Worried About Oil Pressure

RBBailey

RBBailey

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Callsign: KF7KFZ
I'm so close to being on the road, I really don't want another project before I can actually start driving it. Especially since the Range Rover with 311k on the clock is starting to break down...

The 300Tdi seems OK as the PSI rises to 43-45 just a few seconds after start. It stays at 40-45 while cool, idling or revving.

However, I've managed to get the truck up to full operating temps twice now, and the PSI drops to 18 when at idle.

Oil level is normal. I don't know what type/weight is in it right now. Was planning on changing the filter after a few hundred miles.

Should I be concerned? What should I do to confirm if there is a problem? The pressure sender and gauge are both new.
 
Jeff B

Jeff B

Well-known member
I think I read that 20psi is normal at idle??

If you're seeing 18, I dont think I'd get alarmed.....yet.



.
 
javelinadave

javelinadave

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Staff member
From what I remember reading the light goes out at 6-9 psi and 15-20 psi is normal for an at temperature 200 or 300Tdi engine.
 
Uncle Douglas

Uncle Douglas

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What rpm are you idling @? Pump rpm has a good bit to do with oil pressure. 18 psi is fine when warm @ idle.
 
RBBailey

RBBailey

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OK, I'll not panic.

I'm at about 750-800 RPM. I set the tach by using an app on the iPhone... so....... ;)

I'm taking it out again this afternoon, and I'll record specific data as much as I can.
 
AdamSanta85

AdamSanta85

Well-known member
RBBailey said:
I'm at about 750-800 RPM. I set the tach by using an app on the iPhone... so....... ;)
Click to expand...

Oh do tell. I recently just set my tach. "Eh its supposed to be 800, ill set it to 800". Do you have to put something reflective on the crank pulley or something?

Your oil pressure sounds fine. General rule of thumb is 10psi per 1000 rpm off idle. (yes very simple old rule but generally holds)
 
RBBailey

RBBailey

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Callsign: KF7KFZ
I put a stripe of white paint on the pulley. The app is called Strobe Light Tachometer. It seemed to work well, as when I had the lights in the garage turned down a bit, I was able to clearly see the mark progress back and forth, then settle as I dialed the strobe speed up and down on the phone.

The VDO Tach isn't exactly precise as far as showing an exact number on the face. So I figured being 20-50 RPM off one way or another wasn't going to matter much. But I may recheck it before I finalize the dash install.
 
RBBailey

RBBailey

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Callsign: KF7KFZ
Roverman2010 said:
You don't need no fancy apps to check your rpm, been using a strobe light for years on diesels.
Click to expand...

LOL! The voice in my head said something like, "You don't need no fancy strobe gun to set the timing, shouldn't there be an app for that?"
 
Roverman2010

Roverman2010

Well-known member
aeo said:
What's the range for oil temp?

Thanks,
Alex
Click to expand...

90 -100 deg C, time to shut down and cool at 110 C

One of the biggest killers of engines is cold oil, the use of oil coolers without a themostat is the reason. The marketing guys say how cool it is to have oil coolers on this and that, but if it's not controlled it's of no use. That just my thinking.

Engines run better at optimal oil temps, some say even hotter? Check out the oil company web site for the oil you use. And if you don't tow or haul large loads in the dead of death valley going up mega moutains, ditch the cooler or put a theromstat in line.

This is just my thinking. And having been in charge of oil testing in one of my former jobs. Sorry my temps are in C but that's my condition.
 
RBBailey

RBBailey

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Callsign: KF7KFZ
UPDATE:

With this warm weather, I've been running at 185-190 water temps once fully warmed.

Even on the freeway, I'm only seeing 20-22 psi oil pressure. About 16 psi when idling at 900. (Which is my real idle speed as far as I can tell.)
 
RBBailey

RBBailey

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What other tests should I do before cancelling my subscription.... er.... before buying the bearing sets?
 
jymmiejamz

jymmiejamz

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If the motor isn't knocking and the light isn't on, I wouldn't be too worried about it.
 
RBBailey

RBBailey

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Callsign: KF7KFZ
Fact is, I think there is a knock. I tried to ignore it, but yesterday I remember I was ducking down under and in the cab trying to determine if I was hearing things or not. I brushed it aside because the engine is so loud that I really could not tell.

  1. OK, so I need to do a manual pressure check.
  2. I suppose I could pull the pan and visually check one or two of the bearings, but I'm going on what I know of checking the 2.25 Series engine last year.... when this same thing happened.... twice... right after a two year project to get the truck on the road....
  3. I could try the pressure spring/valve, but from what I understand these symptoms don't really match.
  4. I could try simply replacing the oil pump.
What else?
 
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