Cold stove at idle

Cold stove at idle speed can be for the following reasons - a low level of coolant in the expansion tank, the formation of an air lock in the cooling system of the internal combustion engine and / or stove, a faulty water pump, a clogged radiator, and some others. In most cases, a car enthusiast can independently get rid of the problem when the stove blows cold at idle. To do this, you need to check the cooling system, or rather the operation of some of its elements.

Why does the stove blow cold at idle

The essence of the reason why a cold stove at idle in most cases comes down to problems with the internal combustion engine cooling system. So, there are FIVE basic reasons for this situation and also a few less common ones:

• Insufficient coolant level in the system. This is the most common and easiest option to fix. In such a situation, even significantly heated coolant is not able to sufficiently warm up the interior heater. Please note that a low level of antifreeze in the internal combustion engine cooling system not only causes the heater to blow cold air at idle, but also harms the engine itself, as overheating occurs, which leads to a decrease in its overall service life. This problem is an indicator of the failure of its individual parts, or a change in their geometry.
• Air congestion. Air in the cooling system may appear due to depressurization of individual pipes or their connection points, incorrect replacement of the coolant, air valve failure, problems in the operation of the pump, or a breakdown of the cylinder head gasket (cylinder head). Air locks impede the circulation of antifreeze in the system, as a result, the stove heats up only when driving, and at idle, cold air blows from the deflectors.
• Faulty water pump. This unit is responsible for the circulation of fluid through the system and when the impeller is not able to create sufficient flow, the stove blows cold air at idle, and when the car is moving it can be a little warmer.
• Dirty heater core. The heater core tends to clog over time. As a result, heated liquid begins to pass poorly through its cells. And this, in turn, will lead to the fact that the stove fan drives barely warm, or even completely cold air.
• Shut off coolant supply. If the stove has a valve for supplying liquid to the heater radiator, then it may be that the car enthusiast simply forgot to open it, also shutting it off in the summer, or it was jammed in a half-open or fully closed state. This is especially true for domestic cars, especially quite old ones (for example, VAZ “classic”, Muscovites and other cars also of Soviet design). Usually, taps simply rust, especially when instead of factory antifreeze, a car enthusiast uses ordinary water as a coolant, especially “hard”, that is, which contains a significant amount of salts of different metals.
• Failure of the thermostat. When the thermostat rod sticks in the open state, this will be the reason why the stove blows cold at idle. If in a cold internal combustion engine the coolant will initially circulate in a large circle, then it will be able to warm up only after a long time the car is moving, or it will take a lot of time to warm up when the internal combustion engine is idling.
• Problems with the operation of the climate control system. In modern cars equipped with this system, software malfunctions sometimes occur, which leads to a situation that the stove does not heat at idle. Problems can be associated with either incorrect configuration of a particular system, or a software or hardware failure of the climate control.

Breakdown elimination methods

Methods for eliminating the problem of why the stove at idle blows cold air will depend on the very reasons that have been rechecked in order. So, first of all, you need to check the coolant level in the expansion tank. note that this must be done on a cold ICE (!!!), so that the coolant was also relatively cold and the car enthusiast did not get burned.

If it is below the middle, then add coolant. In this case, it is necessary to take into account the compatibility of antifreezes. It is advisable to fill in the same brand and class that is in the cooling system. If the antifreeze has not been changed for a long time and / or is in poor condition, then it is better to replace it with a new one.

If air pockets form in the cooling system, they must be eliminated. There are three basic methods for removing air from the cooling line. All of them boil down to the fact that in order to let the engine run with a depressurized system, so that the air in the process of circulating antifreeze independently leaves the system. you can carry out the procedure for removing air from the cooling system yourself in the garage and even in the field.

When the check showed a breakdown of the pump, then it will have to be changed accordingly. But in order to identify the problem, you will have to dismantle the water pump. Often the cause of the breakdown lies in the wear of the impeller, bearing, depressurization of the seals. As for the bearing and rubber seals, in some cases they are replaced with new elements.

If the reason lies in the difficulty of the passage of liquid through the stove radiator, then you can try to rinse it. At the same time, it will be possible to see if it has cracked the body, and accordingly, if antifreeze is flowing through it and if air is being sucked in. Usually, flushing has a positive effect on the efficiency of the stove, including the idle speed of the internal combustion engine, as well as when the car is driving on the highway or in the urban driving cycle at high speeds.

If the machine stove has a valve for supplying liquid to the radiator, then do not forget to check its operation. So, for example, on VAZs (both new and old), this is one of the weak points of the interior heating system.

When the stove does not heat up well only when starting on a cold engine and at the same time the internal combustion engine itself does not gain operating temperature for a long time, then the first thing to do is to check the operation of the thermostat. So, for the first few minutes, until the coolant has reached an operating temperature of about + 80 ° С ... + 90 ° С, the branch pipe suitable for the top of the main radiator will be cold and relatively soft. The thermostat valve should only open when the antifreeze is warm enough. If yours is different, the thermostat needs to be replaced. In rare cases, you can try to repair it, but it is better to put in a new one.

The car's climate control system operates on the basis of its own separate software and hardware. Therefore, checking its operation depends on the specific brand of car and the type of system itself. The verification algorithm is usually described in the car manual. If such information is available, you can check it yourself. Otherwise, it is better to seek help from a car service, preferably one that specializes in working with a particular brand of the car being checked.

Hack and predictor Aviator

If the stove heats up only when driving, first of all, you need to check the level of antifreeze in the cooling system, as well as its condition. next you need to check the pump, thermostat, radiator, stove tap, the presence of air jams in the system.

If, when the engine is warming up at idle, the stove blows cold for too long, then it is worth insulating the radiator grill with improvised or special means. Be that as it may, remember that a poorly functioning stove. Be that as it may, it indicates problems in the internal combustion engine cooling system, and operating a car with such problems is fraught with costly repairs in the future, so repairs should be carried out as quickly as possible.