Engine Oil Light Again!

SeagullFTB

Hi,

I'm just looking for a quick bit of advice from someone that knows about cars, before paying for a mechanic's opinion. It's our first car, so we certainly aren't experts in car maintenance.

We have a 2017 Kia Sportage with a petrol engine. It's got around 65,000 miles on the clock. The car runs smoothly and it passed it's MOT in April without any issues.

The engine oil level light came on some time ago and we topped it up with about 1.5L of oil. At the start of October, the light came back on again and we put in another litre or so. Now, 10-11 weeks later, the light has come on yet again. I don't know the exact figure, but the car has probably done 1200-1500 miles in that time. Is this normal or is the engine oil dropping too quickly?

There's no sign of oil leaking under the car. Nor is there any white muck around the engine cap.

We can't put much more than 1.5L in at a time, as this takes it to near the Full line on the dipstick.

Just wanted piece of mind that this is normal or if we need to get it checked properly. I've asked some friends and family and they say that their oil is only topped up at the annual service, but they all drive newer diesel vehicles, so it may not be comparable.

Thanks

molerat

The vast majority of cars do not use any oil, some VWs were renowned for 1l/1000m but that was an exception.  You should be checking the oil weekly - it is one of the routine checks you should be doing, not waiting for the light to come on - and if there is no sign of a leak then the engine could be burning it.  Is the exhaust pipe oily at all ?  Any smoke when you floor it or when you take your foot off the pedal ?

SeagullFTB

molerat said:

The vast majority of cars do not use any oil, some VWs were renowned for 1l/1000m but that was an exception.  You should be checking the oil weekly - it is one of the routine checks you should be doing, not waiting for the light to come on - and if there is no sign of a leak then the engine could be burning it.  Is the exhaust pipe oily at all ?  Any smoke when you floor it or when you take your foot off the pedal ?

The exhaust pipe isn't oily and there isn't any smoke when driving. No burning smells either.

I plan to top up the oil and note down the mileage. And then monitor the level and mileage on a weekly basis for a few weeks.

Kia seems to suggest than using 1 quart every 1000 miles is "normal" on a car with over 50,000 miles on the clock.

EssexExile

For something like this I'd suggest looking at the Kia owners club forum.

Mildly_Miffed

Even if this "oil light" is explicitly a LEVEL warning, not the PRESSURE warning that's ubiquitous, leaving it until it's low enough to warn is not a good plan.

If it is, as I suspect, a pressure light then the only reason it would come on because of low level is that the level is SO low that the oil pump is sucking air up instead of oil. And that's the best possible way to kill your engine.

Check it regularly! Same time as you check your lights, tyres, coolant, etc... You DO do that, right?

SeagullFTB

Mildly_Miffed said:

Even if this "oil light" is explicitly a LEVEL warning, not the PRESSURE warning that's ubiquitous, leaving it until it's low enough to warn is not a good plan.

If it is, as I suspect, a pressure light then the only reason it would come on because of low level is that the level is SO low that the oil pump is sucking air up instead of oil. And that's the best possible way to kill your engine.

Check it regularly! Same time as you check your lights, tyres, coolant, etc... You DO do that, right?

It's definitely a LEVEL warning, not a PRESSURE warning. They are two different symbols and two different colours.

I check the oil every 2 weeks or so. It was above the minimum line last time I checked. The warning light seems to come on as soon as the oil level hits the minimum line.

kinger101

That is a lot of oil that must be going somewhere. I'd get it checked out at a garage.

Putting too much in can cause excess pressure leading to leaking gaskets. Is if possible you iverfilled the first time

Goudy

These engines are fairly notorious for using oil.
Just try Googling Kia GDi Carbon build up.

I believe later engines are better but the direct injection system they used causes carbon issues with the valves and piston rings over time/mileage.

As petrol is injected directly into the combustion chambers no petrol passes the valves (petrol works as a solvent), there is only air and oily crankcase vapour passing the intake valves which tends build up and bake on to form lots of carbon.

I seem to think later engines, the Smartstream engines had a secondary injection port (a split port) which sent a small amount of fuel over the valves to help clean them.

All this carbon leads to poor combustion due to the carboned up valves as it reduces compression, which leads to more carbon.
This carbon is just a by product of fuel that hasn't burnt completely and it starts clogging up the piston rings.

These gummed up piston rings lead to more loss compression, so more and more carbon.
Now oil can pass the rings into the combustion chambers, hence it using oil.

This oil in the combustion chambers leads to even more carbon as it fails to burn completely and now you have a problem that is snowballing very quickly.

First point of call would be a compression test of all the cylinders but dealers in the past when presented with this problem required owners to do an oil consumption test to try and work out how bad it is.

A litre every 1000 miles isn't great.
You won't really notice blue smoke in the exhaust gas, it's only using a tiny amount of oil in each cylinder on each combustion stroke, but over time/miles it all adds up to a big loss.
If it was using lots of oil in a shorter space of time then yes, blue smoke would be expected.

If it is this problem the fix isn't easy.
Some owners have improved the problem by using various solvents designed to dissolve some of the carbon, but results aren't always good am I afraid.
If compression is down you might want to think about another option, like getting rid now before it gets worse, otherwise you need to start to disassemble the engine to get at the carbon.

SeagullFTB

Thanks @Goudy for the detailed response.

I've put 1 litre of oil in, which has taken it to just below the maximum line. I've recorded the mileage. I'm now going to record the level and mileage every week, to monitor the consumption. If it appears to be dropping quickly, I'll book in a compression test.

Goudy

SeagullFTB said:

 If it appears to be dropping quickly, I'll book in a compression test.

Either that or a leak down test.
A leak down test would give a better indication of what is going on in there.