# 05 Ram Oil Pressure Gauge Question



## Plow Dude

Every morning when I start the truck the oil pressure gauge never goes up and my check gauges light comes on. So I have to start it a second time before it reads. This gets very annoying having to start my truck two times in a row. It seems to do it more often when it is cold outside.

Does anyone know what causes this? 

It is an 05 Ram 2500


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## V_Scapes

This just happened with the truck pictured in my sig. Its most likely the oil pressure sending unit. What happened with mine was when i would just start to drive it after warming it up alittle id let off the gas to coast down a hill or come to a stop and the oil gauge would drop to 0 and the chack gauges light would go ballistic. try the OPSU first, its only a $20 part that screws into the block i believe...good luck.


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## RacingZR

Mine just started doing the same thing. Let me know what you find out. I haven't had a chance to post it on the Dodge forums yet to ask those guys.


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## woodchuck2

Be sure you guys are running OEM filters too. I saw many engines at the dealer come in for no oil pressure and some were already knocking due to after market oil filters. I do recall some issues of senders too.


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## RacingZR

Can anyone tell where the sending unit is located? I wanna take it out and bring it to the dealer so I know I get the rigfht part.


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## V_Scapes

the unit is kind of in the bottom left front of the block if your looking at the front of the truck. if you just ask them for an oil pressure sending unit for your type of truck they should have it. 
Ive run wix filters in my trucks before and ive had no problems but lately I use the mopar ones. are you talking about cheap oil filters?


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## RacingZR

Yep, found a schematic. looks like it is just above the oil filter. Thanks.


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## woodchuck2

When i worked for Dodge they were very specific about using OEM filters. They denied engine warranties on 2 different Cummins that came in for no oil pressure and lower engine knocking. You ever heard of a Cummins with a rod knock, now that is loud!! Both engines were just over 100k and had aftermarket oil filters on them. Dodge was willing to good will the engines if they had OEM filters but not with aftermarket. I also saw a couple Hemi's and 4.7's with oil pressure issues and Dodge blamed the aftermarket filters.


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## V_Scapes

Thanks for the info, ill try and stick to Mopar from now on.


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## bltp203

This happens to both my Dodges in the winter only. I have just learned to deal with it. But if someone cures it with a new sensor, please let us know.


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## D2 Cat

I had the same trouble on my '01. I was driving from K.C. to Ft. Collins. Was in the middle of no where when the check gauge light came at a stop light. I listened for any odd thumping or raddle and since there was none I went on. Happened once more coming home. I replaced the OP sending unit. Now it actually shows more pressure then the old unit!

First time it will really get your attention!!


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## V_Scapes

Yea my oil pressure reads alittle higher also. the problem was that not only was it showing bad oil press. but my unit was also leaking oil that I wasnt aware of.


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## RacingZR

No oil leaks on mine but there is some rust on the threads and the block. Been winding the PB Blaster to it for a couple days. Picked up the sensor today. Will definitely let you know if it fixes the problem. $24 at the dealer.
Remove the air filter housing and its right there. 10 minute job if the old sensor comes out easy. Stay tuned.......


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## Mopard

...


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## NICHOLS LANDSCA

woodchuck2;1249683 said:


> When i worked for Dodge they were very specific about using OEM filters. They denied engine warranties on 2 different Cummins that came in for no oil pressure and lower engine knocking. You ever heard of a Cummins with a rod knock, now that is loud!! Both engines were just over 100k and had aftermarket oil filters on them. Dodge was willing to good will the engines if they had OEM filters but not with aftermarket. I also saw a couple Hemi's and 4.7's with oil pressure issues and Dodge blamed the aftermarket filters.


They may have denied the warranty but they couldn't have blamed the filter that is illegal, if the filter meets spec you can run it. If you are REQUIRED to use X part the manufacturer would have to supply it FREE.


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## RacingZR

Replaced the sending unit/sensor this morning. It's a 10 minute job that took me 20 because I had to use an adjustable wrench.........Didn't have any sockets or wrenches over 1".

1) Get under the hood. Take the air filter housing out after loosening the clamp for the hose on the intake. The entire assembly pops right out.
2) You'll see the oil sensor on the front of the block just above the oil filter, very easy to get to. Unlock the electrical plug by pushing the red tab "out" to unlock, pull plug off from the sensor.
3) Remove old sensor with socket or wrench (you can buy a "oil sending unit socket" at any auto parts store). Have the new sensor ready to thread in as you will lose some oil out of the block once the old sensor is removed. Not much at all if you have the new one ready to go in.
4) Thread in the new sensor, you can do about half of it by hand. Thread in until there are only 2-3 threads left (just see how far in the old one was, that's what I did). The new sensor should have had some thread sealant already applied but make sure.
5) Throw some dielectric grease on the connector, plug it back in, lock tab in place and reinstall the filter housing. FYI- Its easier to reinstall the air filter hosuing if you take the air filter out to line up the bottom holes.
6) Start truck and check for leaks.

For mine, it only acted up when it was very cold out (like when air temp was around 0 F). If we have another cold morning I will check it to see if that was the culprit. Pretty simple, $24 and 20 minutes.


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## RacingZR

About 7 degrees this morning and the oil gage went up right away. I'd say it's fixed with the new sensor.


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## V_Scapes

Very nice. im not much of a mechanic but im happy i could help.


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## dufresne

Thanks for the info guys, My truck only has 70K miles on it and stupid check gauge light kept coming on at idle. Indicating 0 oil pressure. Changed oil first to eliminate that as the cause. Didn't fix the problem. So I went and got a new Oil Pressure switch at the parts store cost $24. Replaced it and now Im all ready to go again. It took less than 10 minutes to replace. Its right above the oil filter, open the hood unplug the wire, unscrew the OPS and reverse the proceedure with the new switch. didnt even get any oil leaking out of the block while the switch was out.


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## Burns13

Did you replace the opsu with a oem one or one from a parts store?


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## John_DeereGreen

6 year old post....


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## Randall Ave

John_DeereGreen said:


> 6 year old post....


Maby the parts on backorder


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## Burns13

Who cares how long the post is. Its still a problem


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## Randall Ave

Burns13 said:


> Did you replace the opsu with a oem one or one from a parts store?


Get the part from a dealer, the aftermarket electrical parts leave much to be desired.


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## Burns13

Thanks i already have it ordered and its coming tomorrow, did that today. I guess what i was really trying to figure out was if that doesnt work did anyone run into any other solutions


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## Randall Ave

If you replace the sender, and still no reading. Time to install a mechanical gauge and see what's wrong.


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## Burns13

I have put a mechanical guage on the filter housing and it all checked out. I also sent off a oil sample and it checked out. Have you had any issues with parts from a parts store that wasnt oem just not working? Ill see what happens tomorrow I just dont understand why my truck runs fine and all but the guage is still acting up


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## Richh56

My 99 Ram 3500. 5.9 lt does this too. Mostly as I come to a stop at a redifferent light. Gage bottoms out and whistles and bells go off.. pick up the idle speed a tab and right back to 40 psi. I thing in my case it's just my sensor. The truck has never knocked


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## prezek

My mechanic put a gauge on mine and the pressure wasn’t really falling out. The gauge on the dash is more of an idiot light than an actual reading. If the pressure fell slightly at a red light, the dash gauge would read zero.


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## koonta54

This was a problem I had for quite a while, stopped into the dealer for an unrelated problem and he updated or reflashed the computer [didn't know I had one] and gauge has been good since. '98 Cummins


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