Low oil pressure on startup

[brundige]

I just purchased a 2000(built in 99) bluebid TC2000 with a 24valve cummins. The bus has an oil leak but the oil level is still at an adequate level on the dipstick. bus is on a slight decline toward the nose. When I start the bus, I let it go thru its normal check cycle and when it gets to the oil cycle. the low oil symbol appears on the dash and a buzzer sounds, after starting the the bus, the low oil light disappears and the guage indicates that the oil level is exactly halfway between full and empty. Should i be concerned ? What things could possible be wrong. -Chris

[Robin97396]

The oil and engine needs help lights even come on in a car when you're starting it and go out immediately after starting. It sounds like the same thing since you've got the 24v electronically monitored version of the 5.9.

Have you tried parking it on level ground then restarting to see if the forward down angle makes a difference or not with the dash light?

[bigskypc50]

I am no expert, but I have never seen a gauge that tells you the oil level, now there is oil pressure gauges, when you turn the key to acc or pre start you should see all of your lights light up it's a self test if you will letting you see everything is working.

I don't know the a good oil pressure on the cummins but if it's at mid point at start up I would say your ok!

Originally Posted by brundige

I just purchased a 2000(built in 99) bluebid TC2000 with a 24valve cummins. The bus has an oil leak but the oil level is still at an adequate level on the dipstick. bus is on a slight decline toward the nose. When I start the bus, I let it go thru its normal check cycle and when it gets to the oil cycle. the low oil symbol appears on the dash and a buzzer sounds, after starting the the bus, the low oil light disappears and the guage indicates that the oil level is exactly halfway between full and empty. Should i be concerned ? What things could possible be wrong. -Chris

[Iceni John]

Are you talking about low oil level or low oil pressure? One is not necessarily directly related to the other. What exactly do your dash "Low Oil" light and buzzer denote - level or pressure?

Oil level is easy to check and should always be part of your pre-trip inspection before every time you start: note I didn't say low oil level, because if your level has increased then that's something critically important to check (maybe coolant or fuel contamination?). Nothing beats a good oil pressure gauge - lights and buzzers won't reveal trends and unusual patterns. I recently changed my original gauge for a Speedhut, so now I know exactly what's happening.

John

[brundige]

Originally Posted by Iceni John

Are you talking about low oil level or low oil pressure? One is not necessarily directly related to the other. What exactly do your dash "Low Oil" light and buzzer denote - level or pressure?

John

per the user manual: WARNING: An engine buzzer will sound to indicate low oil pressure and/or high coolant temperature.
Do not operate vehicle under these conditions. NOTE: Battery voltage alarm will beep if battery voltage
is below 11.5 volts or above 14.5 volts. The battery voltage gauge will remain “ON” until condition is
corrected.

I assume that its the oil, because the oil indicator is on when the buzzer sounds. I dont think that its part of the normal routine because the buzzer continues to sound until the engine starts and then everything seems normal guage wise.

[Rameses]

Originally Posted by brundige

per the user manual: WARNING: An engine buzzer will sound to indicate low oil pressure and/or high coolant temperature.
Do not operate vehicle under these conditions. NOTE: Battery voltage alarm will beep if battery voltage
is below 11.5 volts or above 14.5 volts. The battery voltage gauge will remain “ON” until condition is
corrected.

I assume that its the oil, because the oil indicator is on when the buzzer sounds. I dont think that its part of the normal routine because the buzzer continues to sound until the engine starts and then everything seems normal guage wise.

You do realize the engine doesn't produce oil pressure when it isn't running, right?

[cadillackid]

Originally Posted by Rameses

You do realize the engine doesn't produce oil pressure when it isn't running, right?

THIS!

that buzzer sounds when you are in pre-start for a couple reasons

1. to ttest the buzzer and Light, you should always have that buzzer and light when the key is on and the engine is Not running.

2. the sensor is not reading oil pressure because the oil pump only spins and pumps when the engine is running, its Normal not to have oil pressure when the engine is not spinning.

the oil Pump that builds pressure is not electric, it is mechanically driven by a gear or a chain, or on the crankshaft itself depending on the engine make and model. once the engine starts, the pump builds pressure..

the gauge on your dash is a measure of engine oil PUMPING, and not how much oil is actually in the engine. the oil in the engine you measure with the dipstick is how much is in it.. oil pressure is how much the poil is being moved around and pumped through the engine.. its normal for that oil pressure gauge to go up and down with RPM's.. it also usually runs Higher when the engine is cold because the oil is thick, once the engine warms up you may notice that gauge running Lower... the only time to worry is if that gauge goes way down or the buzzer sounds when the engine is actually running.
-Christopher

[DoubleO7]

Buzzer will also be sounding until your air pressure builds to a safe level.
If you have air brakes.

[brundige]

Awesome thanks ! Not sure if I should start a new thread for a new question but do you happen to know anything about the high idle? The switch does nothing. The guy I bought it from used the cruise control to set high idle but I have been unable to recreate the sequence he performed to get it to engage. Any thoughts?

Sent from my SM-G955U using Tapatalk

[Iceni John]

I would recommend having some good trustworthy gauges as your primary indicators of engine and bus health. Lights and buzzers are a useful adjunct to gauges, but they are NOT a substitute. At the very least have gauges for oil pressure, coolant temperature, transmission fluid temperature, and maybe for exhaust gas temperature. Obviously you would also have gauges for your air system, plus the normal speedometer and tachometer (or a tachograph). And have gauges with a 270-degree sweep - they have three times the resolution of the more common quarter-sweep gauges, so you know exactly what is happening instead of guessing.

If you don't know the health of your bus and its drivetrain while driving, you're essentially in the dark, and bad things sometimes happen in the dark! Good gauges are much cheaper than having your engine or transmission rebuilt because it overheated. I have the basic eleven up front plus nine more in the engine room, and for me that's a minimum to feel confident about what's happening, and to help troubleshoot if something's not right.

John

[Rameses]

Originally Posted by brundige

Awesome thanks ! Not sure if I should start a new thread for a new question but do you happen to know anything about the high idle? The switch does nothing. The guy I bought it from used the cruise control to set high idle but I have been unable to recreate the sequence he performed to get it to engage. Any thoughts?

Sent from my SM-G955U using Tapatalk

You should have two switches for the cruise, right?

Flip the on/off switch to the on position.

The other switch is used to set the rpm. Tap the top half of the switch once and you'll notice your idle jump to about 1,000 rpm. Now press and hold the top half of the switch to increase the rpm more. Release pressure on the switch when the rpm reach the point at which you want them to remain.

I have a rollback with an ISB in it and it doesn't have a high idle switch. I use the cruise to maintain 1,500 rpm while I'm using the pto.

When you're done and want to return to idle, simply flip the switch to off, or step on the brake pedal.

[Brad_SwiftFur]

Been out of town for a couple days ...

Right. First, some of the larger vehicles do have oil level sensors, so they do check oil level when started up. Typically they indicate if it's too high or too low. If it's somewhere in the middle, then I'd check the dipstick for a more accurate reading. A slight hill probably won't affect readings to any significant degree.

As for idling up the bus (as Rameses said) the cruise must be on, use the increase/decrease switch to adjust the RPM's. On that note, many modern diesel vehicles have idle shutdown timers, which will automatically shut off the engine after a few minutes of idling. The cruise function will override this shutdown; it has something to do with incomplete combustion if the RPM's are too low for extended periods, emissions and fuel building in the cylinders or something ... It also helps the AC cool better on many systems.