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Omega Help Area => Omega General Help => Topic started by: gbh on 28 December 2016, 11:19:26

Title: plenum vacuum
Post by: gbh on 28 December 2016, 11:19:26
Hi all,earlier in the year i changed the oil cooler and when everything was refitted i could here the plastic strip on the plenum sucking air,I took it back off to check that it was sealed but the problem persists. Does it require a new washer where it enters the plenum because thats where the sound is? and anyone have a part number? Have to say that this 2.6 is more livelier than my other and its an estate and the eml light just came on but maybe unrelated 0300 code
Title: Re: plenum vacuum
Post by: TheBoy on 28 December 2016, 11:30:13
Ignore my comment on other thread then, you clearly have an airleak.

No washers, so properly investigate. 9 times out of 10, its the black pipe worn through on bulkhead
Title: Re: plenum vacuum
Post by: gbh on 28 December 2016, 11:35:48
I thought I saw a washer where the plastic strip running down the centre of the plenum enters the plenum about halfway down. If you put your hand there you can here the hissing stop,i'll have to recheck and take photo when the weather warms up a bit
Title: Re: plenum vacuum
Post by: MonzaGSE on 28 December 2016, 11:45:17
I assume you are talking about the black plastic cover marked "Ecotec" on top of the plenum with the breather pipes inside? At least on the 2,5 and 3,0 there are a strangely shaped rubber gascet where it enters the plenum. Also two ordinary rubber o-rings where it enters throttle body. If you're a smoker cigarette smoke is great for finding vaccum leaks:)
Title: Re: plenum vacuum
Post by: gbh on 28 December 2016, 12:37:41
Hi there,Yes the ecotec strip is i believe where the air is being sucked in,about halfway down there is a part of this strip which pushes down into the plenum. When i heard it first of all i rechecked and there was an O ring on it,maybe that is not sealing correctly which may mean a new one,car has driven fine for the last few months until this long break coinciding with the eml light coming on.By the way my brother in law recently visited Norway on a cruise ship and really enjoyed it!!
Title: Re: plenum vacuum
Post by: Doctor Gollum on 28 December 2016, 13:34:07
There is indeed a seal there. Remove the cover and the strip, and carefully inspect the seal. Commonly referred to as the Top Hat by virtue of its shape. Be dealer only for a new one, assuming they are still available...
Title: Re: plenum vacuum
Post by: terry paget on 28 December 2016, 14:42:20
I've just been there. The top hat rubber seal is no longer available from Vauxhall dealers, or anywhere in the UK. In response to my query Doc Gollum found a reference in the USA, within the last month, offering them for about £5. I reused the old one, with a bit if grease, but mine was not damaged.
Fault code P0300 is random misfire, as displayed on my 2.6 last Saturday. Also displayed was P0306, misfire cylinder no. 6, which was right too.
Title: Re: plenum vacuum
Post by: terry paget on 28 December 2016, 15:07:58
http://www.omegaowners.com/forum/index.php?topic=138091.0