Thread: Sudden oil pressure loss 2004 V8

what happens when it cools.oil grade to light?

Hi, IMO you should rule out the oil pressure switch first.... screw in a pressure gauge instead of the switch to see if it's low pressure in reality or a switch missbehaviour... if you unplug the switch the warning should go out, if it doesnt the problem is electrical(short to earth on the circuit)

Originally Posted by sierrafery

Hi, IMO you should rule out the oil pressure switch first.... screw in a pressure gauge instead of the switch to see if it's low pressure in reality or a switch missbehaviour... if you unplug the switch the warning should go out, if it doesnt the problem is electrical(short to earth on the circuit)

The rattling noises I am getting would suggest that oil pressure is low to nonexistent anyway. I do have a pressure gauge somewhere but I think would only show low or nonexistent pressure. I don't want to run engine any more than necessary until I find problem.

G`day ,

did it rattle when you first started it from cold , did it stop rattle or continue to , what time frame ?

Is the oil light the only obvious thing .

If not a rattler i`d do as suggested and rule out the sensor .

This actually happened to mine, just no rattle. oil light really slow to go out, maybe 5K after an oil change, {lots of horrible pics around of broken oil pumps, } checked sensor and change of oil and all's been fine since---

what oil was put in?

Hi There,
If you don't want to run the engine, take all the spark plugs out to reduce the load on the engine, (also won't start) then take the oil pressure sensor out and crank the engine over. Put a bucket under the engine, Oil should flow freely out of the sensor hole, if not suspect oil pump or oil pump drive.

I'm going to assume that you have checked the oil level and something unfortunate like the sump plug wasn't tightened up and all the oil has drained out hasn't happened.....(sorry just re-read your initial post, "oil level normal").

Cheers Marty

Ok, sump is now off, bits of metal at the front end. Looking up at front end of crank can see more metal from oil pump housing. Seems oil pump has destroyed itself. Now to remove timing cover and see just what is what.

Ok, now timing cover is off, can say relief valve and spring is ok, but not much else is Appears that the outer ring was fractured, part of it went outwards and jammed in the void and all came to a stop, but crankshaft keeps turning and the drive sleeve disintegrate.
You might be able to see from the pics that the key in the crank is damaged as well as timing cover and retaining plate.
Now need to decide to fix or replace
As I said originally, maybe good opportunity to go to tophatted 4.6.
Haven't yet pulled a big end to see if any damage, this will be decider I guess.