Oil pressure drops to zero at idle

160

Asked by Jasonm13 Jun 09, 2015 at 02:04 PM about the 2001 Dodge RAM 1500 SLT Quad Cab LB 4WD

Question type: Maintenance & Repair

When the truck is idling it Has no oil
pressure and the check gauge light
comes on but when I raise the rpms
it goes back to 40 I rebuilt the engine
650 miles ago and it has a new oil
pump could it just be the oil pressure
sensor?

30 Answers

545

could be your oil pressure sensor, the oil pressure gauge or simply the oil pump bad. I would start with the simplest first. Test the pressure sensor and pressure gauge. Also when you rebuilt the engine, did you clean out all sludge and change the oil pump?

29 people found this helpful.
160

Yes I did clean out the sludge and the oil pump is new how do I test the sensor and gauge?

16 people found this helpful.
70,075

first take off the sender...start/idle for 2 seconds .did /does a stream of oil shoot out//if so first replace the sender.

21 people found this helpful.
545

Depends on the car. But usually people first check continuity on the harness first, then check resistance on the pressure sensor and then resistance on the gauge. My 1988 4runner was doing the same, once engine warmed up, the pressure would read 0. In my case the pressure switch is cheap so i did trial and error. Just replaced it. Didnt work, i checked the harness and it had corrosion on the ends. Cleaned them out, got little better. At the end it was the gauge on the instrument cluster. Needed a better clean ground.

24 people found this helpful.
830

Just FYI...I am having the exact same issue with my 2002 Dodge Ram 1500 (91,000 miles). I have replaced the oil sending unit (and had a bad solenoid replaced on the transmission). Thought it was fixed, but began happening again. (mine will also begin to heat up when this is happening) Talked to a trusted mechanic in town, and he informed me of another customer having the SAME problem with his Dodge pick up. He recommended I call the Dodge house. They said theyre unaware of this being a standard issue, and it will cost me $200 just to diagnose the problem. I suggest looking at some of the other message boards as well...and if anyone figures out what the deal is, Id LOVE to hear it!

55 people found this helpful.
160

I got a 1985 dodge ram charger with a built 318, cam, intake, heads, carb, crank, pistions the whole 9 yards and I was driving it to school and it was pretty early in the morning and the oil pressure is at 40 when its idling and when I get into it its usally between 80, and 60 it jumps all over well it was back firing through the carb I think it was running to lean maybe because it was a cold start I have no Idea, but now the oil pressure jumps all over

16 people found this helpful.
800

I’ve got a 2005 Dodge Ram 1500 5.7L. The oil pressure gauge started doing the same thing to me this morning. It reads normal when I start it up, but then drops to zero after a min. I’ll reply if I find out what it is.

80 people found this helpful.
200

I have a 2003 5.7 hemi Laramie, edition 135.000, miles and mine drops at different times ,just when ever it feels like it ,please if anyone figures out what it is i would love to know ,my mechanic friend said if it's not making a lot of noise it's probably not the pump,to check the sensor first ,a d it doesn't over heat!!

20 people found this helpful.
130

I have a 2000 dodge dakota 4.7 with the same issue it has a noisy lifter and it takes a while to get oil pressure when 1st started then when I drive it drops to 0 for a minute or so then goes back up for a minute or so

13 people found this helpful.
410

I found out on the 04 Dodge Ram hemi in it wasn't the oil pan it was the pickup tube inside the oil pan fix my problem thank God!

41 people found this helpful.
410

Mine's been doing it for four years when it heats up and you take your foot off the accelerator. A mechanic said every thing checked out ok but it may be the wiring harness. Engine never over heats. Just reads check gauge. Step on the gas goes back to normal ? Beats the hell outta me!!!

41 people found this helpful.
190

My truck runs fine for few mins then check gauges comes on no oil pressure n then my truck shuts off replaced pressure switch n head starter n thermostat can't get oil pressure any advice

19 people found this helpful.
270

This has happened to me for two Dodge engines, 293 3.9L V6 and my 318 5.2L V8, and after changing the trans cooler, clutch fan and water pump it went away. I also had already changed the oil pressure sensor on both along with the wiring harness, and the issue did not go away. The vans (not trucks in both my vehicles) both would shut off when the gauge would read empty when coming to a stop. Never would either engine overheat. It was as if the engine was not getting what it needed as if it was about to overheat but still would not. If I never changed out the clutch fan and went ahead and changed the water pump, of course it would have eventually overheated. The clutch fan needed replacing, and that’s when the issue went away. I went ahead and put spacers in also, replaced the trans cooler because they’re about $40-$50, and did the water pump on both. Should be good after that. Hope that helps.

18 people found this helpful.
270

I forgot to mention my 3.9L has 450,000 miles, and my 5.2L has 310,000 miles.

9 people found this helpful.
40

I heard that the 5.7 hemi at around 100k to break valve spring and drop valve i have changed oil / filter that helped a little motor sounded bad So going tear apart see old oil had metal shine in it that's not good

4 people found this helpful.
50

Dont know if it is the same as some of the gords but when the battery starts to go bad it will do thia same thing I replaced the battery and it fixed the issue talked to Ford and they said that on test the battery will read good but it is programmed in the computer of the vehicle to do this when a certain part of the battery starts to go bad

5 people found this helpful.
610

I have a 2000 Ram 1500 that I've had this on again, off again, oil pressure problem much like some of you here. This truck has been in the family since it was new. So I know it was taken care of. I can tell you that DODGE should own this problem in some cases. I was furious when I pulled the oil pan to replace what I thought was a bad oil pump. Turns out that some idiot engineer at Dodge thought is would be a great idea to restrict the size of the oil pump pickup screen. They put essentially a cone over the screen and left about a 3/4" hole. The pictures below show my sheet metal skills had already started cutting out the cone. Don't criticise too much if you've never used hand shears to cut a hole this small... ;)P But what you can see is a screen that is completely clogged! IMO, this is a product of sludge build-up in the motor, breaking down, and stopping up the pick screen. Assuming you have ruled out gauge and electrical problems, my advice would be to replace your pick screen with one that doesn't have a cone. Then run Seafoam, or your favorite cleaner, through the oil system and clean out as much of the sludge as possible. Run a decent but inexpensive oil with your cleaner every 200- 500 miles and then dump the oil. Do this several times over the next few oil changes making your change intervals longer and longer until your back to every 2-3K miles. If you find that during this process your gauge is dropping to zero again you may have to go back and clean the screen out. Sucks. But Dodge has a problem. The oil should not be breaking down this fast under normal change intervals. I wonder if Dodge's design is running these motors too hot causing the oil to break down prematurely. I may lower my thermostat temperature and see what happens. Either way, good luck to everyone. This is a very frustrating problem to deal with and I hope my experience helps someone.

61 people found this helpful.
110

Has anyone changed their plenum plate? I heard that was a major issue as well for oil gauges dropping to zero at idle. Mines doing the same.

11 people found this helpful.
70

I have a 1997 dodge 1500 5.9 great truck. 280k miles. Couple days ago the oil light started to come on here and there at low rpms etc. Now I noticed oil pressure is zero at no speed in gear... put it in park and it goes away. Drive at speed it goes away.. mmmmm???? I was thinking oil pump. Hopefully it's just the oil sensor.

7 people found this helpful.
50

I have a 98 dodge Durango 4x4 with the 5.2 magnum v8 super charged camed and when its idling its fine but when it gets warmed up it drops and even when I put it in gear and when I'm driving down the road and when I took the supercharger off it was doing the same thing and can't figure it out

5 people found this helpful.
120

I have an 05 ram 1500 and had the same thing happening. The pressure was dropping on idle then would go back to normal when rpms would go up. Ended up being a quart overfull soon as I drained the amount out it quit the up and down.

12 people found this helpful.
30

05 Dadge Ram 1500 4x4... Same issue.. anyone figure out a definite answer?

3 people found this helpful.
60

2003 1500 5.7. Same issue. Here is what I have done: Replaced: oil pump, pickup tube, a slew of sensors including 4 oil pressure sensors, tcm, replaced instrument cluster. No sludge. Even tried to tune it set at higher RPMs. Still doing the oil pressure drop. I have tried everything I have read on these and other forums. Nothing works! If there is something I'm missing, please let me know!

6 people found this helpful.
160

So I got a 02 dodge ram 1500 4.7L 103k miles that i thought had a blown head gasket. When i got the heads off i saw they were cracked. Went to pick n pull and got heads off a 4.7L Durango (same heads) replaced all the gaskets and cleaned her out really good. When I got her going I had low oil pressure at idle. So I ran sea foam to clean the sludge I couldnt get out, drained the oil, replaced the pickup tube, oil pump, and pressure sensor (switch). Still low oil pressure. Switched to a thicker oil, still low oil pressure. Only ever when I'm below 1k rpm. So I now have the oil pan back off, I'm replacing rod bearings, and I may even attempt to drop the bed plate and get the main bearings if I can. I'm also going to change my idle air control on the throttle body. So far all these bearings look good :( And my current self can hear my future self laughing that i am even saying this but no, i did not hook up a mechanical gauge yet (dumb) When I get her all back together I'll report on what I find. And I'll definitely check with a real guage Only question I really have is, how often is the dash wrong? Both the new sensor and the old sensor had the same results, engine doesnt sound different when the dash is freaking out, engine doesnt over heat.

7 people found this helpful.
160

I FOUND MY ISSUE! I'm the guy with the 2002 4.7 dodge ram 1500 with 103k. I dropped the oil pan and replaced the rod bearings, but they all looked good, and the crank shaft looked good also. I decided to pull into the timing cover again, and discovered that my idler timing sprocket (center gear, largest gear) didnt have a bolt in it, somehow I lost it because I didnt have any left over parts. I also looked at the timing tensioners, they each have an oil hole at the back where they bolt in. My pensioners were good but if you are truly dropping pressure and aren't sure why, I would look under the oil pan and timing cover. I have gotten the crash course on this 4.7. I really hope this helps, I was really stuck. Good luck out there guys

9 people found this helpful.
35

I was having the same issue as many of you. 2003 Durango with 5.9L. Oil pressure is fine until it warms up, then drops to near 0 at idle. Hooking up a pressure test gauge confirmed 4 PSI. Higher RPM brings back the oil pressure. This was not an issue before I had my engine rebuilt, but after rebuild, I I have this problem. Pulled off the oil pump and manually tested it, no problems there. ISSUE WAS MISSING OIL GALLEY PLUG! Machine shop missed putting one of the plugs back in after machining and cleaning the block. Since the plug is inside the block, I couldn't visually see anything missing. The specific one missing in my case was just under the distributor. There are two access plugs in the back of the block (hex keyed), remove the one on the left, and inside there is where the missing oil galley plug went. Hope that helps someone!

3 people found this helpful.
140

Same issue with 5.7L Hemi remanufactured engine installed September 2020. On start oil pressure at 14psi and immediately (within less than 10 seconds) drops to 0-1psi and oil indicator light comes on. Revving engine boosts oil pressure, which drops back to zero when letting off on the accelerator. Note: This occurs when climate control is "off"…..If climate control is engaged (A/C or Heat), have noticed this delays oil pressure drop until vehicle is at curb idle and normal temperature. First notice occurring with vehicle on slight incline; recurring when flat as well. There was no engine oil loss observed and oil was absolutely clean following engine installation. Dealer has been able to replicate issue repeatedly....and after 2 days of diagnostics they had to submit online case to factory for suggestions. Noting that this was with a manual gauge showing normal pressure(s) at the top of the engine and checking wiring and replacing the oil pressure sending unit as well. My naive question at that point was.....is the oil pickup positioned correctly or is an oil galley plug missing? [similar to other posters questions]. Answer this morning: Vehicle fixed at dealership after dropping oil pan and looking at the oil pickup. Issue and resolution: O-ring on oil pickup split/slipped out of position during assembly of engine.......so no oil pressure unless under initial engine load requiring non-idle rpm. New O-ring installed....problem solved with nice and consistent (not zero!) oil pressure at curb idle and under acceleration and at normal operating temperatures. Thought this might be of use to someone as feedback from the factory was apparently to check for this issue.

14 people found this helpful.
20

Just did a complete rebuild of my 2013 5.7 hemi and having oil pressure problems also.

2 people found this helpful.

If all else fails and you know the bearings are correct and electrically it is sound then you could have had the wrong cam bearings installed in the block. Usually when it is a issue of incorrect bearings what you will see is great oil pressure when you start it up cold but after 5 to 10 minutes when things start warming up and the oil warms up them your oil pressure will start falling off.

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