I just bought a 2001 Land Rover Discovery II with 120k on it and changed the oil and filter almost immediately, using Royal Purple 10-40.

I notice that when I first start it in the morning, it sounds a little bit like a diesel and clatters. Once I accelerate and drive it for a couple of minutes the noise goes away considerably. Once it's very warm, it can hardly be detected at all, sometimes not evident even if I put it under a load. It's a little different noise than the sort of valve clatter from using lower octane fuel. It also does not run rough or demonstrate a loss of power when the clatter is most prominent, it's just very noticable and again, sounds very much like a diesel engine for the first minute or so.

I'm wondering whether this has anything to do with the sticking exhaust valve problem that the LRs are famous for and if not, what could be causing this noise under these conditions? Could it have anything to do with using the Royal Purple synthetic oil? How do I fix the problem?

thanks

 

What filter are you using?

 

It's a NAPA filter. I think the salesman said it was made by Wix for NAPA.

thanks

 

I also wanted to ad that if you start it up and do not accelerate, the clatter does not occur. It's idles very quietly. Once you accelerate, it clatters and when I come to the first traffic light about 1/2 mile away, it's gone. If I hold the brake and step on the gas to load the engine, it can be heard faintly. Once it's entirely warm by the time I arrive to work, it can't be heard at all.

thanks

 

Open the hood and listen from there, get a better general idea where the noise is coming from

 

 

I used a long screwdriver and placed it against various sections of the engine while running and placed my ear directly to the handle to increase the focus of the noise. It seems to be loudest at the level of the engine heads rather than the valve cover gaskets, which made me think it had something to do with the valves themselves. It does not sound like the slower and more rhythmic sound a rod might make, but rather a more busy type of chatter that would represent multiple moving parts being affected simultaneously, such as the valve lifters or something.

What puzzles me is that it stops under acceleration and goes away when the engine becomes warm. In fact, if I start the truck at any point during the day after it's been initially driven, the noise cannot be heard. It must sit overnight. I get no indicator that the oil pressure might be failing and one would think if this were the case it would make this noise at an idle when first started, but it doesn't or that it would intermittently fail at highway speeds.

One thing that puzzles me is that the exhaust manifolds appear to have a great deal of rust and the housing of the engine appears to be rather oxidized more than I would have thought possible by comparison to the condition of the vehicle in general, making me think that it's possible that the engine is not the original and appears this way from being exposed to the elements while at a salvage shop, but I don't know how to check to determine if this is the case or not.

It's definitely an odd sort of problem.

 

PM me your tele number so I can call you.