Omega Owners Forum

Chat Area => General Car Chat => Topic started by: Steve B on 02 August 2014, 00:09:48

Title: 2.2 Exhaust manifolds
Post by: Steve B on 02 August 2014, 00:09:48
So do they mainly crack in the same place.. :-\
Title: Re: 2.2 Exhaust manifolds
Post by: Steve B on 02 August 2014, 01:03:29
This is the intended rapair method .

1. Cut V in Crack
2.Put manifold in industrial oven and heat up to very high temp
3.Weld (not sure which method yet..Looking for input)But it wont be gas..
4.Let cool naturally.

The reason for heating up the manifold is to stop it cracking again when cooling..(ie;Cold meeting hot)

Any input welcome  :y
Title: Re: 2.2 Exhaust manifolds
Post by: 4x4 on 02 August 2014, 06:44:21
I did find some new 1s on ebay for around £60ish a while back,frontera 2.2 also suffer with cracked manifolds.
Title: Re: 2.2 Exhaust manifolds
Post by: steve6367 on 02 August 2014, 07:05:24
I don't think any weld will be a long term fix and as above you can buy for around £60.
Title: Re: 2.2 Exhaust manifolds
Post by: PhilRich on 02 August 2014, 09:21:07
Afaik, the Frontera 2.2 manifold is identical as is an Astra variant (not sure which one :-[) albeit with different part numbers :-\
I had mine welded by a local Engineering workshop using State of the Art techniques but was warned beforehand that there were no guarantees & sure enough it cracked on first run after refitting! It looks like a Design fault/Quality Control issue as the castings are like swiss cheese :o
Title: Re: 2.2 Exhaust manifolds
Post by: flyer 0712 on 02 August 2014, 10:25:01
Quite common on 2.2......they can be welded as stated  :y
Title: Re: 2.2 Exhaust manifolds
Post by: Steve B on 02 August 2014, 11:55:24
Afaik, the Frontera 2.2 manifold is identical as is an Astra variant (not sure which one :-[) albeit with different part numbers :-\
I had mine welded by a local Engineering workshop using State of the Art techniques but was warned beforehand that there were no guarantees & sure enough it cracked on first run after refitting! It looks like a Design fault/Quality Control issue as the castings are like swiss cheese :o
Didit go in the same place  ie; did the weld fail  :-\
Title: Re: 2.2 Exhaust manifolds
Post by: PhilRich on 02 August 2014, 17:13:57
Afaik, the Frontera 2.2 manifold is identical as is an Astra variant (not sure which one :-[) albeit with different part numbers :-\
I had mine welded by a local Engineering workshop using State of the Art techniques but was warned beforehand that there were no guarantees & sure enough it cracked on first run after refitting! It looks like a Design fault/Quality Control issue as the castings are like swiss cheese :o
Didit go in the same place  ie; did the weld fail  :-\
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Yes & Yes :'(
Title: Re: 2.2 Exhaust manifolds
Post by: Steve B on 03 August 2014, 02:10:20
I don't think any weld will be a long term fix and as above you can buy for around £60.
That is my path of thought .Fill the gap for a long term fix.Ok i could go down the scrappy and pull one off another car. then turn it over and see it is also cracked...I could go and buy one that is not cracked..But in time it is going to crack..

So my thought was..
 can the crack be..Filled/welded.
Why did it break in the first place.... Stress/Being cooled very quick by water/cold weather.  :-\ :-\
Title: Re: 2.2 Exhaust manifolds
Post by: 4x4 on 03 August 2014, 12:18:53
The only way to stop it will be to get a 4-2-1 manifold made in stainless,it has been done ....
Title: Re: 2.2 Exhaust manifolds
Post by: Andy B on 03 August 2014, 12:23:50
This is the intended rapair method .

1. Cut V in Crack
2.Put manifold in industrial oven and heat up to very high temp
3.Weld (not sure which method yet..Looking for input)But it wont be gas..
4.Let cool naturally.

The reason for heating up the manifold is to stop it cracking again when cooling..(ie;Cold meeting hot)

Any input welcome  :y

In the past when welding cast, I've done as you have said ie heat the job up to prevent the item from cracking along side the new weld, but I'd have access to oxyacetylene to do the heating up ........ I've used a cast rod ie ARC/MMA or a rod intended for dissimilar metals.   
Title: Re: 2.2 Exhaust manifolds
Post by: omega3000 on 03 August 2014, 15:08:00
The only way to stop it will be to get a 4-2-1 manifold made in stainless,it has been done ....

  :y