Sump Leak : Failing Gasket ? - The Unofficial BMW M5 Messageboard (m5board.com)

davidoli · 16th January 2008, 16:13

I have been talking to a fellow member today that has had an issue with the sump bolts on his S38B38 engine working loose . His mechanic advised him that this is a somewhat common occurence with these engines .

This has made me consider that perhaps all sump area leaks are not as a result of gasket failure .

Have any other members had experience of this ?

D

Lantz · 16th January 2008, 16:40

Yes, Ive had this issue. The bolts become loose and leaking results.

Quite a common occurence from what ive read on Swedish forums.

Apparently if you then tighten them the leak gets worse...

Lantz

farrell · 16th January 2008, 23:11

You cant avoid sump & timing cover leaks.
Nature of engine position canted over to fit under hood means
exhaust side of sump is perenially wet.
If people replace the sump gasket & apply the correct torque following best
practices for patterning the M6 fasteners, then the sump should not leak
every 12k miles.
Engine vibration will loosen low torque fasteners but
its less likely if the job is done properly.
Slap it together....do the job twice.
However, you cannot avoid old gasket technology.
Heat cycling & exposure to oil will embrittle & break off pieces of gasket.

Those who avoid or delay gasket repalcement, do so at their own risks.
There are equally concerning parts to inspect while sump is off after
the engine has been in service for a decade.
Any spare bolts found in sump when removed are not spares !

Cheers
Farrell

davidoli · 16th January 2008, 23:39

Quote:

Originally Posted by farrell

There are equally concerning parts to inspect while sump is off after
the engine has been in service for a decade.

Any spare bolts found in sump when removed are not spares !

ASBO · 17th January 2008, 10:02

Quote:

Originally Posted by Lantz

Yes, Ive had this issue. The bolts become loose and leaking results.

Quite a common occurence from what ive read on Swedish forums.

Apparently if you then tighten them the leak gets worse...

Lantz

You are quite right. The sump on mine has started to leak due to the the bolts falling off. I believe (and as has been said above) that as the gasket wears and gests brittle, the bolt tension reduces and they work loose, causing oil to drip all over the undertray.

Quite common and nowt too much too worry about.