Oil leak at back of engine

[Midge]

Our Golf Mk4 1.6 auto (engine code BFQ) has just sprung a slight oil leak. It's dripping from the engine/transmission rear mounting as shown in the first photo and looked initially like it might be a drive shaft seal or something, but having a look further up the back of the engine (second photo), it's clear the actual source is much higher. i.e. I can see oil (circled in red) above the level of the exhaust manifold so my assumption would be one corner of the camshaft cover has sprung a leak. Any other possibilities?

I've always managed to swap the plugs with the inlet manifold in place (bit fiddly but possible). I think I will be able to remove the rear half of the manifold separately from the front half, in order to do whatever is needed, but are there are any seals that need replacing (over and above the camshaft cover seal of course if that is at fault). It is unlikely anyone has removed any of the inlet manifold in 20 years / 75K miles.

Thanks!

Leak 1.jpg

Leak 2a.jpg

[Midge]

Think I've found my problem just now. It looks like it's leaking from the offside end of the camshaft cover behind a bracket. The torx screw on the rear corner nearest the throttle body had actually worked loose somehow, so have tightened it up - and hoping that might be enough to sort it depending on what the seal is made of. All the screws I can get to are all tight so hoping it's just that one.



Leak 5.jpg

[Crasher]

The usual cause is the oil filler cap extension vent gasket failing or breather hose splitting, is the filler unit loose?

[Midge]

Hi Crasher - hope things are good with you.

I've checked around the filler and breather tubes and can find no trace of oil above the level of the camshaft cover seal. You can see below there is a very slight trace of oil below the seal towards the front bolt (which was tight), and the bracket on that side of the head which I suspect was hiding the leak, as you see a nice patch of oil on the head immediately below it. It was the back corner camshaft cover bolt that was loose and has now been tightened.

So I'm just mulling over whether I replace the seal as a precaution given its probably never been done in 20 years. Throttle body could do with a removal and proper clean anyway. As far as I can tell, the only gaskets I might need is if there is one where the fuel pipe secures to the throttle body, and presumably there is a throttle body to manifold gasket too. As far as I can tell, the two halves of the plastic manifold are a push fit together once you remove the two clips and two torx screws, so I'm assuming there are rubber seals in there too. Does this sound about right?

Thanks!



Leak 6.jpg

Leak 7.jpg

[Crasher]

The gasket is rubber but does perish and is easy to change. The VW part number is 06B 103 483 G
but at £38.04 is daft money, they are easy to buy for around £10 such as the Febi 33729

[Midge]

I put a big piece of cardboard under the car overnight and tightening that bolt does seem to have stopped the leak - but I've decided I'm going to go ahead and do the seal anyway, so thanks for the pointer Crasher - I've just bought one of those.

Whilst I was under the car the other day, this is the drain plug on the 01M auto box - and my bit of cardboard confirms there is the occasional (red) drip from this too. The sump is seriously crusty and I have a sneaking suspicion it might not seal - so have ordered a replacement sump, seal, filter etc. etc. Amongst the plastic bits that might break after 20 years, there is just one that doesn't seem to be readily available - and that is the screw out red oil level tube part number 096321363. Is there an issue with availability of those do you know? The 01M box seems to be very widely used across the VW range at that time.

Thanks.


Leak 3.jpg

[Crasher]

We had a 2015 Toerag V8 TDI come in where the engine sump bung was like that and we refused to drain the oil, went to order a new sump and it was on backorder!

[Midge]

We had a 2015 Toerag V8 TDI come in where the engine sump bung was like that and we refused to drain the oil, went to order a new sump and it was on backorder!

Aftermarket sumps for the 01M are very widely available - which rang alarm bells given the state of mine.

[Crasher]

You known the filling procedure?

[Midge]

You known the filling procedure?

Yes thanks Crasher - I have VCDS to check the ATF temp. Turns out the little oil level pipe 096321363 is like the proverbial rocking-horse droppings even in main-dealer world (have one on order via mine). I dare say it might unscrew OK - but I've had too many bits of plastic crumble in my hands not to try and get one just in case.