oil light comes on when cold

When I leave in the morning the oil light is on unless I shut off the jeep, wait a couple seconds then crank it again, then it goes away. bad or going sensor?
thanks

Could be a sensor, could be low oil pressure

yea but it's only on my first start or if she's been sitting for a few hours..

I would check and replace the oil pressure sending unit, right above the oil filter, and change oil and filter while your at it as well just to be safe. Don't want to budketize your engine!

kb0nly said:

I would check and replace the oil pressure sending unit, right above the oil filter, and change oil and filter while your at it as well just to be safe. Don't want to budketize your engine!

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Dave

This is where it would be great to have an oil pressure gauge!
Probably it is the sending unit.
I had mine do it once or twice before I switched to synthetic when it was sub zero. I think the dino had thickened to molasses in -14c. Once it warmed slightly and I stepped on the gas the light went out. Used a block heater next morning, no light, so I knew it was the oil and or filter.

Sorry i couldnt resist that term... Budke should get a quarter each time we use it as a royalty..

BjBnet said:

yea but it's only on my first start or if she's been sitting for a few hours..

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Ed Zachary - the oil is cold and not flowing well. Maybe my logic is wrong.

I am thinking the oil could be pretty thick and tripping the light. The light probably has a safety margin built in so it stays lit for a little while after the oil pressure is good - the PCM/BCM probably has a "memory". The reason it clears if you shut it off for a few seconds and restart it is that the oil has warmed enough to not trip it any longer, and shutting it down clears it from "memory".

Just out of curiosity, what weight oil are you using?

The oil pressure sender is a simple circuit. There is no memory in the PCM or BCM that resets or anything like that.

Basically, the sender is a switch. Oil pressure closes the switch and completes the circuit. Lack of oil pressure keeps the switch open, the PCM sees 5 volts(open circuit), and sends a message to the BCM or cluster(I can't remember which) to illuminate the oil light.

Most commonly, the oil sender starts to wear out. It's a simple repair.

Be careful with that bud. No oil getting to an engine is as you know very bad.

I just did an oil change. After I started it back up again the engine didn't sound to good and vibrated really bad for about 2 seconds because it was starved for oil. If it were to do that for a couple minutes. Yikes!!!

You don't want your engine to go without oil for too long. Def get in touch with Jeep Technicians.

I use 5w30 Castrol Full Synthetic. Have been for a few years. This just started 2 weeks ago so it's not the cold because it's been above 0 here for over a month.
I'll replace the sensor see what happens
Thanks again guys

I thought some of you guys could use this. HOW-TO oil pressure switch

http://www.ehow.com/how_5876296_replace-pressure-switch-jeep-liberty.html

loves_off_roading said:

Be careful with that bud. No oil getting to an engine is as you know very bad.

I just did an oil change. After I started it back up again the engine didn't sound to good and vibrated really bad for about 2 seconds because it was starved for oil. If it were to do that for a couple minutes. Yikes!!!

You don't want your engine to go without oil for too long. Def get in touch with Jeep Technicians.

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you might want to put a little oil in your new oil filter before you put it on. I put about a quarter of a quart in when I do mine. That's about all that will fit before it will spill when you go to put it on. The vehicles with the filter vertical are the easiest. I've changed them before and always fill the filter with oil and never get the death knock.

BjBnet said:

I thought some of you guys could use this. HOW-TO oil pressure switch

http://www.ehow.com/how_5876296_replace-pressure-switch-jeep-liberty.html

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The way they say to do it ain't worth a darn though... You don't need to remove anything except the oil filter to get to it. You can actually access it from the top, if you drain the oil and remove the filter then you can reach up from underneath or down from the top and replace the sending unit.

BjBnet said:

When I leave in the morning the oil light is on unless I shut off the jeep, wait a couple seconds then crank it again, then it goes away. bad or going sensor?
thanks

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I've had the same problem. When I cranked up my KJ in the morning the oil light came on (running full synth 5W30). I immediately shut it down. Waited a moment and restarted, the light was off. I replaced the sensor and all is well. It only started doing it to me after I power washed the underside of my KJ while trying to isolate a PS leak. Don't know if it's related at all.

I'd love to stick a mechanical Oil Pressure gauge in the dash, or even just under the hood for peace of mind. Anybody make gauge pods for the A-pillar or a pod that mounts on the dash?

I had this EXACT same problem on my jeep... the easiest way to replace the sending unit is to remove the fan shroud housing (two screws at the top and it just lifts up and out)... I used a 1.25in deep well socket with a 6in extension... accessed it from the top... I don't think there is ANY easier way to do it...

wow great info guys. Glad to see I'm not the only one. Called an autoparts place this morning and they want $53 for the sensor...called the dealer for the heck of it.....$23!!
Thanks everyone!!

ptsb5a said:

I'd love to stick a mechanical Oil Pressure gauge in the dash, or even just under the hood for peace of mind. Anybody make gauge pods for the A-pillar or a pod that mounts on the dash?

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Same here, if anyone has any recommendations I'd love to hear them. Apparently some KJs have a gauge....auto parts place asked me if I had one or not because his listing was asking....??

No KJs have an oil pressure gage.

ThunderbirdJunkie said:

No KJs have an oil pressure gage.

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That is prehaps my biggest beef with the Jeep. No oil battery gage.