Omega Owners Forum

Chat Area => General Car Chat => Topic started by: Webby the Bear on 10 September 2014, 19:52:34

Title: My plenum ate my 'O' ring....
Post by: Webby the Bear on 10 September 2014, 19:52:34
Athough this is prib the best thread title I've ever posted  ;D it is actually true.....

Found big vac leaks at TB to breather bridge and plenum to breather bridge and was pretty shocked to see the BB to plenum completely destroyed  :o im never vicious with stuff like that so it would appear the plenums eaten it away. wtf lol

In pic broken o ring..... two ''OE'' o rings were so thin no wonder I had a vac leak.... new ones on left. checked and no more idle issues *touch wood
(http://i1226.photobucket.com/albums/ee402/webbybear1/vacleak013_zpsb8b13bc4.jpg) (http://s1226.photobucket.com/user/webbybear1/media/vacleak013_zpsb8b13bc4.jpg.html)
Title: Re: My plenum ate my 'O' ring....
Post by: 4x4 on 10 September 2014, 20:17:44
 O dear webby  ;D
Title: Re: My plenum ate my 'O' ring....
Post by: dbug on 10 September 2014, 22:56:46
The TB to breather bridge o-rings are very thin and look similar to the 2 o-rings on the right of your pic.  The o-rings on the left look far to "thick" for TB to BBridge ??? ;)
Title: Re: My plenum ate my 'O' ring....
Post by: Webby the Bear on 11 September 2014, 09:47:34
The TB to breather bridge o-rings are very thin and look similar to the 2 o-rings on the right of your pic.  The o-rings on the left look far to "thick" for TB to BBridge ??? ;)

Spot on mate. The ones on the right are the 'OE' o rings......the ones causing a big vacuum leak (so bad that with carb cleaner sprayed I can almost stall the engine!)

So replaced with the thicker ones on the right (from a generic o ring set from Halfords) and now I have no vac leak. When I tightened up the TB bolts the thicker o ring was drawn in and is making a perfect seal now!  :y

also luckily I had a spare BB to plenum o ring as wasn't expecting this one to be destroyed  ::)
Title: Re: My plenum ate my 'O' ring....
Post by: Marks DTM Calib on 11 September 2014, 12:32:12
Something odd with your assembly then as I have never had an issue with fitting these (or damaged any during fitting  :y).

And from my experience, the larger O rings would not fit correctly into the recess  :y
Title: Re: My plenum ate my 'O' ring....
Post by: omega3000 on 11 September 2014, 12:54:21
What happened to the top hat  ???
Title: Re: My plenum ate my 'O' ring....
Post by: 05omegav6 on 11 September 2014, 13:08:10
What happened to the top hat  ???
They degrade over time. Hot oil vapour is pretty nasty stuff...
Title: Re: My plenum ate my 'O' ring....
Post by: Webby the Bear on 11 September 2014, 13:10:39
Something odd with your assembly then as I have never had an issue with fitting these (or damaged any during fitting  :y).

And from my experience, the larger O rings would not fit correctly into the recess  :y

I got to the stage where I can take plenum off in 10 mins now  8) so I can keep my eye on it. Honestly though, other than putting the top hat o ring on, putting it in place and then tightening the bolt snug I didn't and don't do anything odd with it. very strange!

I played about with different sizes of o ring. I eventually ended up taking a smaller diameter o ring and stretching it over (not to excess). and as said when I tightened the TB bolts it was drawn in :)

anyways no more vac leaks (checked with carb cleaner) and happy idle. so im happy :)
Title: Re: My plenum ate my 'O' ring....
Post by: Marks DTM Calib on 11 September 2014, 13:17:32
No need to remove plenum to do these.

My usual approach is a small wipe of lube over the rubbers so they just gently slide into place.
Title: Re: My plenum ate my 'O' ring....
Post by: Webby the Bear on 11 September 2014, 13:34:29
No need to remove plenum to do these.

My usual approach is a small wipe of lube over the rubbers so they just gently slide into place.

Thanks Mark.

I take it you angle the BB in to place then? I tried that once and it didn't go so well. I couldn't get the two pipes in enough to be able to push the round ''hat'' bit in to the plenum. and as I have the short plenum I had to remove it to get to the bottom TB bolts (as cam belt cover was in the way).
Title: Re: My plenum ate my 'O' ring....
Post by: 05omegav6 on 11 September 2014, 13:59:02
Undo the bagpipes, undo the clips on the four pipes at the back, undo four bolts on the plenum and lift off...

Then you can access everything...
Title: Re: My plenum ate my 'O' ring....
Post by: VXL V6 on 11 September 2014, 19:36:20
For the breather bridge it's just a case of four pipes off back, three torx bolts off the breather bridge on the extended plenums (one under breather ecotec cover) - or for non long nose plenums just the one under the ecotec cover - lift the bridge up gently from the rear and wiggle the whole assembly out of the top hat location and the throttle bodies....

Well that's what I do anyway!
 
Title: Re: My plenum ate my 'O' ring....
Post by: omega3000 on 11 September 2014, 19:41:52
Undo the bagpipes, undo the clips on the four pipes at the back, undo four bolts on the plenum and lift off...

Then you can access everything...

Those OE clips are a pita  ::) but yes thats the normal procedure  :)
Title: Re: My plenum ate my 'O' ring....
Post by: dbug on 11 September 2014, 23:54:52
Undo the bagpipes, undo the clips on the four pipes at the back, undo four bolts on the plenum and lift off...

Then you can access everything...

Those OE clips are a pita  ::) but yes thats the normal procedure  :)

Agreed - tie wraps do the same job ;)
Title: Re: My plenum ate my 'O' ring....
Post by: Webby the Bear on 12 September 2014, 09:40:27
cheers guys  :y
Title: Re: My plenum ate my 'O' ring....
Post by: omega3000 on 12 September 2014, 18:17:04
Undo the bagpipes, undo the clips on the four pipes at the back, undo four bolts on the plenum and lift off...

Then you can access everything...

Those OE clips are a pita  ::) but yes thats the normal procedure  :)

Agreed - tie wraps do the same job ;)

Just push mine on with no fasteners , never come off but im sure i would notice the hissing sid type noise if they did  ;D