Oil level or pressure light?

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Bikergonebald
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Oil level or pressure light?

Post by Bikergonebald »

Hi, I have a 2004 1.2 petrol. When the engine oil light comes on is that because it sensing a low level or is it from a pressure switch and therefore the damage is already done?

Thanks
Johntheo1
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Re: Oil level or pressure light?

Post by Johntheo1 »

Obviously check the oil level if it comes on, not sure about this model but normally the oil pressure warning (if oil pressure is the problem) does not annunciate until the engine revs are > something like 1600 RPM or there abouts.
RUM4MO
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Re: Oil level or pressure light?

Post by RUM4MO »

Normally on VAG cars, the oil low pressure output is inhibited for a few seconds after the starter is engaged, and then enabled at all revs, proof of that can be found if you need to crank the engine for an extended period without it firing - a sounder will go off and a low pressure warning message will be handed out on the small display panel - I can't think of where it is given if the car has basic level display though.

The oil pressure and the oil level lights are different (I think from memory) and so different colours.

Check the sump of your car to see if there is a metal blob fixed onto it that has a cable attached to it, if so then your car has a low oil level warning system, if not then it hasn't.

These oil level warning units and/or their wiring can go faulty and give out a warning when the level is okay.
Bikergonebald
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Re: Oil level or pressure light?

Post by Bikergonebald »

Thanks for your input guys.
The light came on yesterday when my son was driving and he continued to drive for about 2 miles to get home. The oil level was very low, still on the stick but below the low level mark.

If the warning light was based on level I expect all will be ok. If it was based on pressure I expect the crank bearings will be in a bad state.
Johntheo1
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Re: Oil level or pressure light?

Post by Johntheo1 »

If the warning light doesn't come on once the revs are > say 1600/2000 RPM then it was the low level, the same warning light is utilized for both.
Bikergonebald
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Re: Oil level or pressure light?

Post by Bikergonebald »

He used the car again today, plenty of oil this time but the warning light still came on. I tried it and the warning only comes on if the revs go above 1500 so i'm assuming the most likely cause it a blocked pick up pipe. That are the bearings are wrecked but it doesn't make any strange noises and runs fine.

Worth changing the pump while i have the sump off?
Johntheo1
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Re: Oil level or pressure light?

Post by Johntheo1 »

Has a new oil pressure switch been tried?.

If the warning light doesn't illuminate with ignition only on then do the following......or do it anyway one way or the other.
If you can use a multimeter select resistance and with probes between P.switch terminal and earth, resistance should be zero (P.switch closed contacts). With engine running resistance should be infinite (P.switch open contacts)
Bikergonebald
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Re: Oil level or pressure light?

Post by Bikergonebald »

I haven’t tried the switch. I guess I should rather than assuming the worst and taking it apart. I can test it with a multi meter.

If it’s the same switch in the 1.4 engine I can swap it over from my wife’s car and try that.

Thanks for the suggestion it might save me a lot of hassle.
Bikergonebald
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Re: Oil level or pressure light?

Post by Bikergonebald »

It was the switch! A quick and cheap fix.

Thank you.
Johntheo1
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Re: Oil level or pressure light?

Post by Johntheo1 »

Delighted you have it sorted. :D
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