craziness with the exhaust leak

[ealex]

Ok. So its been a week that I've been fighting this exhaust leak. The local exhaust shop pointed to #4 cylinder exhaust gasket (block to manifold). So I bought 2 of them and the manifold to pipe gasket. They are installed, torqued to the Rave CD specs. Leak is still there. So I start the engine this morning and put my hand under the manifold and try to feel for the leak...I feel it coming from what feels like between the block and the head. Due to the heat, I can't really keep my hand there long enough, but with welder's gloves I clearly slide past the exhaust manifold before I feel the puffs hitting the glove. It is below the gaskets and further inward on the block. Thinking it might be a head gasket, I do a compression test on the #2 and #4 cylinder. #2 is at 160 PSI and #4 is at ~145 +/-1. The gauge does not go down when I stop cranking the engine.

Its a 2000 D2 V8 w/80K miles.

Questions for you all:

1. Can a head gasket on the rover 8 leak only exhaust? My oil and coolant are perfectly clean - no milkshake.
2. Can a leaky head gasket only leak under running pressure? There was no sound of it leaking under the 145 PSI...but I know combustion pressures reach much higher.
3. Can you think of any other way to narrow down what it could be? Tomorrow I will pull the exhaust manifold and de-grease the area and see what can be seen...but under that cylinder there is a lot of oil and carbon build up, while the rest of the block is relatively clean.
4. What can it be at worst? Cracked head or block? Has anyone even heard of such shit?

On a lighter topic, who the fuck put the SAI pipes behind the intake manifold and above the spark plug wires?!!

What's the Land Rover part number for the monkey that can replace the spark plug wires LRT-MON1234?

[6cuda6]

What i would do is a LEAK DOWN TEST..at least then you can put pressure in the cylinder and see if it leaks between the 2....

So you can check the block to head using it normaly...then rotate the engine to open the exhaust valve, plug the exhaust with a couple rages to pressurise the exhaust system and you can see if it leak out between the manifold....

If it was a headgasket you would more than likely have other issues..coolant loss etc.....

[ealex]

Hmm. Thinking back, there might be some coolant loss. Although I just did the flush 2 days ago, so I guess it could still be settling down...it was about 1/4" low this morning after getting up to running temp last night. I've topped it off twice, both times the coolant tank was 1/4" low...so who knows if its because of the flush or the head gasket leaking...

[Rovin4life]

exhaust manifold is probably cracked or the crack is just south of the flange.

seen it a few times


use a smoke machine or plug up the rear and see where its coming out from .

[Rondo]

Ditto on the manifold being cracked. It is a common problem on discoveries. If you provide some backpressure on the exhaust it will aid in pinpointing the leak.