Low engine oil
Discussion
Took my Monaro out for a spin yesterday and engine went into limp mode with a warning to stop and check the engine. Checked the oil and it was well below minimum (checked less than 300 miles ago and was between min and max). So put just Less than a litre of RP in it, checked the level 3 miles up the road and it was well above max. So my questions are, why did the engine go into limp mode? Why was the oil level so low (definitely not leaking), and why only topping up with less than 1 litre is it now well above max?
Many thanks in advance.
Andy
Many thanks in advance.
Andy
This is an interesting one, The engine went into limp home mode to stop itself from seizing up, it sounds like an oil pressure switch issue?
When mine failed the gauge on the dash went to zero, but I had no other issues.
It might be worth taking the oil pressure switch out and connect up an accurate pressure gauge to check the reading. This sensor is located at the rear of the intake manifold.
I believe you can also do this test next to the oil filter housing where the two bolts are located and thread the gauge in there.
I’m puzzled by the oil level on the dipstick though, especially when you only had to add a small amount to bring the level back up?
If the oil is low, it’s either been burnt: leaked out or mixed with coolant, which doesn’t seem to be the case here!
I’m struggling now so here are a few random thoughts, make sure the oil is the correct grade:
maybe there is a blockage somewhere, a failed or blocked oil filter, or oil pump on the way out.
Also see if any fault code have been stored.
Sorry I can be more helpful but it might give you a few ideas.
I’d say there are two things going on here - the oil pressure switch failure is a common, albeit terrifying thing when it happens. I’ve lost two now and on both occasions the car was running fine, with normal oil level. Second, always keep the oil level on the “max”, they don’t like being run low so by the time it’s towards the bottom of the stick, it’s too late. Also, it takes a while for the oil to drain back into the sump so always leave it for 10 minutes before checking the level. Assuming it’s now not making any funny noises, you should be fine. A little bit over on the stick should be OK but if you are worried, drain some out.
The dipstick reads the same (just over max) whether you have 5L in it or the recommended 7L , because of the shape of the sump.
If its below the low level on the dipstick you have nowhere near enough oil, its probably sloshed around enough that you drew in air to the pump and low pressure put you in limp mode.
If its below the low level on the dipstick you have nowhere near enough oil, its probably sloshed around enough that you drew in air to the pump and low pressure put you in limp mode.
stu vxr said:
So just to be clear all, are we saying the dipstick on our cars is totally unreliable?
News to me after 12 years of ownership? Should I be worried weird?
Fred is just saying that because of the shape of the sump (probably about a 5 litre box and then a flat pan area next to it) the dipstick doesn't read much different, which'll be because the extra oil goes to fill up the flat area instead of further up where the dipstick is...News to me after 12 years of ownership? Should I be worried weird?
Picture for some visual representation, you can see where the dipstick goes in etc.
fred bloggs said:
The dipstick reads the same (just over max) whether you have 5L in it or the recommended 7L , because of the shape of the sump.
If its below the low level on the dipstick you have nowhere near enough oil, its probably sloshed around enough that you drew in air to the pump and low pressure put you in limp mode.
I like this theory, in light of the information we have it sounds totally plausible. If its below the low level on the dipstick you have nowhere near enough oil, its probably sloshed around enough that you drew in air to the pump and low pressure put you in limp mode.
It’s not something I was aware of TBH, so the moral of the story is keep an eye on the oil level.
I usually put in 6 bottle of Royal Purple in my 5.7….is that enough? I think they are each sold as an American quart if I remember correctly.
Hopefully Andy got his car sorted and it’s running well.
Yep, Improved Racing sell a nice bolt in (and actually bolts in...) baffle, although obviously has become a lot more expensive now the GBP is worthless 
In the states I believe GM recommend putting in an extra litre of oil if you're going to be tracking the car (or any sustained high cornering G)
If you imagine, the pickup is in the middle of the low section of the sump. Under sustained acceleration or cornering, whatever oil is left in the pan is going to slosh about a lot, and mostly away from the pickup.
Obviously this isn't some catastrophic concern, GM will have given the design plenty of testing etc. and there is a basic baffle in the sump anyway, but it's worth considering your usage and such. You're less likely to have issues slightly over filling than under filling, so I wouldn't worry too much about putting 6 litres in, or even 7.
I actually have a sump on the shelf at home, perhaps I'll take some pictures of what the various litres of oil look like in there...
In the states I believe GM recommend putting in an extra litre of oil if you're going to be tracking the car (or any sustained high cornering G)
If you imagine, the pickup is in the middle of the low section of the sump. Under sustained acceleration or cornering, whatever oil is left in the pan is going to slosh about a lot, and mostly away from the pickup.
Obviously this isn't some catastrophic concern, GM will have given the design plenty of testing etc. and there is a basic baffle in the sump anyway, but it's worth considering your usage and such. You're less likely to have issues slightly over filling than under filling, so I wouldn't worry too much about putting 6 litres in, or even 7.
I actually have a sump on the shelf at home, perhaps I'll take some pictures of what the various litres of oil look like in there...
stu vxr said:
This is very interesting, I had no idea about the sump issue, a picture of the sump design inside would be very helpful.
These are just snipped from my enormous build thread, but another angle of the outside:Edited by stu vxr on Monday 26th September 19:37
Empty sump, that's the Improved Racing baffle on the left, the stock one visually doesn't look too different.
Sump with baffle in, can see the hole where the pickup tube goes through in the middle, and also can see the dipstick hole.
Can see what the pickup tube looks like here:
Just to add and clarify for OP.
Low oil pressure will specifically give a low oil oressure warning and a symbol of an oil can.
You say it went into limp mode.
The two are entirely unconnected. You have assumed the low oil level was the cause. It wasnt. Something else was. This will be stored in the memory and can be read with an appropiate scanner.
Low oil pressure will specifically give a low oil oressure warning and a symbol of an oil can.
You say it went into limp mode.
The two are entirely unconnected. You have assumed the low oil level was the cause. It wasnt. Something else was. This will be stored in the memory and can be read with an appropiate scanner.
monkfish1 said:
Just to add and clarify for OP.
Low oil pressure will specifically give a low oil oressure warning and a symbol of an oil can.
You say it went into limp mode.
The two are entirely unconnected. You have assumed the low oil level was the cause. It wasnt. Something else was. This will be stored in the memory and can be read with an appropiate scanner.
Monkfish1, nice to hear from you, I hope things are going well.Low oil pressure will specifically give a low oil oressure warning and a symbol of an oil can.
You say it went into limp mode.
The two are entirely unconnected. You have assumed the low oil level was the cause. It wasnt. Something else was. This will be stored in the memory and can be read with an appropiate scanner.
I have to sayI still miss my early morning drives from the North East down to your workshop to spend my overtime money……..happy days
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