Oil warning light - Page 2

vorsprung durch technik · 21-07-16, 09:33 AM

An oil change for decent quality oil could well make a difference,quality oil is so important imo. On this very subject i've read that sender units play up over time like any electrical items can and do and this could well be your reason for 1bar showing and the alarm going of. Once the oil has been replaced i would replace the oil pressure sender before any other investigations as it's been covered before and replacing the sender did the trick.

HTH.

vorsprung durch technik · 21-07-16, 09:48 AM

Quote:

Originally Posted by Crossle

It's only been an issue in this extreme hot weather and it is running slightly hot so suspect the heat might be causing it

Yep that's normal for the pressure to be lower in extreme hot weather as the oil gets less viscous and thinner the hotter it gets.

As for Bruce and his 3bar .. .. .. that's excellent for his area "Sitting at the bottom of the dark puddle"

but if he lived down here (south with the mediterranean temps) his 3 bar would dissapere rapidly with the extra heat.

Crossle · 21-07-16, 11:00 AM

Quote:

Originally Posted by vorsprung durch technik

Yep that's normal for the pressure to be lower in extreme hot weather as the oil gets less viscous and thinner the hotter it gets.

As for Bruce and his 3bar .. .. .. that's excellent for his area "Sitting at the bottom of the dark puddle"

but if he lived down here (south with the mediterranean temps) his 3 bar would dissapere rapidly with the extra heat.

Shes had a filter and a fresh filling of oil yesterday. Oil was quite dirty actually.

Do you know what sort of Oil Pressure you would expect to be normal for hot idle? I tested it today, pulled up from hot and true to form the pressure dropped to exactly 1 bar and on comes the light, I hung a few RPM on it and bought the pressure up to just above 1 bar and out goes the light. This suggests to me that the warning lights are set to come on at 1 bar. The water temp is running at 3/4 of the way up the gauge and normally Coupes I have had in the past have sat at half way so unsurprisingly for the weather we have had it is running hot I would say.

Basically what I am looking for someone to say is- dont worry its just the hot weather, your engine is not going to blow up lol. I can go back to sleeping at night then!

Sound wise I have never heard such a quiet, smooth Coupe, not even the slightest knock or rattle from the engine hot or cold so hopefully all is ok.

vorsprung durch technik · 21-07-16, 11:19 AM

Quote:

Originally Posted by Crossle

Do you know what sort of Oil Pressure you would expect to be normal for hot idle? I tested it today, pulled up from hot and true to form the pressure dropped to exactly 1 bar and on comes the light, I hung a few RPM on it and bought the pressure up to just above 1 bar and out goes the light. This suggests to me that the warning lights are set to come on at 1 bar. The water temp is running at 3/4 of the way up the gauge and normally Coupes I have had in the past have sat at half way so unsurprisingly for the weather we have had it is running hot I would say.

Basically what I am looking for someone to say is- dont worry its just the hot weather, your engine is not going to blow up lol. I can go back to sleeping at night then!

Sound wise I have never heard such a quiet, smooth Coupe, not even the slightest knock or rattle from the engine hot or cold so hopefully all is ok.

Just quickly checked your profile and i can't make out what engine you have or see a picture of it? 2.3 5CYL 10V OR 2.3 20V?

Over the last 16 years of B4 2.6 ownership i have seen a bit below 2bar in very hot weather in the silver one when the car was only 6 years old which came with a full and comprehensive history. My newer black one i got 7 years ago shows 2bar in hot weather and this is totally normal.Again a pampered very low mileage car. I'm sure if any of us buy a new sender unit it will show improved oil pressure at the gauge for most people.

About your water temp sitting at 3/4 of the gauge,that doesn't sound right and way too hot.Are you fans kicking in via the rad thermo switch? Suggests you need to flush out your system to get rid of the crap in there.If that doesn't work maybe time for a new rad. It should sit at 90 degrees,anything much above suggests either your thrashing it,and the thermo switch or fan isn't working, or the system is in need of an overhaul.

HTH.

leggy · 21-07-16, 11:33 AM

Quote:

Originally Posted by Crossle

...seal was gone on dipstick so replaced that...

Have you checked any other seals and components for the oil system Crossle?...
my reason for asking: I've had oil leaks from the head gasket, the cam shaft seal, and also from the oil/water coolant housing seal and switch on my boy (the housing seal being quite a common complaint on the B4 80 according to my mechanic!), and whilst I never experienced any of the oil warning lights/buzzers that you yourself have described whilst I had those leaks, I would assume that it's quite plausible to expect a loss in oil pressure with any leak, big or small, and well, I've certainly noticed a huge difference in my boys engine, gauges and oil (more the level) performance since having all of my aforementioned leaks fixed.

leggy · 21-07-16, 11:51 AM

In view of your brake issue, ABS issue, and oil pressure issue Crossle...
not to mention the lack of funds that you raised on another thread, well would it not be best for you to just take 1781cc up on his offer to run a diagnostic so that you can see what faults (if any) do show up on a report? - gotta be better to address/replace actual faults/parts than to sit here guessing, and in turn, getting yourself stressed out over it all to the point of not sleeping, and I'm only saying this cuz I know how impatient you are with your cars and want to try and help you get her fixed as quickly and as cheaply as possible buddy.

mikes2 · 21-07-16, 12:31 PM

Sounds like possibly a problem with the low pressure switch as it's not supposed to trigger the warning until it's down at 0.3 bar.

Sensor in question is the large sensor on the block next to the radiator and it also drives the gauge in the car

You may have to consider getting a proper oil pressure test done if the sensor checks ok

vorsprung durch technik · 21-07-16, 12:33 PM

Quote:

Originally Posted by mikes2

Sounds like possibly a problem with the low pressure switch as it's not supposed to trigger the warning until it's down at 0.3 bar.

Sensor in question is the large sensor on the block next to the radiator and it also drives the gauge in the car

You may have to consider getting a proper oil pressure test done if the sensor checks ok

Wasn't that what i said?

John. · 21-07-16, 12:38 PM

Think I'd be for concentrating on getting the coolant temperature in check and see if that sorts the low pressure on the oil gauge.

mikes2 · 21-07-16, 12:39 PM

Haven't seen anyone giving such an answer

21-07-16, 09:33 AM	#11
vorsprung durch technik 4 ring whore! Classic Audi Club Member Join Date: Feb 2014 Location: Near Watford. Posts: 7,758	An oil change for decent quality oil could well make a difference,quality oil is so important imo. On this very subject i've read that sender units play up over time like any electrical items can and do and this could well be your reason for 1bar showing and the alarm going of. Once the oil has been replaced i would replace the oil pressure sender before any other investigations as it's been covered before and replacing the sender did the trick. HTH. Last edited by vorsprung durch technik; 21-07-16 at 12:41 PM.

21-07-16, 12:31 PM	#17
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	Sounds like possibly a problem with the low pressure switch as it's not supposed to trigger the warning until it's down at 0.3 bar. Sensor in question is the large sensor on the block next to the radiator and it also drives the gauge in the car You may have to consider getting a proper oil pressure test done if the sensor checks ok __________________ 1991 90 quattro 20v sport 1991 90 quattro

21-07-16, 12:39 PM	#20
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	Haven't seen anyone giving such an answer __________________ 1991 90 quattro 20v sport 1991 90 quattro

21-07-16, 11:51 AM	#16
leggy Senior Member Join Date: Nov 2014 Posts: 1,650	In view of your brake issue, ABS issue, and oil pressure issue Crossle... not to mention the lack of funds that you raised on another thread, well would it not be best for you to just take 1781cc up on his offer to run a diagnostic so that you can see what faults (if any) do show up on a report? - gotta be better to address/replace actual faults/parts than to sit here guessing, and in turn, getting yourself stressed out over it all to the point of not sleeping, and I'm only saying this cuz I know how impatient you are with your cars and want to try and help you get her fixed as quickly and as cheaply as possible buddy.

21-07-16, 12:38 PM	#19
John. 4 ring whore! Classic Audi Club Member Join Date: Mar 2011 Location: Scottish Borders. Posts: 7,526	Think I'd be for concentrating on getting the coolant temperature in check and see if that sorts the low pressure on the oil gauge.