Oil turning black after 800 km. on 2000 in-line 6 Jeep Charokee

oil sender failing circuit problem -- sludge-- filter failure ---pump failure

check oil pressure
using a real gauge at the engine block sender hole.
do so cranking not started.
0 PSI?
the sender (icon magic) goes on at below 3-5PSI
and 5psi is doom levels.

did you use correct oil weight could be sending unit. high miles?

it's either leaking oil or burning oil.

replaced the oil and re set computer to fresh oil change
thes older models will only go aproxamitly 5000k on oil change
it may not have been reset at last oil change
key on run motor off depressed gas pedal to floor 3 times within 5 seconds of key on run
then start motor to re set oil life system

the oil that came out of the sending unit may had got into the starter causing it to burn out and now has a dead short in it

the 1st thing u do is have the oil pressure tested with a test mechanical gauge by a shop, most times it is just the oil pressure sending unit is defective, but never assume that is the problem, low oil pressure will distroy a $5000.00 engine very quickly, u can just try a new sending unit, but highly recommend a pressure test with a mechanical gauge before you run the engine anymore.

Check your spark plug, wires, distributor cap and finger. If you spark plugs older than 15000ml, replace them. To check your spark plug wires, use a tester (U can buy at any auto store) you hold direct on the wire and a small sparkling will show you if the wire works or not. You can check the wires also with this: use a single spark plug (don't remove one out your engine!), remove the wire from first SP, connect it with the single SP, hold it to ground, let someone start your engine...you need to see regular sparks.. do this step by step with all 6 wires. If all wires are fine, check the SP's, If you miss on one wire, replace the wire, if you miss on more than one, chekc the distributor cap and finger. If this items are older than 20000ml or 5 years, replace them.

City driving is about the hardest thing you can do to engine oil. If your primary driving is city driving it would be advisible to cut the oil change duration by a third to help keep it clean.

It could be worn camshaft bearings that is lowering your oil pressure. I had the same situation with my 2000 Jeep Cherokee 6 cyl. Changing the oil pressure sending unit did not make a difference. I used a higher viscosity oil and that prolonged the life for almost another year. If you put an oil pressure gauge on it and let it run at a prolonged normal temperature, it will give you a definite answer wheter or not the engine has low oil pressure. The real problem is finding the cause. Camshaft bearings are a likely source. According to the spec book, the I-6 engine had low oil pressure numbers to begin with.