Checking the oil level of an automatic gearbox and power assisted steering
An automatic gearbox is a complex hydraulic system transmitting the engine power to the wheels, mainly by the oil it contains. Its quality and performances are therefore essential to ensure perfect operation, whatever the conditions, and also to promote longevity of the gearbox, a particularly expensive car part.
These lubricants are specific and can in no case be replaced by engine or manual gearbox oil. It should also be borne in mind that drain operations (every 20 to 60,000 km depending on the vehicle) require a minimum of knowledge and tools. It is therefore preferable to entrust this operation to a professional to avoid doing anything wrong. On the other hand, checking the level of an automatic gearbox is a simple operation to be made every 10,000 km. Refer to your car's manual for details on this operation. As a general rule, you must turn the engine on and place the speed selector at position 'P'.
Oil temperature also influences the level, so as a general rule you must carry out this check on a hot engine after it's been running for at least 10 minutes. For a precise check, first wipe the dipstick with a lint-free cloth, and also take care not to introduce any dirt into the hole.
If the level is insufficient, pour some Dexron Motul down the dipstick hole. Take care: a few millilitres is enough as a complement, as the total content of the gearbox is generally low.
High consumption of gearbox oil is abnormal. A level that has dropped is generally caused by a leak, which you must repair as soon as possible.
Power assisted steering
The power assisted steering of cars is generally hydraulic and requires, like automatic gearboxes, Dexron fluid, to operate correctly. This oil is therefore the same as that of automatic gearboxes but the two circuits are clearly separate.
The hydraulic system of power assisted steering comprises a little reservoir in the engine compartment. It is translucent with marks showing the levels or it has a dipstick incorporated in the cap. To check the level, the engine must be turned off
All you need to know on cooling liquids
Your car engine automatically has a cooling system providing it with an ideal and constant running temperature, whatever the season. Liquid cooling systems, far more modern and effective, have become the rule in cars, superseding 'air' systems, which are still used in small-to-medium capacity motorcycles.
Motul sells three ready-to-use liquids meeting all the specific characteristics of different cooling circuits. These products have three essential qualities: they ensure effective heat exchange while avoiding boiling, protect all the circuit internal elements (pump, radiator and engine) against corrosion, and guarantee strong resistance against frost, even at the lowest temperatures.
For all these reasons, the use of pure water is proscribed and could cause irreparable damage to the mechanical parts. The products GL 25, and INUGEL type D have freezing points under -25°C. For even more extreme conditions, INUGEL 50 pushes back this limit to -35°C.
All these products meet the AFNOR standard 15-601, INUGEL type D having been specifically developed and approved by Renault for its 'Type D' specifications and not being compatible with the other products.
Now you know everything about cooling liquid, don't forget to have it drained every two years on average so that it always provides the best performances. Between these drains, if it changes colour and become brownish you should also replace it. In all cases, check the cooling liquid tank level and make it up if necessary. Do this operation with a cold engine and comply with the 'min' and 'max' marks. Do not unscrew the radiator cap if it has one: modern circuits are generally pressurised and require precise tools and a precise protocol for any intervention. Last, cooling liquid also feeds the passenger compartment heating system.
Easily check your oil level between two drains
All cars, whether a large sedan, racy sports car, or little city car, require well lubricated mechanical parts. Engine longevity is ensured, inter alia, by oil, provided this oil has very good performances and provided it fills the sump to capacity. For the first point, you can trust the entire range of Motul engine oils, but the second point requires you to check the level yourself, using the dipstick.
With today's lubricants and new engines, it's sufficient to carry out this operation once every two thousand kilometres. On the other hand, for 'older' engines, this check should be made more often, approximately every thousand kilometres.
To make a precise check of the oil level, wait till the engine is sufficiently warm (after running for 15 minutes) place your car on a level surface and switch off the ignition. Open the bonnet, pull the dipstick out (generally identifiable by a yellow, blue or red mark, depending on the make of car) and wipe it with a clean cloth.
Reinsert the dipstick as far as it will go, wait for a few seconds before removing it again, and take the oil level reading. The oil should be between the two marks on the end of the stick, but in no case should be above or under. Too low a level of oil could cause serious engine damage for want of lubrication.
If the oil level is close to 'min' you should add some after unscrewing the big cap generally located on top of the engine. If access is awkward, use a funnel to avoid spillage and, above all, ensure no foreign body enters the engine. All Motul packagings have the advantage of having a pull-out spout for quick and spill-free filling. They also have a graduated scale so you can add just the right volume of oil. The difference between the 'min' and 'max' marks varies by half a litre in small cars to several litres in high cubic capacity cars. Generally the car's manual mentions this characteristic.
In all cases, add only a moderate complement and wait for several minutes for the oil to descend into the sump before checking the level again and adding more oil if necessary. Do not try to reach the maximum level. You could end up adding too much oil, which would cause excessive pressure damaging the lubrication circuit. Last, never place blind faith in the dashboard oil warning light: it generally indicates oil pressure and not the quantity of oil in the sump. In all cases, if this light comes on, even if only flickering, stop immediately and check the oil level.
Specific case of 'dry sump' engines
Some sports and prestige cars have an engine lubricated by a dry sump. Oil is then located in a large-quantity reservoir (more than ten litres) outside the engine. To check the level here, the engine absolutely must be running and you must follow the precise protocol for each car.