Oil leak at rear of 2ltr

[NSharpley]

Now I know this is probably one of the oldest and most talked about topics but ...

I had an oil leak at the rear of the engine and was planning on an engine bay cleanup so decided to pull the engine out and do the common seals / gaskets whilst doing the engine bay work.

Replaced the sum gasket, rear main seal and the gasket for the oil galley cover plate.

Engine back in and ran up to temp ... everything seems ok.

Not only do I still have an oil leak (granted it isnt anywhere near as bad) but the leak is constant.   The engine hasnt run now for a couple of weeks and still the oil drips.

I can wipe away the drips and then the next day, more drips.

What area at the back has oil sitting right next to a gasket or seal when the car is stationery?

All of the oil shouldve by now drained back into the sump.

The drips appear on the rear sump bolts.   

I have re-tightened those, although they werent loose.

But where is this oil coming from??

I can understand if it were the rear main or the sump, when the engine is running ... but this just keeps on dripping.

Its definitely coming from inside the bell housing so isnt cam cover or anything above ...

Suggestions?

[rowan_bris]

Did you replaces the wicks between the rear main cap and block?

[NSharpley]

I didnt but there isnt any oil sitting against those when the car is stationary so it shouldnt be leaking from there when the car is sitting.

Running, sure ... but not stationary.

[bonno]

I am with Rowan, also known as cigarette seal. Also I have a post from Alfa Romeo BB on this issue.
https://www.alfabb.com/bb/forums/engine-repair-diagnostics-rebuilding/649754-cigarette-seal-variations-2.html

[NSharpley]

Yeah, I am very familiar with these seals but my point is ... the engine is constantly leaking oil whilst NOT running.

There is no oil actively near those cigarette seals when the engine is off so there is no way the leak could be coming from there.

My suspicion is that the car isnt sitting level at the moment because its on stands and the front is higher than normal.

So it stands to reason that the oil is actually resting up against the rear portion of the gasket and seeping through.

[bonno]

To prove your theory and the sump bolts have been torqued correctly, I would try and nip up all bolts another 1/2 to 1 turn and see if it fixes the leak. If not, you may need to investigate further such as possible cracks, with focus around leak area.

[carlo rossi]

Sorry mine did the same ,the guy cut the cigarette seals too short !
talk to Rob at brookvale
bit of a guru with this
I went through half a litre a week just standing
I think the oil drips down from the head when stationary

[giulia_veloce]

Oil can leak from the 2 middle rear sump bolts
Remove bolts,,clean bolts and holes with brake cleaner,,and use ultra grey on threads and washer and install.
Also on Alfetta engines,,there is an Oil bolt on the rear of the engine that can come loose and leak.
Those 2 rear head Allen key nuts leak,,especially exhaust side,so make sure they are tight.
Cigarette seals are a common leak area (ask Carlo).
I Modify them and use the Alfa Special tool to insert them .
The rear main seal is Not normally the problem,,its the cigarette seals.,,2 rear centre sump bolts,rear head allen nuts etc.'

NSharpley....clean the area with brake cleaner,,compressed air to dry it,,and have another look.

[NSharpley]

I reckon you're on it with those rear sump bolts.

Mine only had oil on the one sump bolt so I just gave it a 1/2 turn, clean up any oil and left it overnight.

No sign of further leaks.

Will leave it for another 24 hours and check again.

Thanks for the tip.

[NSharpley]

Well ... in the interests of closure ... I did the cigarette seals.

Ran it up to temp ... no leaks.

[LukeC]

Haven't used the supplied cigarette seals for years... Chucked them in the bin! Eventually they go hard, shrink and leak.

Permatex Grey is your friend here. There is a reason that later V6 engines went this way.

You can build an almost oil leak free Nord engine using a few mods and modern sealing compounds.

[NSharpley]

New update.

Drove the car a decent distance today and it leaked like an oil waterfall!!

I made the decision to not use any gasket compounds on the sump gasket other than simple Permatex.

I think once the car got going and the oil was thrashing around against the back of the sump its leaked out.

And perhaps the cigarette seals havent seated properly thereby creating a gap between the bearing cap and the sump.

So, sump off again.  Another sump gasket.

I think this time Im going to remove the newly installed cigarette seals, use the Permatex Grey that has been suggested in this thread in their place then use some Silastic or similar with the sump gasket at the rear.

Anyone got anything else to create a bulletproof leak-free 2ltr?

[giulia_veloce]

Ask Carlo above

If the cigarette seals are Modified and the Special Alfa Installation tool to fit them is used,,usually No leaks
I have never needed to use silicon or ultra Grey etc by itself cause I don't have a problem.

Lots of options
Ask Carlo if his leaks

[bonno]

As per the photo on wicks/cigarette seal in my earlier post above, it is imperative that the wiks/cigarette seals need to be trimmed flush with the block (must not protrude above or below) as this will cause the pan gasket not to seal on assembly (reference Haynes Workshop manual P44 figures 17.11d & e).

[NSharpley]

As per the photo on wicks/cigarette seal in my earlier post above, it is imperative that the wiks/cigarette seals need to be trimmed flush with the block (must not protrude above or below) as this will cause the pan gasket not to seal on assembly (reference Haynes Workshop manual P44 figures 17.11d & e).

Have read that yes ... but ... the original Alfa recommendation is not to cut them.   Mine did protrude, perhaps 2 - 3mm, but as per the Alfa guidlines the sump compresses them into the slot for a correct seal.

Saying that ... before I did the seal I had an active leak, that being persistent even when the car was stationary and not running.   I no longer have that leak so I feel like the cigarette seals are doing their job but the protrusion is, as you say, causing the sump not to seal.   So on repeated accelerations the oil is pushed to the back of the sump and seaps out that poor sump gasket seal.

I think my best approach is to:

1. remove sump, remove cigarette seals and follow Carlo's suggestion of rounding the top of the seals, inserting silicone and then pushing the seals back in.   Cut off the protrusion up to about 1mm exposed.   Replace sump with some silastic as the back edge.

2. just remove the sump, cut off any protruding cigarette seal then replace sump with some silicone along the back edge.

The lazy option is number 2.   But I am confident the issue is simply the sump sealing to the block, or lack thereof.

Thanks to all for the comments.