Oil Pressure Dropped to 0!!

[FPoitra]

OK, it was -37 F this morning. Had truck plugged in all night. It took several cranks of the starter to get it started, but it did start. Alot of grinds and grumbles for about 15 seconds and the oil pressure did go up. I depressed the accelerator pedal a little to get things moving. Then all of a sudden the check gages light came on and a chime sounded. I looked at the oil pressure gage and it was falling until it hit zero. It would not come back up!! I panicked and turned off the engine, waited for about 10 seconds and started it again. Oil pressure was OK. Used a stick to idle it at 1500 rpm. What happened and is there a fix?

 

[nickleinonen]

could be a bum switch. the gauge is a glorified idoit light. it is a 6psi pressure switch iirc. or maybe some frozen condensation in the oil got pumped up and blocked the switch for a moment? my engine made some awful noises with the 15w40 in it with the colder weather we were having [at start up when cold/not plugged in at work]. i have some thinner rotella 10w30 in there now [it's not approved by dodge but i don't give a hoot] and when the weather gets warmer, i'll go back to 15w40

 

[Bertram65]

I am curious why people say the oil presure guage in the 3rd gen trucks are basically idiot lights. It appears to be a varriable not just on and off. My indicated oil presure varies greatly depending on RPM and engine temp. I think the two numbers on the guage are 20 and 60, I will check tonight. If it is cold the oil presure is over 60, once the truck is warmed up the oil presure stays around 40 while driving, if I come to a stop the oil presure drops to an indicated 20, and goes right back up once the RPMs come up. It does not seem to be working like an idiot light to me. I have read that here several times and wonder what it is based on.

 

[LRoy]

It's a three position idiot light. No pressure (< 6psi), some pressure at low rpm, some pressure at higher rpm.



A quote from the service manual -



"The instrument cluster circuitry restricts the oil pressure gauge needle operation in order to provide readings that are consistent with customer expectations. Each time the cluster receives a message from the PCM or ECM indicating the engine oil pressure is above about 41 kPa (6 psi) the cluster holds the gauge needle at a point near the middle increment within the normal range on the gauge scale. "



Reading more, the manual seems to say that the sensor is a true sensor (not just an on/off switch triggered at 6psi) - it is just the pcm/instrument cluster that is "censoring" the gauge reading.

 

[nickleinonen]

here is a quote from the 2003 service manual for the dodge ram pickup trucks



page 8J - 32...

Engine Oil Pressure Message - The instrument

cluster circuitry restricts the oil pressure gauge

needle operation in order to provide readings that

are consistent with customer expectations. Each time

the cluster receives a message from the PCM or ECM

indicating the engine oil pressure is above about 41

kPa (6 psi) the cluster holds the gauge needle at a

point near the middle increment within the normal

range on the gauge scale.

that's why i'd call it a glorified idoit light eh





***edit***



woah, nice timing eh. same responce, same time, same quote :-laf

 

[FPoitra]

So how many people are switching their oil to a thinner viscosoty for the winter months. This is the suggestion that I got from a mechanic. 10w30 or 5w30??

 

[ThomasCook]

Does anyone know if a programming change could be made to "provide readings that are consistent with customer expectations" I expect a real oil pressure reading!

 

[rbattelle]

Ditto on the fake oil pressure gauge. I have an aftermarket unit installed, and I can promise you that it is only by pure coincidence every now and then that the factory gauge reads approximately correct. I agree with Tom: my "expectation" is to read oil pressure. BTW, I believe 75 psi is the point beyond which the needle will point to "110".



I didn't know what to do about going with a thinner viscosity oil for winter, so I called the local Cummins service center and asked their opinion. They said stick with 15w40 year-round in this area. Ambient temperature here almost never gets below 0, which is the apparent point at which you need synthetic 5w30. But I plug in at night, so the oil should be at least 30 or so in the morning. At work, I can't plug in, but during the day it's never below 0 (not so far, anyways).



If temps here were more frequently below 0 in the winter I'd either do what Nick did and switch to 10w30, or shell out the cash for 5w30 just for the winter months.

 

[GSpeed]

FPoitra , My truck did the same thing at the same temp, a couple days ago. I also got 2 codes P0514,P0524

SCARY!!!!

P0524 is oil pressure low

p0 514 is battery related on the faq list @no engine/trans. forum

Could anybody tell me what's the deal with that?

 

[JStieger]

Originally posted by rbattelle

Ditto on the fake oil pressure gauge. I have an aftermarket unit installed,

Do you have a mechanical or electrical oil pressure gauge installed? Did you just T this gauge off the same port where the factory gauge comes off?



Also, has anyone ever installed an aftermarket coolant temp gauge yet on the 03? - would be interesting to see how much the real temp gauge differs from the factory too.

 

[Bertram65]

Thanks for the clarification, I looked at the guage last night the numbers are 40 and 110, there are two marks, one to either side of the 40 so I assumed they were 20 and 60. I would be interested in where people have put the sender for an aftermarket oil presure guage.

 

[goodwid]

I also have had my idiot guage go to zero the last two mornings. I just let it ride and had a listen to the engine, 30 seconds later it came right back up (-40 or close enough, last two mornings) Both times it occurred when I had started the Engine and was on for about 20-30 seconds. The truck was plugged in all night, both nights. In fact, it will probably do the same in 10 mins, still -32 out.



Has anyone noticed how laud and ruff the engine sounds even at full operating temps when it is this cold out? Is this normal? It almost sounds like the pre-injecting is partially working. Any, thoughts?

 

[CATCRACKER]

back to the old rattle trap when it gets cold to help the warming process. i think it goes back to a single phased injection does not last to long. 1min or so.

 

[FPoitra]

I think I will just switch to 10W30 oil for the remainder of the winter. But I am concerned with putting in 10W30 oil approved for diesels. Any suggestions? I want to make sure it will not void the warranty if something would happen. (I changed oil only 2000 miles ago, so I am not changing the filter, just oil)

 

[FPoitra]

I forgot to add this thought. I actually wonder if the block heater really warms the oil as everyone says. The 12 or so quarts of oil sit in the oil pan, not the block. Unless there is a warmer on the oil pan, the oil must be thicker than molasses at -40 F. Am I right or not??

 

[ceastmen]

Originally posted by FPoitra

I forgot to add this thought. I actually wonder if the block heater really warms the oil as everyone says. The 12 or so quarts of oil sit in the oil pan, not the block. Unless there is a warmer on the oil pan, the oil must be thicker than molasses at -40 F. Am I right or not??

You are correct! and, in my experience, the thick oil is the culprit! See following explanation:

I've had this problem with super cold temps in gasoline motors, however it's not a function of motor type. In cold temps the oil is a lot more viscous (thick - obvious) and it gets pumped out of the oil pan into the various parts of the motor -but- is very slow to return to the oil pan due to the viscosity.



It is possible to pump all the oil out of the pan and have the pump loose pressure. You turn the vehicle off because the pressure light comes on - freak out a bit - wait for a while and re-fire the motor and have pressure because the oil returned to the pan while you were waiting.



I've had a'79 440 (6-quart motor) pump every ounce of oil out of the pan into the valve covers and valley and then loose oil pressure. The thick oil was the culprit. I waited and re-fired the motor and pressure was back up again. DO NOT leave a super cold motor idleing, after first fire, unattended.



Anyone else have this experience? Am I on the right track?

 

[rbattelle]

Originally posted by ceastmen



It is possible to pump all the oil out of the pan and have the pump loose pressure. You turn the vehicle off because the pressure light comes on - freak out a bit - wait for a while and re-fire the motor and have pressure because the oil returned to the pan while you were waiting.

Whether or not this is true, it sure sounds good!



For those who asked about the aftermarket gauge, I have an electric Isspro unit installed. Sending unit is tee'd off the oil pressure port pictured here. . I just used a 1/8-1/8 NPT straight adaptor and a street tee with one port plugged. Later I'll replace the tee with a cross so I can run oil pressure, temperature, and a bypass filter all from that one port. FWIW, I got all my fittings from www.swagelok.com . No afiliation... I just think they make fine quality fittings.



Since that port is rather high in the engine, I notice that the colder the oil is, the longer the gauge takes to register a reading on 1st startup. In warm weather, it's within a second or so. In very cold temps, it reads 0 for up to 3 or 4 seconds. Doesn't really bother me, though. I can speed it up by increasing RPM a little after she fires.



I, too, wonder how effective the block heater is on the oil. Perhaps down the road I'll invest in a good quality oil pan heater. I'd also like to invest in a higher-power block heater.

 

[ceastmen]

[/QUOTE] I, too, wonder how effective the block heater is on the oil. Perhaps down the road I'll invest in a good quality oil pan heater. I'd also like to invest in a higher-power block heater. [/B][/QUOTE]





In my experiences I've noted block heaters only heat the engine coolant, which is their intent, and have little effect on the oil temperature. I've never owned a diesel before but have broad experience with all things mechanical on vehicles and I'll bet the engine heater does not affect the oil temp on our cummins motors.



I've seen magnetic mats that stick to the oil pan (mat contains heating element, plugs into 120 Vac) and heat the oil by convection. I don't have my 2500 CTD-600 yet (on order) but I'll bet the factory engine heater does nothing for the oil. Try a local Napa or Checker (kragen, schucks etc. ) to see if they've heard of something like it.



Does anyone else have a better way to heat the oil?



Good luck!

 

[nickleinonen]

Originally posted by FPoitra

I think I will just switch to 10W30 oil for the remainder of the winter. But I am concerned with putting in 10W30 oil approved for diesels. Any suggestions? I want to make sure it will not void the warranty if something would happen. (I changed oil only 2000 miles ago, so I am not changing the filter, just oil)

the oil i used is rebranded shell rotella 10w30. i had it on good word that the oil was rotella, and the smell of it proved it :-laf. if you look at a new bottle of 10w30 rotella, it is approved for most diesel engines and is CI rated if you care about that.

 

[Crunch]

I don't think so...

Originally posted by ceastmen

In my experiences I've noted block heaters only heat the engine coolant, which is their intent, and have little effect on the oil temperature. I've never owned a diesel before but have broad experience with all things mechanical on vehicles and I'll bet the engine heater does not affect the oil temp on our cummins motors.



I don't believe that is correct. I regularly use a block heater when it gets near freezing (coldest so far this winter has been 24*F) and when I unplug it in the morning every part of the engine is warm. While the block heater begins by heating the coolant, once the coolant reaches the maximum temperature the heater can get it to the heat will radiate and transfer to the rest of the engine. I haven't put my hand on the pan after unplugging, but I bet it will be at or near the temperature of the cast iron parts on the engine.



Think about it: If the block heater heats the coolant, where does the heat travel as it dissipates? It has to transfer along the engine block, oil, and other engine components, all of which have varying degrees (<-pun) of ability to further transfer and retain heat. The plastic valve cover probably doesn't retain heat very well. Same for the rubber hoses. But any metal component, especially thick cast metals will retain heat well as long as the block heater is resupplying lost heat.