Hi all,

My Disco has had a tick for a while and just made a short video of it in hopes someone could recognize the sound. Lifter noise? Exhaust leak? Liner? This was a cold start after not running for about a week so the oil was quite settled if that makes a difference.

 

To me, it sounds as thought you have more than one issue. Most likely you have the infamous land rover tick due to a worn lifter or cam lobe, cracked oil pump gears, or "walked" cam bearing. In addition, it sounds as though you have an exhaust leak.


To diagnose, I would do the two following tests, You can Google or you-tube either of these methods for further clarification.


For the exhaust leak. Do a visual first to look for missing exhaust manifold bolts, cracked manifolds, or a poor fit of the exhaust pipe to the manifold or even a loose spark plug.
If nothing stands out, find a old piece of garden hose about 2-3ft long. Firmly hold one end up to your ear canal. (left or right side, doesn't matter, just pick the dominant one) Place the other around each exhaust port and the secondary air tubes. When you find the leak, you will hear it. repair accordingly from there.

For the Land Rover "tick". you can use a mechanics stethoscope or a really long screw driver to help isolate the location.
Using the same method as with the hose, put the handle up to your ear, and the tip of the tool on the valve cover above each spark plug.
When the tick becomes loudest, you are in the ball park of where the noise is. Again, you'll know when you hear it.
You can also do this with the oil pump from underneath and possibly check for a cracked flex plate at the Transmission Bell Housing.

BE CAREFUL!!! You are positioning the screw driver in near moving parts and you must turn your head 90 degrees from the tool to listen. You don't want it to slip into the moving parts.


Post up what you find.

 

Deal with the exhaust leak first. If you have a strong shopvac, inset the tip at the exhaust and tape it up. Fire it and see if there are leaks near the exhaust manifold or the pipe connecting to the Y going to the cats.

 

Thanks all for the input. I saw the shop vac trick on another thread, I'll give that a shot first to find the exhaust leak. I have no doubt I have one.

 

That worked really well. Found a big leak on the passenger side where the cat pipe goes into the exhaust manifold. There's also a small leak on the front edge if the muffler. I might try to jb weld the one on the muffler shut and get a new gasket for the big leak.

 

Your engine generally sounds like a 'bag of nails' but IMO that 'ticking' is a slipped liner, but I hope not.

 

Fixed the exhaust leak. A new gasket for the passenger side cat pipe/exhaust manifold union and a dab of JB weld for the small leak from muffler sealed it up. Engine bay is much quieter, especially when sitting inside the truck. It still has a little rattle - I listened to a few videos of a (alleged) slipped liner and it doesn't sound like that metallic tap. The noise sounds like it's lower on the engine, kind of towards the front? Oil pump? I'll do some more snooping and report back. I've done some reading on the oil pump gear replacement. What are the symptoms of a cracked gear? Thanks all for the input so far!

OffroadFrance - thanks, I agree this truck as a whole sounds like a "bag of nails" when driving it! But I just like to blindly think it's just my bucket of tools jumping around when I hit bumps.