Well having repaired the jacking point, floor and other parts I was looking forward to driving my car during the short Swedish summer...but no

I was driving along merrily when suddenly I hear a noise that made me think of bad exhaust header, there was also a slight loss of power. Back at the garage I got under the car and removed the tins under 3/4 thats where the noise was coming from, no sign of exhaust header leakage. The noise is really bad, the only other thing i can think of is head gasket but I cant see anything.

The engine a 2.0 CG was rebuilt last year (by me) and I did use head gaskets, the engine has done< 1000 km since the rebuild

If members have any ideas about how to go about diagnosing this problem then please let me know, thanks

Check the spark plugs for one that came out.
Also check the air injection ports, although a missing plug in an air injection port shouldn't affect running - just make bad noise.

Bad head gasket makes a whistling or a mouse on steroids "squeak-squeak" noise.
Shit load of noise is a blown out sparkplug.
Valve adjuster way out of whack, real tight or way loose is a dropped or sunken seat.

Sparkplugs are ok, the air injection ports were plunged with NPT plugs. If one of these has worked its way loose it'll mean dropping the engine but they were screwed in pretty hard




There is a shit load of noise, no mouse on steroids.
I guess a leak down or compression test is in order?

NPT plugs? those are metric threads.

You can't stick a probe in to see if they are still there?

I think the original pipe had a tapered pipe thread.
I will poke around in the holes and see if they are there
Thanks

Before you go through the trouble of a compression and/or leakdown test, I would go ahead and pull the valve cover off. If it's making that much noise, you'll probably have some visual evidence of the problem in the valvetrain.

But of course, if you find a missing or loose spark plug, then you'll already know what the problem is.

Did you weld up the head tins?
The injection ports should be visible....unless they are covered now....

Have you checked the intake manifold gaskets for a vacuum leak?

I had an intake gasket fail on me earlier this year while driving. Made the most god awful noise along with a significant loss of power.

Problem solved! I would like to give a big thank you to everyone who helped. Chris hit the nail on the head when he suggested taking a look at the air injection ports, I don't think I would have thought of that myself. One of the plugs had come loose. I didn't have a metric Allen key so I just pushed it in, now shes purring like a kitten.

Surprising that so much noise can come from such a small hole...no joke intended

I take it you don't have kids...

Nice

I used 3/8" NPT pipe caps to plug the air injection tubes. One came off in the middle of the mile long tunnel going into Zion Nat'l Park. It sounded like a war zone. Slightly less loud than 3 kids Mike.