Oil pressure flashing lights and buzzers!!

mlmcelligott

Guest
Hi guys, I'm new to the forum so hello everyone :)

I drive a 2004 1.9TDI Toledo. Yesterday after a long motorway journey and just after i got off the ramp and slowed down the oil pressure warning light started to flash red and a buzzer sounded a few times. Terrified I had killed my car, I pulled over and then all went back to normal, engine sounded fine and nothing seamed to be wrong.

Then after driving I noticed the alarms would sound if I was in the 1500 - 2000 rev band and would stay sounding until I either braked or accelerated out of it.

After a bit of research it could be either both, or one, of the two high and low pressure switches. I serviced the car today and noticed the high pressure level switch just below the oil filter housing but dont know where the low pressure level switch is.

Im guessing it must be a switch problem as I drove another two hours again today and had no problems until I reached the end of my journey when I had to slow down. Engine temp is fine and I havent noticed any dull in power.

Just for completeness I did top up the oil about two weeks ago and when I drained it today the level was a small bit on the high side. Im not sure did that have anything to do with the fault.

What are the part numbers of the two switches and is the any website where I can buy them for delivery to Ireland.

Cheers
 

S3 AKR

livin' the dream!!!
Jun 30, 2004
1,453
1
Colchester, Essex
As always, these part numbers are from quite an old version of ETKA (Revision 7, Update 243) so check them via a dealer.

038 919 081 K - only oil pressure switch listed (other than one for power steering)
N 016 024 1 - seal (number 6 in the pic)


oilpswitch.jpg


switches-ARL.jpg
 

mlmcelligott

Guest
Thanks for the reply. Just ordered that switch now. Kinda surprised to hear there was only one switch so I had a good look around the engine and I cant find a second one.
 

mlmcelligott

Guest
Just to add ive now noticed that just after i start the car i get a few yellow oil warning lights. Is this a faulty oil level sensor?

So far Ive bougth the pressure sensor on the oil filter housing. Its rated for 0.7bar.
Ive also bought a new replacement oil level sensor that fits into the underside of the sump.

After reading around here I'm getting scared now that the oil pickup is partially blocked. I checked the pressure against another toledo tdi and they are both the same.
 

Muttley

Catch that diesel!
Mar 17, 2006
4,987
31
North Kent
From the manual, the various indications that the oil warning light can give are:

11 - Engine oil pressure/level
The warning lamp lights up for a few seconds as a functional check when ignition is switched on.

If the warning lamp is red or yellow or flashes it indicates that the engine oil pressure or level is too low. This warning lamp will also light up if there is a defect in the oil level indicator.

*If lights up or flashes red (insufficient oil pressure)*
If the warning lamp lights up or flashes red while driving an acoustic signal will sound three times at engine speeds above 1500 rpm. Stop and switch engine off: check oil level and add oil, if necessary. See page 3.41
.
If the warning lamp flashes even though the oil level is in order, do not continue driving. Do not even run the engine at idling speed. Call in expert assistance.

If while driving the engine speed decreases below idling speed the oil pressure warning lamp may light up. Increase engine speed by accelerating or changing down gear.

*Lights up yellow (oil level too low)*
The yellow warning lamp indicates that the oil level is too low. Stop engine and add oil- see page 3.41.
When opening the bonnet the oil level warning is reset. However, if you do not refill oil the warning will reappear after about 100 km.

*Flashes yellow (defective oil level indicator)*
If the oil level indicator is defective an acoustic signal will sound and the warning lamp will flash several times.
From the moment of the defect to the check-up of the engine the oil level needs to be checked regularly, preferably when filling the tank.

Flashing red with buzzer indicates low pressure. Oil pump worn, pickup mesh blocked or oil filter blocked. When did you last change the oil filter, and did the problems start right after the change?

Flashing yellow and buzzer, on the other hand, means the level/temperature sensor in the bottom of the sump has failed. Much less of a problem.

0.7 bar is the correct switch. I don't think any of the TDI's, and not many of the petrol engines, have a second, low pressure switch (usually located on the cylinder head).

Are you sure you have an oil level/temperature sensor in the sump? Not all cars do. Having said that, I discovered mine had one when I was underneath it fixing a water leak.
 

mlmcelligott

Guest
Im thinking it might be the oil pickup thats partially blocked.
I just called into a machanic earlier and I'm gonna drop it in to him in the morning to get the engine flushed. Pity to ruin oil thats only 3 days old but I'm hoping this might solve the problem of partially blocked oil pickup. He said hes just gonna use an engine flush additive a leave it on high idle for a while to clean it out before draining it.
Would that be enough to unblock the oil pick up strainer if it was blocked?

The flashing red oil light and buzzer started nearly two weeks ago. The engine isnt getting any hotter and I can see oil making its way up to the head. I'm still driving it about 10km a day to and from work in light traffic.

My toledo has an oil level sensor on the sump.
 

Dox1966

Active Member
Jul 13, 2007
243
1
Golf mk4s have a switch on the bonnet catch, if the bonnet isn't shut properly it puts the oil light on the dash - the idea is you open the bonnet and check the oil (which is ok) and you shut the bonnet.

HTH
 

Muttley

Catch that diesel!
Mar 17, 2006
4,987
31
North Kent
Flashing red and buzzer means low oil pressure, and you shouldn't drive it, you'll certainly be getting more wear on the bearings and moving parts, especially the turbo which needs copious oil for lubrication and cooling.

You are unlikely to clear a blocked pickup by flushing the engine. You need to drop the sump, take off the pickup and clean the strainer mesh properly.

When replacing the sump, make sure the sealer that is used instead of a gasket is applied close to the outside edge of the join (but looping just inside each bolt hole) and is not too thick. You don't want any to squeeze out into the sump itself, because it hardens and crumbles, and the crumbs block the pickup strainer again . . .
 

mlmcelligott

Guest
update

Got the car back from the mechanic today. He flushed the engine and said the oil pressure is fine. He also changed the oil pressure switch.

Still got a flashing red oil pressure light and buzzer a few times on the way home.
He did say the flashing yellow oil light at start up was the low oil level sensor in the sump and Ill change that next when it arrives.

Could the low oil level sensor produce the flashing red oil light a buzzer?
How do i test the bonnet switch?
 

mlmcelligott

Guest
Had another look and found a frayed wire on the wiring loom. I cut it and joined it using a connector and its seams to have solved the problem. The yellow flashing light at start up doesnt come on anymore. Havent taken it for a spin yet but hopefully thats the end of it
 

Muttley

Catch that diesel!
Mar 17, 2006
4,987
31
North Kent
Your mechanic needs to explain in great detail why, if he says the oil pressure is fine and he has changed the pressure switch, you are still seeing a low oil pressure warning (flashing red oil light and a buzzer).

Can I check that we're talking about the right indication here: your dash display should look like this:

Dash.png


The oil light is in the rectangular set of annunciators and is flagged 21 in the diagram.

If the light flashing red at you is number 3, then it's the water level/temperature sensor. Often caused by deposits on the level sensor prongs in the header tank.

Please excuse me if I'm teaching my granny how to suck eggs, but I've seen the indications mixed up before now.
 

mlmcelligott

Guest
The oil light is in the rectangular set of annunciators and is flagged 21 in the diagram.

If the light flashing red at you is number 3, then it's the water level/temperature sensor. Often caused by deposits on the level sensor prongs in the header tank.

yip it was the number 21 that was flashing. Found a broken wire and all is good now i think. I havent taken it for a run yet but the initial flashing yellow oil light at start up isnt there any more so hopefully its solved now
 

mlmcelligott

Guest
problem came back after 3 weeks of hassle free driving. I put up nearly 1500 miles since the last time the light came on and now it came back on today. I got the low oil level sensor so ill drop the sump and replace it tomorrow. Will clean the oil pick up too.

Last time i took it to the garage the mechanics couldn't find anything wrong but did mention that the crankshaft seal had a small leak. Im guessing that seal is expensive to change since you need to get the timing belt changed to get at it? Could the leak in the seal contribute to low oil pressure? In the two years that ive had it ive had to top up the oil only once so its not a big leak at all.
 

sagemwill

Guest
Unlikely to be the seal that's the problem. The two things that it could be are 1) The sensor (by far the cheapest) 2) The Oil Pump - anything from £100 depending if you can get hold of a refurb.

Had a similar problem with my Cupra and it turned out to be the oil pump. Make sure you change th 'O' rings as well if it is the pump.
 

Muttley

Catch that diesel!
Mar 17, 2006
4,987
31
North Kent
If you mean that your oil light is flashing red, I refer you to post 5 in this thread.

*If lights up or flashes red (insufficient oil pressure)*
If the warning lamp lights up or flashes red while driving an acoustic signal will sound three times at engine speeds above 1500 rpm. Stop and switch engine off: check oil level and add oil, if necessary. See page 3.41

You have a low oil pressure indication. Do not drive until you've fixed it.
 

drozia

Active Member
Mar 27, 2013
9
0
Hello. I have a seat Cordoba 99' SX TDI AFN engine. When I climbed mountain I felt a power loss then a few minutes later on idle speed oil pressure warning lamp winked. I stopped engine. Started again and problem was still continued. I stopped. 30 minutes later I checked oil level and any leakage but there was no problem. Level was fine. I started engine again then warning lamp did not flashed. I steped on the gas to 5000 rpm engine responded well without flashing. Now what is the problem? should I change oil and filter? or pressure switches? Hereof my oil pressure gauge reads over 5 bar always...
 
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