Oil light coming on when braking.

The engine oil light is coming on when braking, is the below true.

When you take your foot off the throttle and then you apply brakes it could be an oil pressure issue. Whilst you accelerate you are building up speed and at the same time you are building up oil pressure. The moment you take ya foot off the throttle the oil pressure will drop with the revs .
Whilst the car is stationary and the engine running press the brake pedal a few times, is the light still coming on, remember the oil light is a light with a symbol what looks like an oil can, your brake fluid level light is a light with what looks like this (0) with a quotation mark inside the circle.

is the oil pick up at the back of the sump?

could be low oil level and then the oil shifts forward under braking and causes a lack of oil in upper part of engine?

personally, I’d get a pressure gauge on there – it could just be a loose connection somewhere.

does it come on if you brake when statioanry?

other thing to consider is that the brake servo runs off crankcase pressure to a certain extent and as you deplete that it may be causing issues?

Your talking way above my knowledge, it only comes on when braking from mid to high speeds, it does not come on when stationary. i will check the dipstick later when the engine has cooled down.

I’d still check the oil level and colour and no white bits in it (head gasket).

i will check the dipstick later when the engine has cooled down.

Nothing stopping you doing it now – sounds like you don’t check your oil too often (like me 😳 )
I had a car that the oil pressure light would flicker on going around roundabouts – oil was low.

The very first thing I’d do when my oil light came on would be check the dipstick. The engine doesn’t have to be cold – just turn it off and wait a couple of minutes. You can do this by the roadside, and I would – the oil pressure light is not a ‘low oil’ light, it’s a ‘omg I have so little oil I can’t lubricate myself and could be putting tends of thousands of miles worth of wear on myself in a few miles so pull over pronto and give me oil!”

Nothing stopping you doing it now

You need to leave it for half an hour after running before checking, so that the oil can drain back into the sump. You’ll get an artificially low reading otherwise.

(I think)

You need to leave it for half an hour after running before checking, so that the oil can drain back into the sump. You’ll get an artificially low reading otherwise.

THIS

Not sure it takes half an hour to be honest – most of it will be down in a few minutes. You’ll know enough to see if it’s massively low or not which is what we are talking about here.

Air cooled 911’s used to have to be checked with the engine running.

I think a number of yuppies were strangled in the 1980’s due to tie/fan interface issues;

Check oil level after you have left it. on modern low oil/water capacity cars the light shouldnt come on unless there is literally no oil on the dipstick.

When mine flickers during long sweeping fast corners (coming off on curved motorway junctions etc) I know its time to top up. When it stated flcikering when stationary I realised it was the sensor.

You need to leave it for half an hour after running before checking, so that the oil can drain back into the sump. You’ll get an artificially low reading otherwise.

I very much doubt it takes that long to drain back down – it would take a couple of hours to top your engine up otherwise.
Modern oils are fairly thin.

I very much doubt it takes that long to drain back down – it would take a couple of hours to top your engine up otherwise.
Modern oils are fairly thin.

This ^^

wwaswas – Member
I think a number of yuppies were strangled in the 1980’s due to tie/fan interface issues;

😆 :clappyicon:

A flickering oil light on tickover can mean your oil pump is worn, unlikely because it’s the best lubricated part of the engine. It might also mean the spring that presses a small valve to regulate oil pressure in the engine is tired and needs replacing.

Oil At Operating temperature is about the same viscocity as water….

A minute or so is all you need to get a reasonably accurate oil level,
It sounds like yours is low.

Oil pressure warning lights are normally activated at <5-7psi…… by the time the light comes on its already doing damage

Many late model cars actually use quite a lot of oil in normal use, they need to be checked often.

VW actually specify that 600ml per 1000 miles oil consumption is not excessive 😯
So much so, they will even sell you a little bag to fit in your boot and hold the 1Litre top up bottle of oil !!

Its the price you pay I`m afraid for increasing emmissions regulation focusing on “cold start” rather than real world (Driving) emmissions….. oil has to be much thinnner to reduce the parasitic losses and reduce the thermal mass on start up, for faster warm up

derekrides – Member

wwaswas – Member
I think a number of yuppies were strangled in the 1980’s due to tie/fan interface issues;

:clappyicon:

Except the 911 was Drysumped………. and the oil tank was remote from the engine 😉

Does it come on when braking heavily or under normal conditions? Does it come on when you pull away fast?

I repaired a car a while ago where the sensor wire had been catching on something & wore through the outer cable, so it would cause the wire to earth out making the light come on whenever you accelerated or braked hard.

First thing to check is the oil level, as mentioned before

VW actually specify that 600ml per 1000 miles oil consumption is not excessive

No longer. The PD engine on my old B6 Passat burned oil at about that rate but the common-rail diesel on my new B7 Passat hasn’t needed any oil at all from brand new to 7,800 miles today.

I’d be checking the level, sounds like the pickup is being uncovered due to slosh. Whenever that little light is on you really need to imagine your engine screaming at you 🙂 Virtually no engine *should* use significant amounts of oil, it’s a bad sign for seals of all sorts, but some do tend to do so more than others by design. This is something manufacturers are sometimes willing to accept for other gains but you really need to know if it does and check it regularly. They don’t last long with low oil.

globalti – Member

No longer. The PD engine on my old B6 Passat burned oil at about that rate but the common-rail diesel on my new B7 Passat hasn’t needed any oil at all from brand new to 7,800 miles today

I think it depends on specific engines. Some seem to and some don’t.
My 1.9 PD engine uses barely any oil between services. I used to check regularly, but it never really dropped.
It’s now on 180k miles (going in for service & cam belt tomorrow) and I’ve upped the service intervals to 15k miles as it just sits on the A1 at 1750rpm all the time.

A friend had the 2 litre TDI Golf GT as a company car for a couple of years and that used to chug through oil at quite a rate. He kept a litre in the boot at all times to top it up.

To the OP – initial thought would be low oil. If not that, dodgy sensor.

A friend had the 2 litre TDI Golf GT as a company car for a couple of years and that used to chug through oil at quite a rate.

Ours does this.

My mums focus deems to like a bit of oil, our Mazda 323 never seems to use any.
I think the key thing is “excessive” consumption or a change in consumption are the key things.

My 1991 Toyota uses about half a dipstick (about 500ml) in about 4K miles of hard use with very high oil temps, that’s always been the case and it gets an oil change at 4K. The engine has done 160K miles, 30% of those modified to +50% power output.

My 2001 306 HDi never uses a drop.

The 1litre top up bottle in my 1.9 A4 lasts me the 20,000 miles between services. Car now has 180k on it, almost all of them chugging along the a1 at 50-70mph

I wouldn’t even bother checking, if the light came on I’d stick a litre in straightaway.

Bad move, Brassneck.
Overfilling can kill too.

I can’t bear the tension, how long can it take to check the oil level in one car!

I wouldn’t even bother checking, if the light came on I’d stick a litre in straightaway.

That would be a mistake also.

I can’t believe people get to own cars without any idea of how they work, how to maintain them and basic things not to do.

Has he done it yet?

This thread is gripping!

On a side note, I used to own an Omega MV6 that would go through a litre of oil in a few thousand miles. No leaks, no blue smoke, it would just go somewhere magically. Then it would throw up a “catastrophic oil level warning” message, that meant that it had dropped to fractionally below minimum.

Add 1 litre of oil, job done.

when was oil changed last, might be old and contaminated and need a change with filter of coarse

Wow! 32 replies! You may all sleep easy, I took the S3 back to Vindis Huntingdon and traded it in for an A1, so it is now their problem. The car was too big and powerful for my needs anyway!

got to love the way the oil light is coming on and first stop is not the dipstick but STW 🙂 i am grinning from ear to ear

cant wait for park two where it takes ages to get the oil in the tiny little hole where the dipstick was 🙂

inline engines esp 4cylinders the oil drains back very quickly, if engine is warm 5 mins is enough to get a reliable reading.
if a v-engine with VVT and complex oil routing / turbos it can take upto 30mins for even hot oil to get back to the sump..
Both physical factors from test / calibration of engine management oil level sensing systems on modern engines.
Sports cars with low sump pans even worse as height variance on dipstick equates to an larger volume of oil thats missing..

As for the original quote re oil light and braking / accel, sump baffle design is pretty well understood these days and your oil level would have to be super low to be missing the pickup..
if the flicker was due to tip out the light would be on at cold start when idling..

either your super low on oil or oil pump incapable of building pressure / pressure is being lost..or wrong oil type in engine..
most engines by the time the lamp is on youve already caused serious damage.
check oil level. top up.
if still flickers.
replace oil n filter.
if still flickers.
check elect connector on oil press sensor for open ciruit / poor contact / short to engine block (will be a simple switch unless modern engine with VVT).
if still flicker replace switch (VW’s fail such that oil leaks through sensor body causing loss of oil and pressure fault but no engine damage)
all the above DIYable with Haynes manual and handtools (for anyone that fixes own bike).
If non of that has fixed it your looking at garage time, get them to check pressure in oil system, should be able to either remove oil press sensor and fit gauge or tap into a port on filter body, from that point your looking at time to take sump off replace pump if failling (unlikely), more likely would be high miles engine thats been poorly maintained and is loosing oil pressure due to wear and tear.
HTH..

I took the S3 back to Vindis Huntingdon and traded it in for an A1

😯

will you do the same when the low fuel warning light comes on with the new one 😉

A friend had the 2 litre TDI Golf GT as a company car for a couple of years and that used to chug through oil at quite a rate.

Ours does this.

On my 4th now and only 2 have needed a top up between there service and then only 1/2 litre each. The current once had done 15k between it’s service before it needed any.

the mrs has a 1.4golf and it uses a bit of oil over the last 10k perhaps 500-800ml

my van doesnt use a drop between services.

My dads company brand new fleet vectra 1.9CDTI went from fine to off the bottom of the dipstick scale within a few days of delivery before the oil light came on ….. vauxhall were instructed to take it away…..youd be even more raging if it was your own car paid for with your own cash !

one thing i notice is my friends think an mot is maintainance – they say oh well it passed its mot its fine. when you ask some of them when it was last serviced they shrug. – thatll be why your 1.4 SRI corsa sounds like a 1litre 3cyl

I can’t bear the tension, how long can it take to check the oil level in one car!

He’s still waiting for the oil to drain back to the sump!