Oil Pump Going Bad?

[bulax99]

Pretty sure my oil pump is about to take it in the shorts. Here's a brief list of symptoms:

- cold motor start is ok. Oil pressure pegs right to the 3pm position

- cold motor driving - ok

- warm motor idling - oil pressure drops to the tick mark between "L" and the normal 3 o'clock. Sometimes it will drop a smudge further.

- warm motor driving. Oil pressure is engine-speed dependent from (what I think is) low at idle to normal at anything over 1200 rpm.

So is the oil pump about to give up? I have to have the timing belt, and all the while-you-at-it's, soon and I'm hoping that the oil pump can be changed without much more labor?

 

[Julian Stead]

Mine does this, I would say it is normal, the oil gets thinner when hot, that is all that is happening. I haven't got my truck to 100% confirm, just it sounds familiar to mine.

 

[Spike555]

You need a different motor oil.
Shell Rotella T6 5w-40, change to it now. Problem solved.

 

[Julian Stead]

I use Mobil 1 0w-40 FS in both my toyota's, Toyota ask for 10w-40 in the uk, but most on here seem to use 5w-30. My point is I run 40 and my needle still fluctuates when hot, but maybe it is better than yours, can't really say.

 

[Trunk Monkey]

Have you always watched the oil press. gauge and this is new behavior or you just noticed the gauge and how it moves and when?

 

[bulax99]

I'll try the oil change. It's about time for one. The oil pump is an accessible part when the timing belt is done?

 

[Spike555]

I use Mobil 1 0w-40 FS in both my toyota's, Toyota ask for 10w-40 in the uk, but most on here seem to use 5w-30. My point is I run 40 and my needle still fluctuates when hot, but maybe it is better than yours, can't really say.

Here in the US 5w-30 is called for because of fuel economy standards, now most cars call for 5w-20 because of even stricter fuel economy standards.
I use 5w-40 in my truck and 5w-20 in my wifes van.

 

[abuck99]

Maybe the sensor is failing, I haven't noticed any mention of any oil pump failures in these 2UZFE engines here on the forum. I would remove the oil pressure sensor and put a mechanical tester on it and measure your oil pressure.

 

[Spike555]

Maybe the sensor is failing, I haven't noticed any mention of any oil pump failures in these 2UZFE engines here on the forum. I would remove the oil pressure sensor and put a mechanical tester on it and measure your oil pressure.

View attachment 1538680

That sounds like a lot of work when he's due for an oil change anyway.

 

[abuck99]

That sounds like a lot of work when he's due for an oil change anyway.

He'll be 4" away from the pressure sending unit when he goes to spin the oil filter off. While at the parts store for oil and filter, he can check out a loaner pressure tester at the same time. Doesn't seem like its all that much additional work.

 

[bulax99]

If it's a $30 part I may as well just change the sensor. There is so much tolerance dialed into the gauges and sensors now a days I'm either not used to a 20 year old truck or there's something wrong.

Nonetheless less I appreciate the advice guys (and gals).

 

[Julian Stead]

A oil change is more beneficial than a sensor. This is how you would expect your oil pressure to act. Look at the FSM above to confirm this, the difference between Idle and 3000 rpm, if it was steady I would be more worried,haha. Oil pressure will drop when the oil thins when hot, it still achieves the same if not better flow. Post a video and others can check there's, I know mine does it, but to what extent I can't remember.

 

[bulax99]

See pics. So does everyone else's LC do this?

 

[Jeepster09]

Most vehicles do not come with guages due to erratic readings....that is main reason they only have IDIOT light. I would bet on bad sender, like previously stated, take out sender and put in mechanical guage to see what pressure really is.

 

[Jeepster09]

The school of thought used to be you need 10 pounds of pressure for every 1000 rpm engine is running. So at idle they can read pretty low and still be ok.

 

[abuck99]

View attachment 1538740 View attachment 1538741 See pics. So does everyone else's LC do this?

That looks like it with in the same indication range as mine.

 

[bulax99]

Ok. That puts my mind at ease. I'll replace the sender at the next oil change while I'm down there.

 

[Spike555]

A oil change is more beneficial than a sensor? This is how you would expect your oil pressure to act. Look at the FSM above to confirm this, the difference between Idle and 3000 rpm, if it was steady I would be more worried,haha. Oil pressure will drop when the oil thins when hot, it still achieves the same if not better flow. Post a video and others can check there's, I know mine does it, but to what extent I can't remember.

If the sensor is not bad why sopend the money on one? Change the oil and see what5 happens, if no change then replace the sensor.
But if his oil pressure comes up, the gauge can still fluctuate, it's supposed to, but if his numbers are better then great.
He's due for a oil change anyway, so start there.

You guys all love to spend money you don't have to, I don't get it.

 

[Spike555]

Ok. That puts my mind at ease. I'll replace the sender at the next oil change while I'm down there.

But if you do that then you will not know if it was the sensor or the oil.
Do the oil change switching oils, see what happens. You just might save yourself $30.

 

[Trunk Monkey]

Again, if you've paid attention to the gauge in the past and this is new, then there's maybe something to chase. If you're just noticing the gauge and how it moves, I'd hold off on throwing money at things that might be normal.