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Does engine oil need to be drained out before topping up?

Hi

I've recently brought a used car and there is oil that has already been topped up in September from the service history. I tend drive the car every weekend and will be checking the oil levels soon just wanted to check if its necessary to have the current oil drained out in the event i have to run out and purchase some oil to top up due to low levels?

Thanks in advance

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Reply 1
Original post by chosenone93
Hi

I've recently brought a used car and there is oil that has already been topped up in September from the service history. I tend drive the car every weekend and will be checking the oil levels soon just wanted to check if its necessary to have the current oil drained out in the event i have to run out and purchase some oil to top up due to low levels?

Thanks in advance

No. The oil is drained when it's changed, not when it's topped up.
As an aside, my cars moaning at me for an engine oil change and serivce, but its 18 months old and not even done 8k, can I ignore it for now? (I can't find the manual in case you're wondering) I'm not sure if changing the oil is something I can reasonably do myself or i'm best leaving to a service.
Reply 3
Original post by StriderHort
As an aside, my cars moaning at me for an engine oil change and serivce, but its 18 months old and not even done 8k, can I ignore it for now? (I can't find the manual in case you're wondering) I'm not sure if changing the oil is something I can reasonably do myself or i'm best leaving to a service.

Should have been changed at 12 months - was it?
Original post by IWMTom
Should have been changed at 12 months - was it?

Ah, no...:P go and get that done then? (I inheritied the car unexpectedly when it was just under a year old, so i doubt it had one before I got it)
Reply 5
Original post by StriderHort
Ah, no...:P go and get that done then? (I inheritied the car unexpectedly when it was just under a year old, so i doubt it had one before I got it)

That's your warranty gone then..
Original post by IWMTom
That's your warranty gone then..

V possibly, can't be helped i suppose, It is possible it had it done just before I got it, I just doubt it, although i'd have expected the service light have came on a LOT sooner if that was the case
Reply 7
Original post by StriderHort
V possibly, can't be helped i suppose, It is possible it had it done just before I got it, I just doubt it, although i'd have expected the service light have came on a LOT sooner if that was the case

What does your service book say.. and please don't tell me there isn't one or I might just have a breakdown.
Original post by IWMTom
No. The oil is drained when it's changed, not when it's topped up.


What would be the difference contextually? Technically it would be a different oil to the whats currently in when i top up. Sorry new to cars!
Reply 9
Original post by chosenone93
What would be the difference contextually? Technically it would be a different oil to the whats currently in when i top up. Sorry new to cars!


It might be a different brand but it should be the same (standardised) specification as recommended by the car maker.

The oil spec is in your manual - possibly 10W-30
Original post by Doonesbury
It might be a different brand but it should be the same (standardised) specification as recommended by the car maker.

The oil spec is in your manual - possibly 10W-30


Understood but a bit confused when you said its only drained when its changed instead of topped up. Not sure what the difference would be?
Reply 11
Original post by chosenone93
Understood but a bit confused when you said its only drained when its changed instead of topped up. Not sure what the difference would be?


An oil change is when the oil is drained out and new, fresh oil is used to replace it.

An oil top up is when the oil level gets low and more oil is added to get it to an adequate level, leaving the old oil in there.

If you want to check what’s best, look at the dipstick, it should be between the two markers and relatively “clean” looking. If it’s dark/dirty looking then it’s best to change the oil, if the oil looks okay but the levels a little low then you should just top it up.
Reply 12
Original post by chosenone93
Understood but a bit confused when you said its only drained when its changed instead of topped up. Not sure what the difference would be?


Eh? That was my first post! But I agree with the other posters that you just top it up, you don't drain the oil.
Original post by IWMTom
What does your service book say.. and please don't tell me there isn't one or I might just have a breakdown.

Yeah that's one of the bits I can't find :P I DO have it, it's just mislaid, but I already have that creeping feeling I didn't see any stamps in it.

Mildly annoying if the warranty is indeed away but honestly not a big priority to me right now, the owner unfortunately isn't going to be driving again.
Original post by Doonesbury
Eh? That was my first post! But I agree with the other posters that you just top it up, you don't drain the oil.


Ahh the question then is when would a change be needed as opposed to a top up?
Reply 15
Original post by chosenone93
Ahh the question then is when would a change be needed as opposed to a top up?

When you get your car serviced in line with the manufacturer's guidance.
Reply 16
Original post by Holly00
If it’s dark/dirty looking then it’s best to change the oil

Lol, if that's the case I should be changing my oil every day!
Reply 17
Original post by StriderHort
Yeah that's one of the bits I can't find :P I DO have it, it's just mislaid, but I already have that creeping feeling I didn't see any stamps in it.

Mildly annoying if the warranty is indeed away but honestly not a big priority to me right now, the owner unfortunately isn't going to be driving again.

Get it serviced ASAP.
Original post by Holly00
If it’s dark/dirty looking then it’s best to change the oil

Good luck if you're driving a diesel then... You'd be changing it out every other week, if not sooner.
Reply 19
Original post by TheMcSame
Good luck if you're driving a diesel then... You'd be changing it out every other week, if not sooner.

More like immediately.

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