M40 sump swap

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boiliebasher
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Sun Nov 10, 2019 4:46 pm

So today I swapped out the sump on my M40 powered E30 316i

Don't know if there's a "how to" on the forum but thought I'd write up a quick guide.
It's a very straight forward job and only basic tools are required.

*I hold no responsibility for damage or injury which may occur in working on your own car and if in doubt, please take it to your nearest reputable car garage*


My original sump had taken a hit or two in the past and there where micro fractures visible but luckily, not leaking. But I knew it was a ticking time bomb so had to be dealt with sooner or later....

First of all jack up front end of the car. I used ramps as it's quicker and easier.

Drain all oil from sump via the 17mm hex sump bolt into a suitable container.

Next you will see a series of M6 bolts (10mm socket) There are 16 in total. Undo them all and gently drop the sump down.

You will then see something that looks like this:

IMG_20191110_131435584.jpg
Now if there are any remains of the old gasket, carefully scrape away at it until there is a clean surface like above. I used a Stanley blade and a dap of petrol to soften up the old remaining gasket material.

But be CAREFUL, and take your time aluminium is a very soft metal and is easily scored/ damaged.

This is the old sump I removed against a good replacement one. My mate broke an M40 engine a while back and he kindly gave me this one as it was it great shape.

IMG_20191110_131134626.jpg
Again you want make sure both the mating surfaces are as clean as possible. I cleaned the replacement sump out with petrol and a toothbrush to get it nice and clean.

Then you'll need a new gasket:
IMG_20191110_131156242.jpg

I personally found it easier to put the new gasket on to the sump mating surface before I put it in place. Like this:

IMG_20191110_131552323.jpg
Then refit your new lovely clean shiney sump and gasket back onto the car. It helps if you can get a couple of bolts started first then it will hold the sump in place for you whilst you fit the rest.

Make sure the gasket sits correctly and everything is nice and flush.

I took the time to clean up the old bolts too (my OCD kicked in) but that's just me.

Torque all 16 bolts back up (no idea what official NM or lbs/ft setting) but I torqued them up evenly until they just felt snug. They really don't need to be done up ridiculously tight and you'll just end up mashing the gasket up too much if you do.

It should now look like this:

IMG_20191110_134924340.jpg

And that's pretty much it! Easy peasy!! Don't forget to tighten up sump bolt and replace the oil.
I changed the oil filter at the same time as it made sense to do it all at once and put some nice fresh oil at the same time. The box that contains the new oil filter usually comes with all the seals needed for the oil filter housing and bolt (13mm socket), as well as the copper washer for the sump bolt.
Last edited by boiliebasher on Sun Nov 10, 2019 11:13 pm, edited 3 times in total.
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Aly-g
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Sun Nov 10, 2019 10:48 pm

good write up , a job i think i'm going to have to do looking at the oil slick on my drive...! thanks,

Allan
its not growing old that stops you playing.....its when you stop playing that makes you grow old.....
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boiliebasher
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Sun Nov 10, 2019 11:00 pm

Aly-g wrote:
Sun Nov 10, 2019 10:48 pm
good write up , a job i think i'm going to have to do looking at the oil slick on my drive...! thanks,

Allan
Hope it helps! Pretty straight forward job to be honest. I spent far more time scraping off the old gasket material and cleaning it all up again than actually the time it took me taking the old sump off and bolting the new one up!
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Brianmoooore
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Sun Nov 10, 2019 11:25 pm

Bit late now, but did you check the torque of the bolts for the upper half of the sump? There are a few that are inside the sump, and can only be reached when the lower sump is off. It's not at all unusual to find one or more of these bolts lying loose in the bottom of the lower sump when you remove it.
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boiliebasher
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Sun Nov 10, 2019 11:53 pm

Brianmoooore wrote:
Sun Nov 10, 2019 11:25 pm
Bit late now, but did you check the torque of the bolts for the upper half of the sump? There are a few that are inside the sump, and can only be reached when the lower sump is off. It's not at all unusual to find one or more of these bolts lying loose in the bottom of the lower sump when you remove it.
Funny you should say that. There was a bolt lose and I checked them all whilst I was in there. Didn't have any loctite, but just checked they were all nice and secure.
rix313
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Mon Nov 11, 2019 3:11 am

I’ve got quite good at doing this as I frequently knock mine when racing 🤦🏻‍♂️
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