Oil light on but dipstick shows full oil M54B30

S

SteatoLegato

Member
Recently had oil light come on dash when switched off the car at the end of a short (30 min) drive. Waited for a few hours and checked oil level and its full - oil changed less than 3000 kms prior and no major leaks, no smoke. What could that mean?
Also recently had radiator and expansion tank replaced by a reputable mechanic - when I went to check coolant level after the car has been sitting for a few days, the system was under pressure and some coolant spat out , level still OK tho. Does that mean the bleeding was done wrong - should I be worried?
Thanks!!
 
MikeyH said:
I have the same thing, I think it’s a faulty indicator under the sump.
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If so, you should have a code for 'Thermal Oil Level Sensor'.
Another thing to check is that the o-ring seal is properly fitted on the bottom of the oil filter cage. If not, then as soon as you turn the engine off, the oil runs back to the sump and makes it look full. You are supposed to run the engine first, then check the oil as then oil will still be in the filter and give you a true reading.
If the o-ring is letting the oil straight back to the sump on shutdown then you'll get a false high reading.
 
Hours isn’t accurate. Afaik the book says something like check after 10mins and a minimum of 5mile journey.

If your dipstick is showing okay I wouldn’t worry. I trust that more than any old sensor.
 
As said, it'll be the oil level sensor. They fail, but are easy and cheap to change next time the car has an oil service (as it's located in the base of the sump).

As long as the red oil pressure light isn't coming on, and the dipstick looks ok, then it's not an urgent fix.
 
enuff_zed said:
If so, you should have a code for 'Thermal Oil Level Sensor'.
Another thing to check is that the o-ring seal is properly fitted on the bottom of the oil filter cage. If not, then as soon as you turn the engine off, the oil runs back to the sump and makes it look full. You are supposed to run the engine first, then check the oil as then oil will still be in the filter and give you a true reading.
If the o-ring is letting the oil straight back to the sump on shutdown then you'll get a false high reading.
Click to expand...
I hadn't realised that, I usually check it before I drive the car which would be pointless :headbang: Thank you (y)
 
MikeyH said:
I hadn't realised that, I usually check it before I drive the car which would be pointless :headbang: Thank you (y)
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Went out for a run to Hay Tor on Dartmoor, and checked it when I came back, needed some putting in. (y) Cheers enuff_zed.
 
I’ve had the thermal oil level sensor code for the past five years, never get the oil light on though.
 
Been over a week now since I did as enuff_zed said to do and still no beeping and light. So hopefully that's the answer. Thank you enuff_zed. :thumbsup:
 
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