works hard to heat up your vehicle during … My car has an automatic transmission. Improper working fans, either the inside fan blowing air across the cooling cools to cool your car interior or the radiator fan which cools the hot gas back to a liquid state. Could be water pump. And that thermostat is a HUGE pain to get to. The refrigerant near the exit of the evaporator is superheated, but the moisture in the refrigerant entering this component starts to form ice crystals, freezing up the system. In most cases, it's due to a loss of refrigerant in the system. Coolant level is good. This can be so annoying only hearing that fan blow it’s air all over you when it is not needed. Either way, you don’t want to drive around with a vehicle that is leaking coolant. I usually have to keep the RPMs up to keep it blowing hot. The most common cause of hot air coming from car AC vents is low levels … You're right about the t-stat. It means that the refrigerant loss has been gradual, over a period of months, and that's fairly normal. I want the air to blow hot when stopped.