urgent help needed oil light coming on

Post by **Wear Sunscreen** » 02 Sep 2017, 13:52

Hi
My oil light has started to come on when on tick over or a bit faster. No undue engine noises or problems, temperature normal, oil level appears ok. This happened a few days ago and I had a new oil switch put on, everything appeared normal after that, but now it has started coming on again.
I am due to go away Sunday will travel about 150 miles. Would be really grateful for some advice.

Post by **kevtherev** » 03 Sep 2017, 20:25

What grade oil are you using?
And when was it changed?

Post by **Wear Sunscreen** » 04 Sep 2017, 07:18

Using 15/40 oil. Must admit I think it is over 12 months since last oil change!

Post by **kevtherev** » 04 Sep 2017, 07:40

Wear Sunscreen wrote:Using 15/40 oil. Must admit I think it is over 12 months since last oil change!

Well there's one thing you can eliminate.

Every 3500 miles or 6 months
Whichever is soonest

Post by **lefty67** » 04 Sep 2017, 07:51

What engine is it?

Post by **Mr Bean** » 04 Sep 2017, 08:48

I am not offering this as advice but:
To be honest after a couple of unexplained oil light flicker issues since a rebuild some ten years ago I now use 20/50 in my well thrashed 2.1 WBX although the subject of oil is about as contentious as Politics or Religion in certain circles :roll.

CS

Post by **DoubleOSeven** » 04 Sep 2017, 09:09

Thicker oil may keep you rolling for a few more months, but we need you to pull the spark plugs and do a compression test (king lead off). Then we know the state of your engine. In my book, oil light flickering at idle = worn bearings. Sorry, don't shoot the messenger.

Test kit on ebay for £11

Post by **Wear Sunscreen** » 04 Sep 2017, 10:06

My engine is a 1.9 water cooled.
The light doesn't come on until the engine has warmed up and then only comes on when at lowish revs, doing about 40 mph in 4th gear. I goes out above that.

Post by **CJH** » 04 Sep 2017, 10:33

Wear Sunscreen wrote:My engine is a 1.9 water cooled.
The light doesn't come on until the engine has warmed up and then only comes on when at lowish revs, doing about 40 mph in 4th gear. I goes out above that.

If it's a four-speed, then 40mph in 4th is about 2000rpm. Your oil pressure should be 2 bar minimum when the oil is at 80º (which is warm, but not the hottest it will get). If your engine is hotter than that, then that 2 bar minimum is a bit lower. Assuming you've got the correct pressure switch driving your warning lamp (should be 0.25 or 0.3 bar - the blue one), then this means your oil pressure is dropping below 0.3 bar at 2000 rpm. That's seriously low.

To give you an idea, later vans (did you tell us the age of your van?) have an extra pressure switch (0.9 bar, the grey one) which drives a warning buzzer. But the buzzer only sounds if the pressure drops below 0.9 bar AND the engine speed is above 2000 RPM (I think). So to be clear, VW felt that you need to have a warning buzzer to alert you of a problem if your pressure drops below 0.9 bar when the engine speed is above 2000 RPM. Yours is dropping below 0.3 bar at that engine speed.

Could be that your oil pump isn't working well (excessive end float?), but it could also be that your engine is worn out.

Post by **Wear Sunscreen** » 04 Sep 2017, 10:43

Many thanks for your answers.
The vehicle is a 1984 model so pre the buzzer. The switch that is on is a white one, which I assumed to be the original and has been on for at least 10 years without any problems.

Post by **CJH** » 04 Sep 2017, 10:50

The pressure switch between your pushrods is white? This one? So your light might be coming on at 1.8 bar - that's a lot more respectable. I'd suggest you get the proper switch and see what happens to your light. It's a fiddly thing to swap, especially if your pushrod protection plates are still attached to your exhaust studs. If you take the old one out and it's not too corroded you may be able to read what pressure it's set to - it may be engraved on it.

Post by **Wear Sunscreen** » 04 Sep 2017, 11:03

Thanks for that CJH, I will attempt to put a blue one on.

Post by **marlinowner** » 04 Sep 2017, 12:33

The 1.8 bar (or 0.9 bar) switch is a normally open one whereas the 0.3 bar switch is a normally closed. If a 1.8 bar switch is fitted in place of the 0.3 bar one then the oil pressure light will be off when ignition is on but engine not running, and then come on when oil pressure goes ABOVE 1.8bar.

Post by **CJH** » 04 Sep 2017, 12:37

marlinowner wrote:The 1.8 bar (or 0.9 bar) switch is a normally open one whereas the 0.3 bar switch is a normally closed. If a 1.8 bar switch is fitted in place of the 0.3 bar one then the oil pressure light will be off when ignition is on but engine not running, and then come on when oil pressure goes ABOVE 1.8bar.

Haha, ok then, it's probably not one of those then! Is the colour convention universal? Is it possible that the switch that's fitted operates at the right pressure but is the wrong colour? Or maybe it's a grey one (0.9 bar) that looks white?

Post by **Wear Sunscreen** » 04 Sep 2017, 14:59

I'm a bit confused now!
So if a white switch (1.8 bar) is installed instead of a blue one (.3 bar) (as mine is I assume) then when ignition is on but engine not running, the light should be off.
Is this correct?

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