Oil sensor(?) change help needed

Sylvester

Active Member
Weeks ago during a long few hours drive, the red oil lamp warning light appeared twice on the dashboard on my 1.4 petrol. They lasted a minute or so, then disappeared. I thought, well hoped, happened due long drive as I usually drive short distances, but last few days the red warning light came up again a few times, once 15 times in a row lasting few seconds each. That's not great.

I've done some research and either oil level too low or oil sensor is failing. I've been using the 2nd oil tube, front one was a failure even the new end broke off and got stuck before, but as my A2 has the rear oil tube option, if that's what called, so I bought the forum recommended parts and been using it, works great too. Oil level just over middle, so that's not the issue. Must be the sensor then.
I found lot of infos and apparently there's 2 oil sensors. 1, next to EGR and 2, on the bottom of oil crankcase next to the oil drain plug.
I've changed oil couple of months ago, I didn't have filter-remover tool so I didn't change that, and to replace the 2, sensor the oil has to come out again, so I want to leave that last. Also there's a slow coolant leak since I bought the car, almost 1.5 year ago. Loosing 1 glass amount a month, which drops down from the bottom oil sensor, so it's a bit cover in pink on the outside. Not sure that could cause this or not.
So let's change the 1, sensor by the EGR. (Pic attached)
Is there a "how-to" or someone can give some info about it, also which one is the right one for 1.4 petrol as there's a lot different ones on EBay.
Cheers guys.
Screenshot_2020-07-09-19-45-15.png
 
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Darpod14

Member
Weeks ago during a long few hours drive, the red oil lamp warning light appeared twice on the dashboard on my 1.4 petrol. They lasted a minute or so, then disappeared. I thought, well hoped, happened due long drive as I usually drive short distances, but last few days the red warning light came up again a few times, once 15 times in a row lasting few seconds each. That's not great.

I've done some research and either oil level too low or oil sensor is failing. I've been using the 2nd oil tube, front one was a failure even the new end broke off and got stuck before, but as my A2 has the rear oil tube option, if that's what called, so I bought the forum recommended parts and been using it, works great too. Oil level just over middle, so that's not the issue. Must be the sensor then.
I found lot of infos and apparently there's 2 oil sensors. 1, next to EGR and 2, on the bottom of oil crankcase next to the oil drain plug.
I've changed oil couple of months ago, I didn't have filter-remover tool so I didn't change that, and to replace the 2, sensor the oil has to come out again, so I want to leave that last. Also there's a slow coolant leak since I bought the car, almost 1.5 year ago. Loosing 1 glass amount a month, which drops down from the bottom oil sensor, so it's a bit cover in pink on the outside. Not sure that could cause this or not.
So let's change the 1, sensor by the EGR. (Pic attached)
Is there a "how-to" or someone can give some info about it, also which one is the right one for 1.4 petrol as there's a lot different ones on EBay.
Cheers guys.
View attachment 66889
Mine does the same, but only comes on the odd time, so I’ve bought the one at the bottom of the sump, only just serviced the car but I’m just going to drop the oil and put new oil in. It’s £50 or so for the oil and sensor so worth it
 

Sylvester

Active Member
Mine does the same, but only comes on the odd time, so I’ve bought the one at the bottom of the sump, only just serviced the car but I’m just going to drop the oil and put new oil in. It’s £50 or so for the oil and sensor so worth it
Is there a how-to? Also what the top sensor of the bottom one is oil sensor as well? Cheers
 

Darpod14

Member
Is there a how-to? Also what the top sensor of the bottom one is oil sensor as well? Cheers
the bottom one is an oil level sensor, not sure about the top one, if your oil level light is coming on and your oil is fine then it could be that.
better to wait for others who are more knowledgeable to answer though.
 

Sylvester

Active Member
the bottom one is an oil level sensor, not sure about the top one, if your oil level light is coming on and your oil is fine then it could be that.
better to wait for others who are more knowledgeable to answer though.
Okay thanks.
 

BobbySox

Member
I think the lower sensor (sump) is for oil level and higher sensor for oil pressure.
A broken dip-stick end can also cause oil light 'flicker' when trapped in oil pick-up pipe!
 

Sylvester

Active Member
I think the lower sensor (sump) is for oil level and higher sensor for oil pressure.
A broken dip-stick end can also cause oil light 'flicker' when trapped in oil pick-up pipe!
That's sounds about right, not too sure what's the main difference though as both come on when oil level is low. Any giude how to change them? Cheers
 

bretti_kivi

Member
The sensor at the bottom is the one that usually fails. You will need to drain the oil. Apparently it is next to the climate compressor. But you could just log in to Erwin at erwin.audi.co.uk and get the full correct instructions for a few quid.

- Bret
 

bretti_kivi

Member
That's sounds about right, not too sure what's the main difference though as both come on when oil level is low. Any giude how to change them? Cheers
They do not. Level will be normally an orange light first, then red. Pressure tends to go red first, and they're actually two different symbols. If the level sensor has failed, you will see the word 'SENSOR' next to the red oil can. I would expect an error to be logged anyway... I would scan first. Pressure is the one at the top, level the one in the sump.

- Bret
 

Sylvester

Active Member
They do not. Level will be normally an orange light first, then red. Pressure tends to go red first, and they're actually two different symbols. If the level sensor has failed, you will see the word 'SENSOR' next to the red oil can. I would expect an error to be logged anyway... I would scan first. Pressure is the one at the top, level the one in the sump.

- Bret
Hi Brett, it's the red flashing and beeping for symbol. I've upgraded to use the 2nd dipstick option as my A2 still has that, the oil level almost full, yet it still beeps few times a week. When I stop the car the the issue completely gone. Cheers
 

Sylvester

Active Member
Hi guys, can recommend which "oil pressure sensor" to get? There's some on the link and a lot on eBay too with different brand/price, not sure which one to get. Cheers


Also on eBay 5w30 4L is on for £24.99, someone might be interested:
 

Welshboy

Member
I have a 1.4 aua petrol A2 and I changed mine recently. The one I bought was this Oil pressure switch/sensor and it works. Be carful when tightening it - no more than a quarter turn . A previous owner tightend the one on mine and cracked the block. If you put permatex 59214 in the first 2 male threads then cotton buds are useful to clean the threads of oil on the female part.
 

Sylvester

Active Member
I have a 1.4 aua petrol A2 and I changed mine recently. The one I bought was this Oil pressure switch/sensor and it works. Be carful when tightening it - no more than a quarter turn . A previous owner tightend the one on mine and cracked the block. If you put permatex 59214 in the first 2 male threads then cotton buds are useful to clean the threads of oil on the female part.
Had a feeling that sensor is sensitive so I was trying to be careful at checking, cheers.
 

Sylvester

Active Member
I've ordered the oil pressure sensor and new oil, just to make sure that's done too, even though it was done few months ago, but the oil got dirty very quickly again and cause "red flashing warning".

Anyway question is, if the real reason for "red flashing light" isn't the FAILED OIL PRESSURE SENSOR, but the inside engine compenents (e.g. failing bearings etc.) cause the LOW OIL PRESSURE, what are the symptoms of that? Apart from 20 seconds smoke at start up for long time, I don't experience any driving issue. Car starts, drives and pulls as before. Thanks
 

Welshboy

Member
I would get a garage to do an oil pressure test . If that is ok then it is either the sensor or the wiring- looking at your pic the wire looks twisted- the line in the wire rotates as far as I can tell
 

Sylvester

Active Member
I would get a garage to do an oil pressure test . If that is ok then it is either the sensor or the wiring- looking at your pic the wire looks twisted- the line in the wire rotates as far as I can tell
Yes I've noticed as well, I'd tried to twist it back, but then looks even more twisted and the cables go too deep so not sure how to check the other end.
Its been twisted since I bought the A2 last February and the "red flashing warning" only began coming on 3 months ago after long drive, and now usually after more than 20m drive, not short distances like driving to work. But then it beeps, keep disappearing like 1-2 min and beeps again. No engine light has come on with that and no fault codes at vag check. Hence I hope the wire is okay, but looks twisted to me too.
I haven't lost any power either, revs through all ranges no issues apart from occasional beeping, only issue the 20 second smoke when I start the car, but then nothing drive, temp sits on 90.
Can it still be engine part problems, like damaged bearrings or vales? I'm changing oil, filter and oil pressure sensor, which I hope is the real culprit, tomorrow. Cheers
 
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Sylvester

Active Member
So, to fix the on-off "red flashing oil can" warning, I planned to follow:
1st-change oil+filter and replace oil pressure sensor
2nd- if warning light still appears , oil pressure test at the garage.

On the day, the oil pressure sensor didn't arrive in time, so only oil+filter got changed. But to my surprise next day, after 1 hour drive no warning light came on at all! Hasn't happened for months. That's a good start as I gotta drive more soon.
Now I've received the oil pressure sensor, which looks identical to the old one, but the bottom hole, which gets filled with oil, is 2-3x bigger.
Is that good or bad thing? Shall I just not change the oil pressure sensor? Thanks
 
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