Land Rover Repair: range rover 4.0 engine knock, engine additives, octane fuel

Question
Thank you for anwering my knocking question yesterday. I spoke to the seller this morning and he said his mechanic said it was varnish build-up on the rocker arms. Could I have an oil pump problem or plugged up oil ports? Thanks again, Chris

Answer
Hi Chris,

varnish buildup? Hmmm...

You can try running with engine additives to help clean up the varnish.  NAPA has a engine flush called SeaFoam that you can use BEFORE you drain and replace your oil.  Some owners have said that flushing with SeaFoam seems to solve the problem of TIC-TIC-TIC...

Don't forget to use the highest octane fuel available in your area. 91 or 94 (Sunoco has this).

You could also remove the oilpan and clean up under there with a solvent.  Do a through job.  A slightly plugged pickup valve has been known to cause engine tic.

IF all of this does not help, you'll have to consider replacing the rocker arms and lifters.  If you do this yourself, you can save big bucks.

I doubt it's your oil pump but perhaps an engine flush is your best start.  Proceed from there.  Oil pan removeal and a thorough cleaning (by hand) will be the next step.

Best of luck,

JohnMc

Have your oil replaced and use the highest Octane fuel you can find, 91 or 94.