Thread: Exhaust Manifold bellows cracked

If you are wondering how I found this leak......
On start up with bonnet open I could hear this huffing sound. After the engine came up to temp it vanished. Been here before so I know it was a small crack somewhere and when expansion occurs blocks it up (well that's my theory).
When I removed the manifold I checked the flanges for blow past - zip. But that little brass stud that is the outer heat shield attachment point (back one in my case) had black soot on it. AND the inside of the heat shield also showed signs of soot (wire woven pattern). Sort of conclusive.
Any case, here are some photo's.

Hi Dave
the design of the exhaust headers probably requires the flex joint to enable the "system" to absorb expansion and vibration etc. and thereby prevent over stressing the studs connecting the manifold to the head or cracking of the manifold elsewhere. The flex joint on mine looks like this Range Rover P38 Exhaust Manifold Left Hand Side 4 0 4 6 Tublar Stainless Steel | eBay
I'd replace the flex joint rather than go "solid"...

This is a great post. Informative.

Mine is the same as Hoges's, and I have had a crack in it too. Its hard to seal up, and I ended up replacing the exhaust manifold. The leak causes the O2 sensor to get confused.

Note on coating, our headers are stainless steel fyi. Also, I believe that those shields, after wrestling with them many times are very effective. I bought exhaust wrap, but putting it on those headers looked too difficult.

I was going to post last night that mine had the convoluted expansion piece too.

Admittantly this design header doesn't loosen off the exhaust bolts like the cast headers did - maybe that's the reason for the expansion bit.

I imagine on the header of a petrol engine would be the toughest place for that type of expansion joint though. I'd you can't get any better quality ones you may be up for new exhaust manifolds. Linrover had some cheap ones a while ago - even if they're cracked in other places, they're very easy to weld up.

Hi

Sounds like something worth checking for sure

Steve

Just to clarify - the bellows shown in my photo's are aftermarket. The original bellows were true Land Rover as in the ebay photo. I tried welding the crack in the bellow unit as a temp repair - a REAL long shot I have to admit. It's paper thin. So I had a shop weld this set in (cost a heap) but it hasn't gone the distance - probably 15k which is pretty horrible. Well I dropped into a place tonight and picked up a replacement bellow - cost 33 NZD. Now that ain't bad. My task is to now cut the other one out (CAREFULLY), make up a jig to hold the pipes in the correct position/alignment and weld the thing in. This time I think I will do the weld. I will keep you posted with photo's.

Anyone out there tried the ceramic solution on these manifolds?

Cheers

Yes I went with new ceramics and did away with the heat shields. I reckon they are really good. Pipes cool down quite fast and gives more room for other access to bits in the engine bay .Got mine from a mob in Sydney

Hi Peter - who in Sydney? Did they supply a new manifold ceramic coated or use your old one?

I have had a closer look at mine and I think I am going to have troubles removing the after market bellows and then being able to tig around the back between the pipes. I don't know that they will have left me enough meat to use. I may have to fabricate some joiners. YUK. I am keen to give it a go but I need the 4 wheels back on the road and bringing a new set across the Tasman may be a faster option right now. I can then play with the old manifold at my leisure.