Leak (oil?) near fuel tank

blobslosak · Post by **blobslosak** » Mon Jun 01, 2020 12:53 am

Gonna find an Indy tomorrow for a look, but spotted a damp area on what I'm guessing is the fuel tank (black bit, not my car). Couldn't see an obvious route it had tracked from.

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Pretty sure it's oil but seems pretty far from the diff? I didn't sniff it but I think it would have been obvious if it were fuel.

Any thoughts?

Smartbear · Post by **Smartbear** » Mon Jun 01, 2020 7:49 am

Brake fluid maybe, i think a line runs above the tank?

Rob

-Tom- · Post by **-Tom-** » Mon Jun 01, 2020 8:06 am

Diff seals ...

PDJ · Post by **PDJ** » Mon Jun 01, 2020 10:17 am

Front diff seal or prop shaft u/j as it connects to the diff if it is grease like

Brake fluid would be more oil like

There is no other fluid of grease in the area other than petrol and that would evaporate that I can think of

blobslosak · Post by **blobslosak** » Mon Jun 01, 2020 12:31 pm

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Had a look this morning and it's defo oil, though quite sticky so been there a while I'd say. And location wise corresponds with the input to the diff. In history 2 years ago, invoice for service says 'topped up diff oil' so maybe from a previous leak, or it's still leaking. No drips on the driveway.

I'll get the seals looked at I think.

PDJ · Post by **PDJ** » Mon Jun 01, 2020 12:54 pm

Change the diff oil and monitor then over the winter have the diff out and serviced would be my suggestion.

blobslosak · Post by **blobslosak** » Mon Jun 01, 2020 1:09 pm

PDJ wrote: ↑Mon Jun 01, 2020 12:54 pm Change the diff oil and monitor then over the winter have the diff out and serviced would be my suggestion.

Any recommendation in Manchester/north west for that? Darren Wood being the obvious choice first.

PDJ · Post by **PDJ** » Mon Jun 01, 2020 1:15 pm

If you have a second car and can live with out it for a few days JC Racing in Thirsk North Yorks is the place to take it

John Cockburn 07812 202553

If it has done more than 80,000 miles it is due a service if you are lucky it will be just the easy bearings and seals if it is worn John will sort it out but there is a bit that needs to be spark eroded as BMW never intended it to be serviceable.

Matt.13 · Post by **Matt.13** » Mon Jun 01, 2020 3:16 pm

I have the same on my car but only a small amount, I was thinking diff seals I had the same on my old m5. I will addressed at the next service.
Let us know how you get on

blobslosak · Post by **blobslosak** » Mon Jun 01, 2020 3:33 pm

Matt.13 wrote: ↑Mon Jun 01, 2020 3:16 pm I have the same on my car but only a small amount, I was thinking diff seals I had the same on my old m5. I will addressed at the next service.
Let us know how you get on

Getting it looked at on Friday and new oil ordered, so will report back.

106k miles but no dodgy noises so hopefully can factor in the diff rebuild after the rod bearings and vanos refurb

I keep telling myself all this maintenance is cheaper than depreciation

enuff_zed · Post by **enuff_zed** » Mon Jun 01, 2020 3:43 pm

No doubt teaching you to suck eggs, but worth ensuring whoever looks at it cleans off all the old stuff, so you can see if it continues to leak.
May sound daft, but time is money, and some places wouldn't bother.

blobslosak · Post by **blobslosak** » Mon Jun 01, 2020 4:39 pm

enuff_zed wrote: ↑Mon Jun 01, 2020 3:43 pm No doubt teaching you to suck eggs, but worth ensuring whoever looks at it cleans off all the old stuff, so you can see if it continues to leak.
May sound daft, but time is money, and some places wouldn't bother.

I'm getting the new car new garage anxiety already

local BMW and Porsche specialist so hopefully all good but yeah will make sure I ask.

blobslosak · Post by **blobslosak** » Thu Jun 11, 2020 6:06 pm

Indy had a look. Looks like a leak from the Input shaft diff seal. Cleaned it all and topped it up for now, didn't need much.

mr wilks · Post by **mr wilks** » Thu Jun 11, 2020 6:18 pm

Diff seals on these are notorious for showing signs of "weeping" , i would only be concerned if you start seeing drops on garage floor or driveway from that area .

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