Hi

My 2004 Series 2 Discovery with 4.6 litre V8 has suddenly started making a noise not too distant from a steam locomotive.

It's still running OK (apart from the noise) with no obvious misfiring and the water temperature is normal.

I'm at work and a brief look under the hood seems to imply the noise is on the right side of the engine (looking forward from the rear of the car) and, putting my hand as close as I dare, I could not feel hot gas escaping from the joint with the manifold to the catalytic converter pipe section.

Might it be a manifold to head issue? I won't be able to look at it properly until the weekend...

Thanks for any help

Geoff

 

Could be
Use a rag or something to partially block tailpipe, this will amplify the issue and make it easier to locate

 

Or use the output of shop vac , pushing backwards through a non running system, if you want a less blistering test.

 

Whatever it is, do not continue to drive it cause you could be costing yourself more money in expenses.
Do you have a check engine light on, if so what is the fault code numbers.
There iw a good chance that if the noise is coming from the side of th nine, near the exhaust manifolds it could be a cracked or broken manifold or bolts or worse yet a blown exhaust manifold leaking exhaust which if not felt with yesterday, can burn your heads or block surface.

 

When my headgasket blew between the cylinder and just behind the exhaust manifold, it sounded like a steam locomotive.

If left unattended for too long, you run the very real risk of hot combustion gases etching a trench in your head or block as they escape.

 

Block the exhaust as dusty suggested and listen to where the back preasure is coming from

 

I agree with the rest of the info so far. Don't run it anymore than you have to. An exhaust manifold and/or gaskets or even a head gasket, is WAY cheaper than replacing a head or the entire engine if it is burning a trench into the deck or the head.
Another possibility that I have seen only one time (and is not as likely, but possible) is if someone tried to replace the O2 sensors and FAILED. I had a car come into the shop once that had stripped threads in the exhaust where the O2 sensor threaded in. It made it a while until it finally fell out. That car sounded like a locomotive also!

 

SAI pipe or hose loose?

 

Hi

I was somewhat trapped yesterday as the noise started as I drove to work and I had a 20+ mile drive back home.

I've taken the car off the road and will look at it this weekend and will report what I find.

Based on the noise I was hearing as I drove home I'm inclined to think it may be the joint of manifold to front pipe. I have ordered gaskets and nuts/screws for both the manifold gaskets and the gasket for the joint I think it may be. Hopefully this will be enough and I will be able to sort it this weekend.

If it's a head leak, that's another issue altogether, timewise.... hoping that it isn't that!

Geoff

 

The 03 that I just took apart (for parts) had an inner head gasket problem and sounded exactly as you describe. Look for oil in the valley gasket area.