Tricks to breaking seal on Oil Sump Cover?

I've had success with a plastic scraper/spatula + a rubber mallet.

 

Go slow and evenly around the surface .... do not want to flex anything.

 

Just removed my two pans a couple days ago; they were gooped up with sealer and came off pretty easily. 1. Shave off any protruding sealer and gasket around the perimeter with a knife and wet the exposed fiber with Permatex gasket remover a couple of times and let sit a few minutes. 2. Reinstall two opposing nuts half way so if pan comes off quickly it doesn't drop to the floor. 3. I didn't have a thin-enough and stiff-enough plastic scraper, so used a 1" wood chisel (taper side down), very lightly tapping it into the center of the gasket material (no metal to metal) around each corner until one corner gave way, then easily worked my way around. I also periodically rapped the pan sides with a rubber mallet although not sure this had any benefit.

Thinking about next time, while no sealer is required, I plan on using a very thin ribbon of Hondabond (routed on the inside of the bolt holes) to ensure no drips or bolt hole weeping. Also got a new set of Belleville disc washers (McMaster 96445K25: 6.2mmID) given the low torque spec. (Both tips from FChat.)

 

As noted, thin blade and gentleness!

Frankly, the problem you are having is one of the reasons I do not use the popular silicone gasket sealers, or any other sealer that cures and becomes 'glue' to deal with on the next disassembly. Yes, ou can grease one surface before applying the silicone to the other but why add an extra step? The other issue with silicone is not the fault of the silicone but the fact that many people apply too much and the squeeze-out is both unsightly and hazardous to engine internal oil passages.

For years I have been using Permatex Motoseal which is a non-silicone, non hardening sealer. https://www.permatex.com/products/gasketing/gasket-makers/permatex-motoseal-1-ultimate-gasket-maker-grey/ I've used it on everything from motos to Detroit Diesel 2 stroke marine engines and like it a lot. Also used a lot of Permatex aviation sealant #3 on large gasket surfaces on the diesels. It also works well though somewhat messier to apply! https://www.permatex.com/products/gasketing/gasket-sealants/permatex-aviation-form-a-gasket-no-3-sealant-liquid/ NO, I have association with Permatex!

FWIW...sealers are not required for every gasket though many folks use it "automatically." If the mating surfaces are good/true only the gasket should be necessary. In the professional side of things, the MOST IMPORTANT thing is to avoid call-backs so 'gluing' the assemblies together with silicone is not an issue for them. If they have to remove the part(s) at the next service or whatever, they're just going to charge for the extra work removing might entail (which the hourly figure/price for the work most likely includes anyway) !

But if YOU are doing your own work, it's much easier to deal with assemblies that are NOT glued together.

 

I suspect you will eventually find your oil sump gasket is not leaking. Often it is the cam seals, shift seal, dipstick tube or other spot leaking. Oil runs down hill and winds up on the sump with oil drops forming on each stud. It’s just the lowest point but not the origination of the leak.
good luck.

 

Years ago i managed to change the sump gasket on my 3.2 mondial by just dropping the sump pan without taking the dip stick tube out. I did not realise you had to remove the tube in order to get the pan off. Now have the pan joint broken and the pan has about 1/2 gap to the sump but will not come off. I ended up taking the sump pan studs out and after cleaning off the old joint i managed to work the new joint into place somehow. After bolting it all up with no sealant it was leak free for the next 15 years before we parted company. Desperate times call for desperate measures as no chance getting to dealership.

 

Just for clarification - Permatex has an Ultra Grey silicone sealer as well as the Ultimate Motoseal Grey, which is solvent-based. So some confusion is possible.

 

Concerning the nuts and studs “leaking”. The studs on my ‘82 308i are blind holes, impossible to leak. The problem is not sealing the gasket correctly. If sealed correctly the fluid would never leak around the studs. I have done this twice. Both times clean dry surfaces and nothing on the gasket, yes dry green gaskets. Evenly torque to spec. Now 5 years and no leaks using mobile 1 synthetic 15w50 the time before same result with valvoline vr1 oil. Just saying......

 

Mine leaked with Mobil 1, has also leaked with VR1.

 

Mine too no leaks for 7 years using Redline Synthetic oil and using the same nuts and washers. Like you said clean and dry, torque properly, and use good sealant.

 

GT, I guess I could have done it without any sealant but I just want an extra insurance so this is what I use really great stuff and if not this I use the Hondabond that also works great. Image Unavailable, Please Login

 

I agree with your thought that overtightening may have warped the sealing surface. That's an extremely common occurrence, compounded by the fact that most people's first response to a leak is to tighten the fasteners, further warping the surfae..

 

Surface

 

FWIW when re building the motor on my ‘82 308GTSi on any “green” gaskets I have not used any sealant. Valve covers, block front cover, sump pans, oil filter mount, water pump..... just saying......