How to warm up the variator in winter before a trip and how much time
Content
All types of automatic transmissions require more delicate handling during operation than simple mechanics. But the variator is especially sensitive to this, where a metal type-setting belt sliding along the conical pulleys is used.
The properties of the oil play the most important role here. But they strongly depend on temperature, becoming optimally acceptable only in a rather narrow temperature range.
Both overheating and excessive cooling are dangerous, which is difficult to avoid in winter. It remains only to be careful about preheating.
How does the variator behave in the cold
The oil in the variator performs several important functions:
- creating a control pressure for the operation of cones and other mechanisms with hydraulics;
- ensuring strictly defined friction coefficients in critical pairs, if the lubrication is theoretically ideal, the friction force will be zeroed, and the car will not even be able to move;
- formation of an oil film to prevent wear of parts;
- heat transfer from loaded elements to the surrounding space;
- corrosion protection and many other tasks.
Changes in temperature will affect each of these roles. The complexity of the chemical composition of the product is such that it is no longer even called an oil, it is a special variable speed fluid of the CVT type. Under extreme conditions, it stops working normally.
At high temperatures, oil coolers and heat exchangers are used to bring the situation back to normal, and at low temperatures, preheating is used.
There is no doubt that a working variator will allow movement, even if it is not heated, but there is nothing good in this. It will quickly come to a state of not entirely serviceable, after which it will begin to behave inappropriately to varying degrees, and then finally collapse.
All breakdowns are due to long-term operation, violations of its rules, as a rule, as a result of haste. Both on the road and in preparation for the trip.
In relation to the warm-up regime, several points of violence against oil and mechanisms in winter can be distinguished:
- difficulties with pressure adjustment, the viscosity of the oil is growing, especially if it has not been changed for a long time, and it has lost its quality, even a specially designed valve cannot cope;
- the friction force between the belt and the conical pulleys slowly increases, under load there is slippage and increased wear;
- all parts made of rubber and plastic harden, lose strength and resistance to oil pressure drops.
Obviously, such operation of a cold variator cannot be considered the norm in terms of saving its resource. Repair is very expensive, it is desirable to delay its time as much as possible.
How long does it take for normal operation of CVT
The duration of warm-up depends on the air temperature and the operating mode. Situations can be roughly divided:
- to zero degrees and even slightly lower, special measures are not required, oil and mechanisms will ensure normal operation with their quality, unless you should immediately develop maximum loads after the start;
- from -5 to -15 degrees, preheating is required for about 10 minutes, that is, in parallel with the engine;
- below -15 a lot depends on the warm-up mode, the characteristics of a particular car and the availability of free time, sometimes it is much cheaper to refuse a trip.
Even after preheating, the operation of the box cannot be considered completely normal. It must be loaded gradually, it will enter the mode even later than the engine.
The method of warming up the variator in winter
There are two stages of temperature increase - on the spot and on the go. Warming up to operating temperature without movement is useless and harmful to both the engine and transmission.
It makes sense to heat the liquid, and hence all the mechanisms, on the spot to a temperature of about 10 degrees. That is, a little higher than the threshold beyond which you can generally immediately start moving.
In the parking lot
The variator will warm up without any manipulations with its controls. But it will take about twice as long.
Therefore, it makes sense a minute after starting the engine, turn on reverse for a few seconds, of course, holding the car with the brake, and then move the selector to position "D".
Further, it all depends on the design of a particular transmission. Most allow you to keep the engine idling in Drive mode while holding the brake. Up to 10 minutes or more, depending on the cold.
The torque converter works, intensively mixing and warming up the oil. But if it is absent, then it is better to save the box and warm it in the parking position of the selector. A little longer, but safer.
In move
When the oil temperature has become positive with a small margin, you can start moving. Warming up will immediately accelerate, which will allow you not to waste time and not pollute the atmosphere with unnecessary work at idle.
This will not harm the variator in any way, if you do not abuse the loads, speed and sudden acceleration. The engine and transmission will simultaneously enter the optimal thermal regime. Enough ten kilometers.
What not to do when warming up the CVT
About sharp starts, acceleration, high speeds and full throttle have already been said. But you can add that you should not cyclically repeat the transfer of the selector to different positions, this does not make sense, but only loads the mechatronics and hydraulics.
It is important to use fresh liquid in the box in winter. If the period of its operation is close to the limit, and this is about 30 thousand kilometers for a caring owner, then the oil in the variator must be replaced in anticipation of cold weather.
It is not necessary to spin the engine up to high speeds, even if the box allows it. This also adds safety in terms of the road situation.
If the exit from the parking lot is associated with slipping or breaking through snowdrifts, it is better to wait until guaranteed warming up. That is about twice what is recommended.
Steep climbs to an unheated variator are categorically contraindicated. As well as long descents, where there is a risk of overheating service brakes.
If the temperature is below -25-30 degrees, then it is better not to operate the car with a variator at all. Harm will be done to it even with the most correct warming up. Or you need a warm place to store the car.
