Oil Light problem...

[SammySJ99]

OK so t days ago I noticed that my oil light was flashing at me... Here is a little history on my car...

I bought it like 6 weeks ago from the original owners who I thught were taking really great care of it... I mean the car isnt a total pile... I got it home and the drive shaft connector broke so the car would not go into reversr, 1st or 2nd... Ok so we ordered that part and poped the ld onf back on and are waiting for it to pop off again to replace it with the new one... on problem down... out of 100's i am finding...

about 2 weeks ago I changed the oil and the filter... The filter is a good one I know that but I forget what brad... Starts with a B... put in the oil the book (haynes) said to put in... changed the plugs and the wires and the air filter and we flushed the cooling system the best we could with a hose and water... I know I need to get a really good flush done at the end of summer because these people never used coolant... WHatever we put in comes out a rusted color...

I was driving home the other day and when I pulled into the driveway (it is at a slant) the oil light flashed for a sec... I turned the car off and didn't think much of it... Yesterday driving home from work the oil light came on again. it would stop flashing if i tapped the gas, was moving, or the car was not warmed up all the way... It only does it when the car is warmed up all the way... VWVortex people say to change the oil to a thicker oil... Has anyone else had this problem?

[CalAltaDubber]

Six is probably the best advice about the oil problem, but what does the oil pressure gauge read when the light is flashing? The gauge should ( I believe) read not less than 2 Bar with the engine at 1000 RPM.

Make sure that you give the cooling system a good flush. It is normal to see rusty coloured fluid come out, especially if it has not been flushed for several years. If you can flush the system with a pressure, so much the better. Also it is probably a good time to replace the thermostat, so flush the system with the thermostat removed and the housing installed. then install the thermostat.

Finally don't skimp on the anti freeze. Sure you live in California, but the anti freeze is also the lubricant for the water pump as well it helps disapate heat in hot weather.

Hope this helps

[SammySJ99]

I planed on just taking it to a shop and having it flushed next time I change the oil... I mean in 3K miles... It is working 100% better already...

[sixsracing]

First off, I have to ask a really dumb question. Are you sure it was the oil light that came on? Was there a buzzing noise also? The reason I ask is that many people confuse the low coolant light and the oil light.

Now that we have that out of the way. Oil pressure senders are common replacement items in these cars. They are color coded and cheap enough that you should just go to the dealer and get a direct replacement. Cal is right about the pressure, should be between 1 bar and 2 at idle and hot. Start up cold it should peg the gauge. I would probabyl be running 20w50 Castrol GTX (I am biased towards Castrol)in your region in the summer, 10w 40 in the winter. The cars are also sensitive to filter quality. Mann, Mahle, VW or some quality European filter is best.

Check all the connections on the oil switches. One at the filter housing, the other at the transmission end of the block. The big one with two wires coming off of it is for the gauge and you don't need to worry about it right now. Check the wires for abrasions, they could ground out momentarily and give this symptom. Common grounds are under the dash on the drivers side behind and above the kick panel. Remove these and clean them well, it will pay off later.

Running straight water in these cars will cause the coolant light to flash intermittently. The sensor in the tank can sense ionization and will cause the light to flash if it feels the concentration of coolant is weak.

If you are using Valvoline, Penzoil or another cheap brand of oil, try swapping it out with Castrol and see if it helps.

These cars have a lot of little quirks. With patience you can work 90% of them out, the remaining 10% will remind you of your relationship with a significant other. Yes, it's annoying.....but you love them.

[SammySJ99]

There is no buzz when this light comes on... Just a flashig red light... I don't think I have a low coolant light unless it is by the needle for the temp reader... This thing is clearly marked oil... I didn't look at the gauges... I don't even know if these things are working right... I don't trust them at all...

[Calimus]

Ok, moron question here, have you checked the oil level on a nice flat level surface? These cars are a bit old and some burn/use/leak oil. If it's at proper level, then first try checning it to 20w50 and use a proper filter (as already mentioned) .

Another thing is that it could just be a malfunction. Sometimes the circuit board that controls the low-oil pressure warning light (and generally the accompaning buzzer) has been known to crack and give false readings.

Try the things that have been mentioned thus far and let us know what you find, from there, we can give you loads of other things to check which only costs time and much less $$ then dropping it off at the shop.

[kamzcab86]

Nothing more to add, except: '89s don't have coolant level sensors, only temp sensors

Minimum oil pressure: 2 bar at 2000rpm at 80*C

[CalAltaDubber]

Nothing more to add, except: '89s don't have coolant level sensors, only temp sensors

Minimum oil pressure: 2 bar at 2000rpm at 80*C

I stand corrected, I was quoting from memory. Thank you Kami.

[sixsracing]

89's don't have level sensors? I thought they had been around longer than that. Golf's had them in 87', Vanagon's in 84'. I assumed (wrongly) that Cabriolet's did too. My bad.

[SammySJ99]

Well When I chenged the Oil I put in a BOSH (i think thats the name) filter... I was told these are good ones to use too... THe car does not leak oil, I don't think it is burning it... Tthe car really purrrrssss like a car should...

I did co buy 20w/50 oil last night because I think it might just be the oil... I want to try this before I go replacing things... Only because like I said... I plan to replace the engine I hope with in the next year, so I don't want to replace things twice... If the ligt still flashes after this I will then try the sensor and go from there....

[cwingerter]

My cabby has a similar issue...The light will only flash (no buzzer)under the following critieria:
1. Engine - good and hot - like after hwy
2. RPM drops below 1000 RPM


But not always...
Can anyone confirm that the low pressure sensor is prone to failiure?

[chloeroxymax]

This Saturday, I took my 1990 Cabby on the first trip of any distance, around 100 miles total round trip.

After 20 or so highway miles, as I would come to a stop, I'd get the oil light. The oil pressure gauge got as low as 1.8 bar or so, at a temp of 90+C. At what pressure is there a real danger? I'm not sure the light is telling me anything meaningful... the gauge can give me an indication of a real problem, and I'm pretty confident that it's working.

I'm using Castrol 10W40, but I think I'll change to 20W50 when I change the oil this weekend, and see if it makes a difference.

Does anyone live in the same climate as KY and use 20W50 in the winter? I'm not going to drive the thing when it's 10 degrees F out, but would it be OK at 25? I know that 20W50 would be fine in the summer...

Other than the blinking coolant light and this occassional oil light, I'm loving working on this little car. Everything has been pretty easy and cheap to fix, and this forum has been great help.

[kamzcab86]

The gauges in these cars are not the most accurate instruments; the bar gauge gives you an approximate oil pressure reading, not exact. If you want to know the exact oil pressure, connect a mechanical oil pressure gauge. There should be 2 bar, minimum, at 2000 RPM. There are two oil pressure sensors/senders in the engine bay: 1.8 bar on the oil filter flange and a 0.3 bar on the head. Either one or both of these sensors could be going bad. For further information: http://reflectionsandshadows.com/cabby/dopws.html .

[gull]

After 20 or so highway miles, as I would come to a stop, I'd get the oil light. The oil pressure gauge got as low as 1.8 bar or so, at a temp of 90+C.

1.8 bar at idle, with an oil temp of 90 C? That's quite good, actually. My guess is you have a problem with one of your oil pressure senders.

[Briano1234]

Use a napa gold or wix filter... and 20w50 in the winter in KY won't be a problem. I used it in my MG in the 70's in Illinois, and I use 20W50 in Atlanta all the time....................