Changing engine oil - pump it out, or let it drain?

[i know nothing]

I'm looking to change the engine oil and filter myself.

I don't really have the facilities to drain the oil (need to jack car up and remove under tray to gain access to sump drain plug). What of course would be easier, is to buy one of these manual pumps, remove the dispstick and pump it out.

I worry that if I pump it out I will be leaving contaminants behind at the bottom of the sump, whereas a drain would (potentially) flush these contaminants out. I suppose they might be pumped out, but you'd never really know. I guess the oil filter should really catch contaminants anyway.

This is something I would do twice yearly.

What are the pro's and con's?

 

[Iamzod]

Why can't you remove the undertray?

I do it on my lowered ST220, whilst I do have several jacks & stands i just run it up some wooden blocks so I can get under it without messing around.

 

[i know nothing]

Why can't you remove the undertray?

I could, but...

...whilst I do have several jacks & stands i just run it up some wooden blocks so I can get under it without messing around.

Don't have any of that gear, would need to buy it.

 

[Akagi]

What car is it? Surely there is an access hole, or a small removable panel, to give access to the sump plug? I find it hard to believe they would make you remove the entire undertray to drain the oil...

Also, its about the easiest job you can do to a car, I have read your username and all but, come on, gotta start somewhere!

I've been temopted by the sucky sucky oil pumpy devices, but I've not bought one because I want the old oil to wash out any contaminents, debris, etc, that might be in the bottom of the sump pan.

I might convert though if the replies in this thread convince me.

 

[i know nothing]

What car is it? Surely there is an access hole, or a small removable panel, to give access to the sump plug? I find it hard to believe they would make you remove the entire undertray to drain the oil...

2007 Jaguar XJ, it does require one of the undertrays to be removed, there is no access hole etc.

Also, its about the easiest job you can do to a car, I have read your username and all but, come on, gotta start somewhere!

I'm not daunted by the prospect of doing an oil/filter change, used to do it years ago as a young man with all my cars, just haven't done it for about 10 years (got lazy!). Wondering if pumping the oil out would just be easier and as effective.

 

[Iamzod]

I could, but...

Don't have any of that gear, would need to buy it.

Blocks of wood?

Just pick up from B&Q for a fiver, cut it down to size & run your car up it.

You don't need to jack it up, I don't with my car and it's way lower than an XJ.

 

[i know nothing]

So pumping is not recommended it would appear? An old fashioned drain the sump is the best way?

 

[p1RATE]

Im quite interested to know this too. I was told about a wondrous device that would pump the oil from the dip stick tube by someone from a classic car club i use to be a a part of. It did sound a lot easier and tbh I would probably change my oil a lot sooner if it was as easy as that.

 

[Phemo]

I’ve done it before. Had an electric oil pump which I used on two cars - an S-Max and a Fiesta. To be fair I did get more or less the same amount of oil out compared to draining via the sump plug.

Unfortunately the pump died and I just never got round to buying another one so I’ve just stuck with the old fashioned method ever since.

 

[jpaul]

if you extract the oil. hot, is there so much residue left in the sump ? - if, pumps, tolerate the high temp.

I've always drained from beneath though, a few minutes after a run-out.
channelling the oil into its urinal, avoiding dropping the bolt/cross-threading/overfilling being the main concerns

 

[Terminal_Boy]

Don’t forget a new crush seal washer if removing the drain plug and disposable gloves.

 

[hugobosslives]

The short answer is that pumping the oil out is absolutely fine. Yes you will get very slightly less out (50ml) but it does not matter much. The important bit is you keep up with the oil change interval. 50ml of 1year old oil is really not an issue in 5L.

Bear in mind you can only do this on cars with a dipstick. It doesn't work if you go through the oil fill cap.

 

[HoneyBadger]

I use the pump method purely for convenience and it works fine. As mention you get a tiny, tiny amount left but not enough to be a problem. Our car has 5 litres and I measured it by filling up old coke bottles. Filled up almost 5 litres so that was good enough for me.

 

[jsmoke]

What about oil filter?

 

[HoneyBadger]

What about oil filter?

On my car it’s a cartridge at top front of the engine so easily accessible from under the bonnet.

 

[Finglonga]

So pumping is not recommended it would appear? An old fashioned drain the sump is the best way?

Old school people. Vacuum oil removers are great, I have done it for years and the first time I did it I dropped the sump plug out and got less than a teaspoon of oil out. Only reason not to choose to do it s on cars with the filter under the engine where you need to get under there anyway.

 

[Nasher]

You will always have a bit of old oil left. But the new oil will dilute it to a point where it's a non issue.

 

[i know nothing]

What about oil filter?

On my car it’s a cartridge at top front of the engine so easily accessible from under the bonnet.

Only reason not to choose to do it s on cars with the filter under the engine where you need to get under there anyway.

I should have considered the location of the oil filter. Mine is like HoneyBadgers, easily accessible from under the bonnet. The only reason to remove the main undertray would be to get at the drain plug.

 

[MrRockliffe]

Don't have any of that gear, would need to buy it.

A basic heavy duty car ramp, which is easier and less fiddly than a load of jacks, and safer, will cost about £35 if you have the place to store them. Makes the whole process significantly easier, as you can then see what you’re doing.

 

[i know nothing]

As mention you get a tiny, tiny amount left but not enough to be a problem. Our car has 5 litres and I measured it by filling up old coke bottles. Filled up almost 5 litres so that was good enough for me.

I have done it for years and the first time I did it I dropped the sump plug out and got less than a teaspoon of oil out.

You will always have a bit of old oil left. But the new oil will dilute it to a point where it's a non issue.

My engine has a 6.6litre capacity, I think as you all point out, there would be too little left to make a difference once the new oil is added.

Anybody care to suggest a decent pump? I've heard good things about the Pela 6000 oil pump.