If the oil level in the engine is above/below normal
The lubrication system is designed to reduce friction between the rubbing parts of the engine. In addition to performing its basic function, the lubrication system provides cooling of engine parts, removal of carbon and wear products, protection of engine parts against corrosion. Therefore, malfunctions in the engine lubrication system are very dangerous. We will talk about what to do if the oil level in the engine was above or below the normal level and what the consequences may be.
If the oil level in the engine is below normal
It happens that the oil level in the engine crankcase is below normal. You can check this with a dipstick not earlier than 5-7 minutes after stopping the engine. The oil level is normal if the oil trace on the dipstick is in the middle between the min and max marks.
If the check shows that the oil level is below normal, add oil to the engine crankcase to the required level, preliminarily identify and eliminate possible leaks in the engine lubrication system connections. External inspection of the engine can verify whether there are oil leaks from under the gaskets – camshaft drive cover, valve cover, cylinder block, oil filter, as well as from the filler neck plug, through the oil pressure gauge fitting from under the oil separator cover and through the oil dipstick seal.
❗ Even small oil leaks are an indication that the lubrication system is leaking due to damaged gaskets or seals or unreliable fasteners, which is absolutely unacceptable.
If the oil level in the engine is higher than normal
High oil pressure is no better than low oil pressure: the problem is probably the viscosity of the oil used, check the oil viscosity and quality, change the oil if necessary. Higher oil pressure is common when using summer oil in winter at low temperatures.
In the engine lubrication system, the necessary pressure is provided at normal viscosity. Therefore, depending on the season, ambient temperature and dustiness of the area, manufacturers recommend to each engine a certain oil grade, which has a certain viscosity and necessary lubricating properties.
During the operation of the vehicle, the oil is partially liquefied by the part of the gasoline that is not burned by running the engine on an over-rich mixture, or sometimes because the coolant gets into the oil if the cylinder-head gasket is damaged. Of course, the oil quality decreases, its viscosity decreases if the oil is old and needs to be replaced a long time ago. The oil pressure in the lube system drops drastically, because the low viscosity oil has no trouble penetrating the gaps between the mating rubbing parts.
To ensure long engine oil life with the proper viscosity and quality I recommend that you regularly monitor the crankcase ventilation system and have it cleaned and flushed in good time.
If you fill your engine with oil above the level
There are situations when the oil level in the engine during the next oil change is too high, and most often it is due to inattention. What happens if you pour oil into the engine above the norm? Is it worth to drain it? If you have poured oil a little above the “max” level on the oil dipstick it is no big deal. During the operation the oil will go away naturally and after a few thousand kilometers the oil level will be normal.
If you have poured too much oil above the norm, problems may arise. Especially if you have an old car. When the oil level is higher than normal, the lubricating system will create high pressure, and this can cause deterioration of seals, and then they can “squeeze out”.
It is desirable not to exceed the recommended oil level. If there is a considerable quantity of “superfluous” oil in the engine, it is desirable to drain it up to the norm.
Consequences of oil overflow in the car engine
Any mechanic with experience will list you at least a dozen customers who have been concerned about over-lubrication in the engine crankcase. The story usually begins with someone pouring oil to the standard, but on the dipstick it was 2-3 levels higher. Feeling something wrong, a question follows, and is it not terrible? But owners of used cars ask it seldom, as the car suddenly begins to smoke. And then a number of other statements follow with questioning intonation: how to pour out the excess, and is it not time to raskossoed the inner rings without dismantling the engine, or to change them completely.
Is the maximum really exceeded?
Before diagnosing oil overflow and estimating its consequences for the engine, make sure that the measurements are correct once again. The point of the recommendation is not to pull the dipstick once more. The basic idea is to check how the car is parked and read the appropriate section of the instruction manual.
Only a narrow range of conditions under which the measurement is made is acceptable:
- Under the wheels – level ground.
- Tire pressure is the same.
- Vehicle load level – empty.
What is particularly important is the prescription of the manual about at what engine temperature to measure. How weighty this fact is, judge for yourself – the lubricating fluid expands when heated, and it is already another volume and a different length of the oil trace on the dipstick. Usually, the manual gives a green signal in 5-10 minutes after stopping of completely warmed up engine. However, some automakers allow trusting the control marks only on cold. And in such cars, a level above “FULL” when the engine is hot is absolutely normal.
Warning! If overflow is suddenly detected on a diesel engine + the car is actively eating fuel – urgently go to the highway and burn through the particulate filter naturally. The level has risen due to fuel entering the crankcase of the motor through the oil rings. This is the result of a large number of unsuccessful attempts at active regeneration that the ECU ran the day before.
If, however, all requirements are met and the oil trace is above the maximum, then we have an overshoot. There is nothing good in it.
What will happen, if you overfill the engine oil above the upper level
How bad things are depends on the volume of the overflow. Agree, the difference between 200 grams and 1 liter is significant.
A little extra grease in the engine: are the consequences noticeable
A little is anything above the MAX mark within 1 cm. The same extra 5 mm will not do much harm. Subjectively, of course, you can complain about deterioration of dynamics, but there is only one reason for such a complaint – self-humiliation, no more than that.
What will be really noticeable is the increased appetite for oil. An extra centimeter will go away within the limits of the first 1,000 km. The negative will appear in the form of extra grease on collecting rings, soot on combustion chamber walls and soot in the catalyst.
You can make sure of it, having unscrewed spark plugs from cylinders – electrodes would be greasy for sure. Motors, which are nothing to overhaul, will also smoke (black smoke from the exhaust).
If you regularly pour a lot of oil, after a while there will be interest in how to flush the engine from soot inside and how to do it without disassembly. Soon there will be questions about exhaust: how to replace the clogged catalytic converter and how to cheat the lambda probe.
What is the threat of impressive overfilling?
Anything above the “FULL” mark + 1 cm is considered a critical overflow, and here is why:
- A significant excess of fluid will cause the crankshaft to dip its counterweights in it, resulting in foaming, which is not good. For the oil pump, it’s cavitation with its erosive effects on parts, for the semi-automatic timing mechanism, it’s what makes the hydro-compensators knock when cold and when hot, and for the oil itself, it’s the incomprehensible behavior of the additives.
- The excess is sure to be thrown out to the intake through crankcase gas recirculation, which is also not good. The intake manifold will be doused with oil droplets from the inside, the throttle assembly will get dirty, and the rod and disc of each valve will get covered with malignant deposits.
- The oil seals will leak. They are not designed to bathe in oil. Their function is to repel splatter.
For the record. Rubber bands do not squeeze out from overfilling. It happens because of an increase in crankcase gas pressure. And this is caused by completely different problems: a clogged vent pipe or problems with an oil separator.
How to remove excess oil from the engine if you’ve already overdrawn it
If you change the lube at service station and you find the overflow there, don’t prove to the oilmen the danger of the level being higher than the maximum. Demand to pour out the excess at once, irrespective of their point of view.
And what actually to do when the work was done with your own hands? Certainly not to unscrew the drain plug! Inexperience, 90% will pour out more than necessary.
Actually there are only two working technologies, how to pour out the oil if you have overdrawn it:
- Pump the fluid out through the hole under the oil dipstick. To do this you will need medical accessories: a syringe of any cubic capacity (it is better to take 20 ml) and a tube from a dropper.
- Drain the residue from the oil filter. It fills again with grease only when the engine is running, so you can repeat in several stages, without screwing the filter to the stop in the intermediate operations.
How not to overfill the engine oil at its next change
Why do we get the oil level above the maximum by the dipstick? There are several reasons:
- Carelessness. You missed the moment when it is necessary to remove the canister from the oil-filler neck – get the excess.
- Inexperience. Any automobile engine has a non-flowing residue. Even after warming up, its volume comes to 0.5 liter. If you do not take it into account and pour it in according to the instructions, you will receive much grease.
- Intentionality. When the engine eats oil, it does not mean that you should pour in a reserve. Firstly, it is money for a wind – the expense of grease will only increase, and secondly, the power unit acquires a bouquet of the consequences connected with the increased level of lubrication.
In order not to overfill the oil in the engine, observe a number of simple rules: