Hey Everyone,

I'm in the middle of a Disco 2 build and I'm trying to troubleshoot a low oil pressure issue. To summarize I bought a 2002 Disco for cheap, drove it maybe 200 miles of highway driving home without issue. Next day I try to drive it in the city and it immediately overheats; still no check oil or engine light. I take it apart and the heads are a mess, but the rest of the engine internals look good. I do some part replacement, fire it up, and it sounds great. Oil light flickers on and off at hot and cold idle which is new, so I just put a cheap Harbor Freight gauge on it, here are the reading I got:

Initial startup: 32 PSI
Initial Cold Idle (1k RPM): 8 PSI
Steady Cold Idle (750 RPM) 6 PSI
2K RPM Cold: 16 PSI
Steady Hot Idle (700 RPM) 7 PSI
2K RPM Hot: 14 PSI

Engine has 82k on it, and is now running Shell Rotella 15w40 T4 with a Fram Filter. Vehicle hasn't left the driveway yet, put plan was to run crap filter and this oil for 50 miles or so, and then run Rotella 15w40 T6 and a better filter.

Brief Summary of the work I've done is:
Head Gasket Replacement w/ New Bolts
Heads Machined & Tested
New Complete Rocker Assemblies
New Lifters
New Push Rods
New Water Pump
New Plugs & Wires
New Oil Pump (Old Pump Looked Fine)
New Timing Gear & Chain
New Main Seal
New Plugs & Wires
New 180 Thermostat
Cleaned Timing Cover
Cleaned Oil Passages in Block (Very Clean)
Cleaned Oil Pickup (Not clogged) w/ New O-Ring
Cleaned Oil Pan (Some Sludge at Bottom)
Misc Gaskets Replaced During Head Job

The thread can be found here: https://landroverforums.com/forum/bu...ild-nh-101158/

But to generalize I started with this:




And brought it to this:



Anyone have suggestions? What are the minimum PSI requirement I should be looking with a Disco of this age and miles? Appreciate the help.

Oh; and it doesn't overheat now.

 

According to the RAVE the minimum is 10 psi at hot idle (although the light comes on at 8psi, if memory serves) and when hot at 2000 RPM it should be 50 psi. The relief valve opens at 50 so you shouldn't ever see it higher than that.

 

Well you could try a new oil pressure switch, but those readings are pretty low and 7/8psi is when the oil light comes on. I would say you either have a walked cam bearing or worn main bearings.

When the light flickers does the engine sound any different?

 

No, the engine sounds just fine. Any idea how I can check to see if I walked a cam bearing? I'm pretty sure I'm up to dropping the oil pan to check the main bearings myself. Thanks for the response.

 

Jesus, I'm nowhere near that.

 

The Rotella T4 will by fine, T6 is to thin unless you plan on some arctic duty. Some use it for a winter oil in those climates.

 

Yes, you can drop the pan to look for a walked cam bearing, pretty easy to see. If you have better pics of the cam from when you had the heads off we can look at those. If it is not a walked cam bearing then it is likely a broken oil pump gear.

 

T6 used to only be available in 5w-40, now also available as a T6 15w-40, always an option too.

 

I just dropped the pan and pulled the timing cover off. The oil pump gear is not broken, and the oil pickup tube has a good o-ring seal. I’ll take some pictures of what I can see tomorrow as far as cam bearings. Not too sure what I’m looking for though. Thanks for the help all.

 

I’m going to pull the main bearing a tomorrow morning and have a look. Should I pull only the main bearings, or should I pull the rod bearings as well? Do rod Bearings contribute to oil pressure, I don’t see an oil passage on the diagrams; how do rod bearing get oil? Thanks!