I'd think that worst case you'll have to drop the HE and have a shop tack weld it back in place if that's what ends up being the problem.

Ok - so that was not the problem! The exhaust putty worked a treat and the exchanger is rock solid. will have to check for exhaust leaks from the whole system before taking things apart. Wondered if the cat had packed up?

Outstanding.

If cat clogged, you will feel it in poor acceleration or glowing red hot temps on the cat.

Look around for any carbon buildup on the exhaust joints and at the manifold gaskets. Like Draco said, if the cat was gummed up, you'd notice performance issues as well as a glowing hot cat. Good luck and keep us posted!

Will do - thanks for your support and advice......

Ok - so not an exhaust issue so have created a video of the sound when engine running. As you can hear, when increasing revs steadily no noise, give the accelerator peddle a pump and you can hear a noise - any ideas? Do you think it is a valve issue, ignition issue or (dreading this) a bearing issue?

https://youtu.be/QlETDee7s8c

Link to video doesn't appear to be working.

+1 Link broken, make sure it is in public to view

Sorry folks - link should now be working....ticked the wrong box!

Remove the lower valve covers and have a look at the head studs.

Uh oh,

Sounds like a head to case leak, maybe cam tower.

+1, remove covers and inspect studs or if you can do a leak down test. That will certain show a leak and pin point were it may be coming from.

Sorry to see your troubles Brother :-(

Thanks for the suggestions. Friend of mine suggested chain tensioner may have collapsed. What do you think?

Looks like a lot to investigate!

That is possible since you have the SC, if you do not know the complete history, you will not know if PO put a tensioner guard or updated them to a carrera oil fed ( you would see oil line going into the chain covers )

You can remove the covers and inspect the tensioners to make sure.

Hi everyone - just thought I would update on the issue. After a leak test two cylinders were well down so engine had to come out - no loose bits and pieces anywhere, studs all good etc. Problem has been identified as blown head gaskets - the springs inside two had gone bad and two others were in the process of failing. So - new gaskets purchased and ready to go in - just a question - is there a 'right way' for the gasket to go? One side appears flat and the other side slightly curved.

I don't recall. You might consider sending a PM to Bruce (flat6pac) or John Walker both would probably know for certain.

Thanks Cabmando - can't find flatpac6/John Walker PM as the area had been disabled by administrator! Can you provide a link for me?

Post a pic of your old gasket and new one.

Here is a picture of the one that blew -http://forums.pelicanparts.com/uploa...1538245894.jpg

Ooops - last post is a new one, this is one that blewhttp://forums.pelicanparts.com/uploa...1538246161.jpg

On a new one there is a 'flat' side which does not show up very well.