A shop is a fantastic idea, just be sure that they are willing to install the rod bearing in situ...with the motor still in your Disco via the oil pan removed underneath...if you want to avoid paying for having your motor pulled out of your Disco for the job.

A full engine rebuild would include new head gaskets, machining heads, new crank bearings, new cam bearing, **AND** new rod bearings.

That's great if you want to pay full price for full service.

On the other hand, if you just want to solve rod knock by replacing your rod bearings, then that can be done on the cheap.

Your shop will need a new oil pan gasket ($10) and new rod bearings from eBay ($38).

Plus, since they have to drain the oil to remove the oil pan, they will need 6 to 6.9 quarts of your preferred oil (e.g. 15W40 Rotella).

To be clear, just replacing rod bearings is obviously *not* a full engine rebuild. If you want a "new" motor then do the full rebuild.



But if you just want to spend as little as possible solving only rod knock, then have them change the rod bearings only. Don't pull the motor. Don't open up the top of the motor. Just drain oil, drop pan, remove rod caps, replace rod bearings, reinstall rod caps, install new sump gasket, reinstall oil pan (sump pan), refill with oil, done.

 

I'd double check for exhaust leaks, I can't count how many times knocks have turned out to be an exhaust leak

 

After watching the video and heard the sound, I'm sure that is a lifter. When the video started the engine was warmed up already on the gauge. I am familiar with that sound and had it for over 3 years. It get really annoying especially on drive thru. Very faint when your window is up. Youll hear it sometimes on intersection stops. You hardly hear it pass 1500-2000 rpm. Youll be lucky if you try any filter or oil combinations and make the noise disappear. If my observations were wrong, change the bearings and you might have the same sound after.
If it was an exhaust leak, roll down your window and upon acceleration drive near beside a highway wall divider at an average of 1500-2000rpm, you will hear more of the exhaust leak than the tick.

 

If you have an exhaust leak you will sometimes be able to see black streaks on your exhaust manifold (or wherever) near a leak.


The way to differentiate lifter knock from rod bearing knock is that lifter knock is higher pitched and loudest at idle, whereas a rod knock is lower in pitch and is the loudest if you rev the engine fast (but not too high because you are dealing with a damaged motor!) and then quickly let completely off the gas pedal.

That will get the most centrifugal outward force and the least inward force from the cylinder combustion. So as the engine slows down RPMs you will hear a loud thunk, thunk, thunk ... sound IF it is from a bad rod bearing.

 

Thanks guys! We have a mechanic friend coming over tomorrow to see if he can diagnose it. Not driving it until then. Fingers crossed it’s nothing too serious!

 

Just in case anyone is curious...My husband decided to drive it this morning to see what it's doing before his friend comes and I took two videos of the sound when we got home (wasn't as hard as I thought! should have just shared a video in the first place). It's not as loud and metallic as it was the other day, but you can definitely hear it. I think it does sound slightly different than the video that I shared off of youtube. The first video is with it in neutral, the second video it's in park, though I don't hear a difference between them. It wasn't idling rough at stop signs like it was for me again today, so not sure if it's a pressure build up doing that since both the trips where it was acting better were shorter. His mechanic friend is really good, but since he doesn't work on Land Rovers and I know they are quirky I thought I'd share here too.

 

I have not much to say but they are the same. I hope I'm mistaken. But 'm sure its a lifter noise.

 

That's much quiter. That sounds more like valvetrain noise as a result of a cracked oil pump.
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I'd put money on it
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