Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[mickyboy123]

hi chaps.

is it a fairly common problem on a 2.2 for the exhaust manifold to be blowing or split.

[Steve B]

yes very common..mine seemed to be worst on start up and then faded 

[flyer 0712]

Yep very common indeed ...as stated cold it sounds but once warmed up goes quiet 

[mickyboy123]

funny you should say tha that's exactly what mine does.

what's the reason for this any ideas just out of interest.

and do you no any good sources to get a new 1 at a good price.?

[flyer 0712]

Dont know the reason.....maybe metal is crap and gets too hot,,,but i have had two that have suffered this fault....manifolds dont come up that often but last one i saw on ebay was £45....you could ask (ebay member.....omegas52......Nigel in nottingham who breaks around 20 omegas at any one time if he has one...that he yet has to advertise...worth a call.

[mickyboy123]

okay will do thanks for the info 

[Steve B]

Was up there last week..he as a couple of 2.2 omegas with HG gone.. So should have some manifolds ..But they all go the same way in the end...

[tunnie]

Manifold fine here, never had any issues.

[terry paget]

Reason they crack is they are cast iron. Cheap to make but after a large number of hot/cold cycles expanding and contracting they end up cracking. I once took one off and had a local workshop weld it up, he agreed to do it, but said he would not guarantee it and rather expected it would crack again. It did.
On the Rover 25 I have recently replaced the head gasket on the exhaust manifold is a better design. A steel plate that bolts to the head has curved pipes welded to it. This can expand and contract for ever and not crack.

[Steve B]

I remember well over a year ago on here there was a member who named a product that you fill the crack with and he sworn by it being a great product for this problem... Think he is a friend of mr EMD  mad mechanic.. not sure 

Wonder if it was blu-tac 

[mantamania]

When my 2.2 manifold cracked i could not find a secondhand one off of an omega.  My nearest breakers informed me that the same part was used on some Astra's and Vectra's.  The only difference is that one uses studs and nuts to attach to the downpipe, the other uses bolts but the manifold is the same part number. I got one from a Vectra

[Nick W]

Reason they crack is they are cast iron. Cheap to make but after a large number of hot/cold cycles expanding and contracting they end up cracking. I once took one off and had a local workshop weld it up, he agreed to do it, but said he would not guarantee it and rather expected it would crack again. It did.
On the Rover 25 I have recently replaced the head gasket on the exhaust manifold is a better design. A steel plate that bolts to the head has curved pipes welded to it. This can expand and contract for ever and not crack.

Welded manifolds are much less reliable than cast iron ones. They tend to crack worse and more often. Cast iron is an excellent material for an exhaust manifold, but the part does have to be designed correctly. Which is true of any part!

[mickyboy123]

Will prob go with a new 1 but having it checked first just incase the nuts have come loose