Applying RTV to oil pan

[bayzoo]

Hi,

My oil pan has indents so I’m not sure if I should lay the bead in the indents or on the higher spots? Workshop manual says to use a liquid gasket.

Thanks

[Richard-D]

The higher spots and in a circle around the holes. The indents are there to give the flange rigidity so it doesn't bow down between the bolt holes.

Don't go silly with it, you're looking to minimise the amount that squeezes out into the sump

[E-bmw]

Richard-D said:

The higher spots and in a circle around the holes. The indents are there to give the flange rigidity so it doesn't bow down between the bolt holes.

Don't go silly with it, you're looking to minimise the amount that squeezes out into the sump

^^^ Wot 'e said.

Exactly the right answer.

I assume when you say RTV you are using RTV suitable for an engine, not bath sealant.

ETA.
You probably want a 3 or 4mm even bead all the way round the "high" section of the sump.

Edited by E-bmw on Friday 3rd April 08:21

[bayzoo]

E-bmw said:

^^^ Wot 'e said.

Exactly the right answer.

I assume when you say RTV you are using RTV suitable for an engine, not bath sealant.

ETA.
You probably want a 3 or 4mm even bead all the way round the "high" section of the sump.

Edited by E-bmw on Friday 3rd April 08:21

Thanks both

So on the inside or outside of the flange? I’m thinking nearer the outside (to the left of the indent) so it doesn’t going into the engine.

Yes I’m using an RTV for oil pans and engines, not the stuff for the bathroom 🤣

[E-bmw]

bayzoo said:

E-bmw said:

^^^ Wot 'e said.

Exactly the right answer.

I assume when you say RTV you are using RTV suitable for an engine, not bath sealant.

ETA.
You probably want a 3 or 4mm even bead all the way round the "high" section of the sump.

Edited by E-bmw on Friday 3rd April 08:21

Thanks both

So on the inside or outside of the flange? I m thinking nearer the outside (to the left of the indent) so it doesn t going into the engine.

Yes I m using an RTV for oil pans and engines, not the stuff for the bathroom ?

Both.

Like you were told in the first post.

Richard-D said:

The higher spots and in a circle around the holes.

[Richard-D]

Some tips...

Cleanliness is very important. Don't skimp on effort here as you don't want to be repeating the job. You need to scrape off all the old sealant. Ideally you should use a plastic scraper but it takes ages. A Stanley blade at a very shallow angle makes short work of the job but you do need to be careful, particularly on aluminium blocks.

After that, ideally green Scotchbrite to remove any remaining flecks then a wipe with brake cleaner to de-grease.

If you really want to make your life easy I would recommend this sealant:-

https://www.amazon.co.uk/W%C3%BCrth-Silicone-Super...

It's excellent, very easy to apply, comes in its own can with propellant so no need to use guns or squeezy tubes. It lasts ages in the can so you can use it for lots of jobs. The can works at any angle and is way more compact than a caulking gun for working underneath vehicles.

Unless there's a good reason not to, this is my 'go to' choice for any liquid gasket nowadays. I've never had an issue with this stuff and have used it in the worst environments for getting a good seal (really manky industrial diesels fitted to agricultural equipment, outdoors in bad weather).

-Clean both surfaces thoroughly.

-Apply sealant to one surface only

-Do up bolts evenly but lightly, leave for 10 minutes to start to cure (pay attention to tightening sequence or if you don't have it use a zig zag pattern to pull the sump up evenly).

-Apply final torque to bolts (pattern as above).

If you can you should then leave it to cure before filling with oil and starting. When pressed i have occasionally ignored this and have always got away with it but unless there's a team of guys desperate to harvest or the RADAR operator really needs the generator back up just leave it 'till tomorrow.