Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: MAMV6 on 04 December 2022, 17:37:08

Title: Cleaning Crankcase Breather Setup & O-Ring parts availability
Post by: MAMV6 on 04 December 2022, 17:37:08

Hi all, looking to tap into the OOF collective knowledge.

I am planning to clean the crankcase breather setup as per the excellent detailed guide elsewhere on this site, to try and tackle the persistent oil leak that my 2002 2.6 V6 has.

I understand I should need (depending on the state of the originals when they come out):


Breather bridge to plenum "tophat" seal 1 required - 90467543

Breather bridge to throttle O ring 2 off required (4 of on extended plenum's) - 90500983 - I already have 3 of these original GM, just need 1 more.

Inlet to Plenum O-rings - 9118135 - 6 required


Does anyone know where I can get replacements for these? Have tried Autovaux, eBay, multiple internet searches, my local friendly motor factor etc. I think someone mentioned a couple of years ago on this forum you could get parts such as the tophat seal from the USA? Would that be from the likes of RockAuto - as far as I can tell they only have the set of 6 o-rings (9118135) up for £35.

At the moment there is also an original new/old stock tophat seal in Germany for £59 plus postage?  :-\

Any pointers or hints gratefully received.

Title: Re: Cleaning Crankcase Breather Setup & O-Ring parts availability
Post by: Doctor Gollum on 04 December 2022, 17:54:35

Genuine GM part sales. Not the Peugeot BS we have to put up with here.

Give them the part numbers from the guides and expect them to have changed. If the parts are available, they will be able to get them, but you might not like the price, but that's the cost of being able to get genuine, current parts when your local VX dealer can only tell you that everything is NLS.

Title: Re: Cleaning Crankcase Breather Setup & O-Ring parts availability
Post by: Migv6 le Frog Fan on 04 December 2022, 21:23:55

Unlikely you will need the 6 plenum . breather bridge O rings. They can be reused many times. As can the two small O RINGS.
So can the top hat actually, but they can get damaged on removal / refitting.
Best to take the plenum off and have a look. Chances are you wont need any of them.

Title: Re: Cleaning Crankcase Breather Setup & O-Ring parts availability
Post by: biggriffin on 04 December 2022, 22:24:55

Silicone grease is your friend. Carefully remove all old seals,after spraying them with silicone spray, when refitting coat seals with silicone grease.

Title: Re: Cleaning Crankcase Breather Setup & O-Ring parts availability
Post by: MAMV6 on 07 December 2022, 17:02:57

Thanks all for your advice.

I think I'm going to crack on and open it up on the hope that I can reuse all or most of the seals, and use the silicone spray/grease to aid that.

I've got the GM parts number so will give them a bell too.

Thanks again.

Title: Re: Cleaning Crankcase Breather Setup & O-Ring parts availability
Post by: Kevin Wood on 08 December 2022, 07:08:18

Quote from: biggriffin on 04 December 2022, 22:24:55

Silicone grease is your friend. Carefully remove all old seals,after spraying them with silicone spray, when refitting coat seals with silicone grease.

You need to avoid silicone around the air intake as it will poison the lambda sensors.

Title: Re: Cleaning Crankcase Breather Setup & O-Ring parts availability
Post by: MAMV6 on 08 December 2022, 17:44:47

Ok, thanks for that additional advice Kevin Wood. Is that a caution against using silicone spray/grease at all or just being very careful with how much you use to help clean and reinstall these seals?

Title: Re: Cleaning Crankcase Breather Setup & O-Ring parts availability
Post by: Doctor Gollum on 08 December 2022, 19:20:58

Just use a wipe of clean engine oil. No silicon.