Manifold blowing

Jatie_150

As above whats the best way to check this to see if its blowing ?

ambivect

First off... When its cold find yourself a built up area... wind your window down...boot it.... listen for a spitting noise. When it gets hot spitting noise has disappeared...heat has expanded manifold and sealed it. Remove heat shield (let it cool down first) and note crack down center of said manifold.. curse a little then ring LMF for replacement!!! £85 + p&p

Jatie_150

Thanks for that ....

But how the hell do I get the heat shield off :oops:

ambivect

Heatshield is easy to get off. Undo the 13mm nuts on the head and the 1 nut on the stud that fastens it to the manifold. You can do this with bonnet open working in engine bay. Manouvre the heatshield past the aircon pipe and remove...you will see straight away if manifold is cracked.

ambivect

One of the first signs I got that the manifold had cracked was an oily whiff in the cabin on cold start up...do you have that ??

Jatie_150

ambivect said:
One of the first signs I got that the manifold had cracked was an oily whiff in the cabin on cold start up...do you have that ??

Nope not that i have noticed only smell the b&h lol....

Thanks for the heads up on the removal for the heat shield . If I get time will remove it 2moro during my lunch break @ work 8)

Mark_Dj

Jatie 150 said:

But how the hell do I get the heat shield off :oops:

Check the How To Guide section and look at the Pre Cat Removal guide as that will show you how to remove the heat shield :wink:

Andy_Coupe

ambivect said:
First off... When its cold find yourself a built up area... wind your window down...boot it.... listen for a spitting noise. When it gets hot spitting noise has disappeared...heat has expanded manifold and sealed it. Remove heat shield (let it cool down first) and note crack down center of said manifold.. curse a little then ring LMF for replacement!!! £85 + p&p

Mine is doing this spitting noise at the moment, was told ether a crack in the manifold or the manfold gasket is leaking!

Mark_Dj

Try the gasket first, you may be able to see the crack if you remove the heat shield. Good luck

Andy_Coupe

Mark2.2 said:
Try the gasket first, you may be able to see the crack if you remove the heat shield. Good luck

after todat i have a few days off work so ill have a look to see whats what, then prob get it booked into the garage and get it sorted!

Mark_Dj

Sounds like a plan 😃 , you will lose power through any blowing in the exhaust and have fuel issues. It needs seeing to asap 🙂

Gazza

yea sure does mate.i thought mine was blowing but one of the studs on the manifold had had it and the nut came lose and this resulted in it blowing. 😃

Mark_Dj

Good result then 😃

Gazza

yea sure was i really dodnt wont to splash out on a new manifold,need some turbo alloys first 😃

Andy_Coupe

gazza1591 said:
yea sure does mate.i thought mine was blowing but one of the studs on the manifold had had it and the nut came lose and this resulted in it blowing. 😃

Also heard that a nut snaping is a common fault! Just hope the weather is good, hate working in the rain.

Mark_Dj

Andy CoupÃ© said:

gazza1591 said:
yea sure does mate.i thought mine was blowing but one of the studs on the manifold had had it and the nut came lose and this resulted in it blowing. 😃

Also heard that a nut snaping is a common fault! Just hope the weather is good, hate working in the rain.

That should not be a problem like the other types of engines as the manifold is at the rear out the way of the bad weather 😛 . My nuts came free easy enough when I did the pre cat mod 🙂

Gazza

im going to check mine every month as you said very easy to check and out of the weather 😃

gremlyng

Hi guys,

I've got a 2003 plate 2.2 Ecotec Astra G (sri) the inlet manifold has cracked a few times and a mate who now has vanished has welded it to keep me going for a bit. Unfortunatley the time has come where the cracks have opened again! arghhhh There's no ticking this time around but lots of blowing from under the bonnet! And terrible MPG 225 miles out of £45 of petrol! I just as well be running an M3 at this rate!

I'm fairly handy with a socket set and another mate of mine who is also into working on cars has offered to help replace the manifold with me! What I'm needing to know is how easy it is to do on the side of the road? Is there enough access to get a socket down behind the engine to remove the manifold? I have ramps, socket set, Torque wrench etc...

Do I need to apply sealing compound to the new gasget when fitting the new part? We've also got a torque wrench but I don't know what it should be set at when fitting the new manifold. (I just ordered a Haynes manual off Amazon for £12 delivered so that should give me the torque settings)

I'd really appreciate any help that I can be given on this. Vauxhall are charging me £136 including vat for a new manifold, gasaget, studs & nuts I thought this was fairly reasonable.

cheers
:thumbup:

Hareng

Sure its the inlet, they are plastic though can be welded.

Got a broken stud on exhaust manifold on mine half left in the alum head with usual symptoms of ticking when cold and blowing. EML been on for 12 months and passed MOT emissions and same economy as before 34 to 36 mpg.
225 mile aint that bad from £45 though depends upon circumstances.

gremlyng

£45 quid at £1.20 per ltr = 37.5 ltrs in total.

Divide the total amount Ltrs by 4.55 as there's 4.55 ltrs to a gallon = 8.24 gallons.

divide the mileage - 225 by 8.24 results in 27 MPG.

I put £10 in this morning and drove to work and back which is a 46 mile round trip and the petrol light is on and flashing again! I work that back at 25MPG

I guess petrol is on the increase so it's not the cars fault, but it is sounding very resonant like something is blowing from the front, bearing in mind the manifold has been welded twice and each time the MPG when really crap prior to welding. I'm fairly sure it's cracked again although there's no tick this time around, strange!!!

As to the precat, my car splutters on gearing down when slowing down and it sounds quite raspy anyway, not sure if thats because I dumped the middle box behind the cat for a long life steel straight pipe? I really wish I could clean the cat out and not suffer with the MOT. I'm guessing that would give me a few more BHP?

Most of the miles I cover are travelling between 40 - 60 mph due to the traffic on the roads in the morning, I've also been particularly careful since I felt the manifold was cracked again in an attempt to save some fuel. Out of interest is there any chance that the cat could have broken up inside and that it could be casuing a block in the pipe resulting in more fuel intake?