Hi,firstly a big thankyou to members of this site,been very helpful with problems sorting out my Disco 2 .

A few weeks ago I purchased a Discovery 2001 with a known overheating issue,after pressure tests etc it came down to new head gaskets.
I stripped the motor down,(the RAVE manual is great) sent the heads off to the machine shop,a few days later got them back all sorted,both were bad,the drivers side the worse.
Anyway put it all back together,followed the manual to the letter, new gaskets and bolts etc,filled the radiator,bled the system,started her up and all is perfect.
Did a trip of 200 miles and ran fantastic.
Few days later the Disco started to run hot,heard the electric fan cut in after a few miles drive to the shops.
I had renewed the thermostat so decided to check it out in a hot pan on the stove,found it was opening at around 200f,got another and installed it,refilled the cooling system,bled it,and started it up to check temps with a digital temp gun on the hoses and radiator,( I have ordred a ultra gauge should be here in the next few days) anyway as soon as I started the Disco up the oil light came on,it was not on before,thought perhaps I had splashed water on one of the plugs under the filler tank/cap whislt lifting to bleed the system causing a short,sprayed the plugs and oil pressure switch with WD40 to try and dispel any water,still got the light on.
I did a oil change and filter after the headgaskets,old oil seemed fine and not sludgy.
New oil was 10/30 Castrol semi,oil filter a fram.
So is this one of those strange Landrover electric whimms,a faulty sensor,or what!!
Going to try a borrow a oil pressure gauge and check pressure tommorow.
Seems strange,engine running and light off,turn engine off to change thermostat, refill cooling system and bleed,restart engine and oil light on.
So now with the oil light on I can not run the engine to see if the overheating problem is any better.
Any thoughts much appreciated.

 

Take a look around the thermostat area for any electrical connections that might have come loose while you where in there?

 

Thanks will do,I am more inclined to a wire loose,or shortning from the water than oil pump/ dirty pick up etc.

 

If you have a grounded oil sender wire the light would stay on. OIL PSI test good idea. Fram oil filter not as good as many others you can buy. Might try a different filter. Don't run long with light on.

 

What are your ambient temps? 10w30 is really too thin for these trucks and can cause a low oil pressure light at warm temps, or when the engine is hot.

Somewhere in one of the RAVES it says 10w30 is only usable up to ~90 degrees F.

Also, did you follow the 'procedure' for changing the oil? You are supposed to drain and refill the oil, then swap the filter. I believe failing to do this can cause the oil pump to lose it's prime, though I've never heard of it actually happening.

 

Outside temp here is around 50f at the moment,and the engine was stone cold.
When I did the oil change I did not fill the engine first then swap the filter,and the pressure was fine,light off straight away,but thanks for the tip,will do that next oil change.
I am sure it's a grounded oil pressure switch wire,however finding out where might tale a while.
Pressure test first,then at least I will know which way to go.
Results to follow.

 

does the filter have oil in it?

 

Just checked oil filter,and full.
Also just did a earth test on oil switch wire and all ok, no grounding.
Only two things left,faulty sensor or low pressure.

 

Yes just unscrewed filter,loads of oil.
No grounding on wire,so only faulty switch or low pressure left.
Any bets which way this is heading.

 

time for a pressure gauge