So, my oil light comes on after startup like usual then shuts off. Anywhere from 2-5 minutes of the vehicle running light comes back on and does not shut off unless I restart the vehicle. Have changed oil pressure switch and oil pressure is reading in the normal range…any suggestions???)
05 dakota with 175000 kilometres
Did you install an oil pressure gauge in place of the oil pressure sending unit to test for oil pressure?
Tester
Listen to Tester since getting your oil pump pressure tested may help save your engine.
Yes, agree with both posted answers. Sounds like as the engine gets warm, the oil thins enough to drop the oil pressure into the danger zone. Run it long enough like this and the engine will need to be rebuilt or replaced. Get this checked as soon as possible!
Yes, I have took it to the shop three times for the same problem and they can’t figure it out. Oil pressure is in the “ok” range when tested. I’ve been doing my own research because my mechanic can’t figure this out. I have read that it could be rod wear, oil pump going or a wiring issue. Also, when I start my vehicle there is a slight knock which goes away within a minute. The mechanic added some additive for this and it has settled the noise down some. But I am lost maybe I need to bring it to another shop.
Also, Mustangman…as the engine gets warm and thins the oil enough to drop the oil pressure to the danger zone wouldn’t the light stay on after i restart the engine immediately after?
Thanks in advance…
Since it happens all the time, have them put a gauge on it ane read the pressure. If the pressure really drops then you can look at rings, pump.
Ok, just came back from the shop and the oil pressure readings are all good other than on initial startup. So, before he rips off the oil pan (big job), he put some transmission fluid in the oil to see if it will clean what he thinks is a blockage somewhere… Told me to drive it for a week and to take it for a nice long drive at some point as well. Right now he said process of elimination. But pressure good just not at startup.
If you feel confident that the engine is getting adequate oil pressure, you might disconnect and insulate the wire to the oil light sensor. Run or drive the truck for the requisite time until the light ordinarily comes ‘on’ and see if the dash light still comes ‘on’ after that time. This would determine if there is a circuitry problem or a true signel from the pressure switch.
Alternately, you could get the light to come ‘on’; leave the engine running; disconnect the sensor wire; and do a continuity check on the switch. If the switch is actually giving you a false negative, you have narrowed down the problem.
It is a little early in the life of this engine at 100k miles for bearing or pump problems to occur.
Let us know how you progress on this trouble shooting.
@Shannon11, yes the pressure should still be down on a hot restart and the light should still be on right at restart.
Low pressure at start up sounds like the oil is draining back down past the oil filters anti-drainback valve or back through the pump. The noise you hear is the lack of oil pressure at startup causing a rod to knock. That is not a good sign in any event. The low oil pressure is damaging the engine or the engine is already worn out and the light is just telling you “time to change the bearings!”
Additionally, If a gauge shows the pressure is in the OK range, why is the oil light on? The oil light is a dumb switch that turns on when the pressure is below a certain safe point. That is how it works. This info does not jive with the oil pressure gauge info. Did he gauge it from the oil pressure switch’s port? Or some other spot in the engine? Readings can be very different front to back.
This vintage of Chrysler products had a great many faulty oil pressure sending units.
I will keep you guys posted. Going to take it for a second opinion…couldn’t hurt.
Thanks for the comments and suggestions.
What engine does this Dakota have?
Tester
@oldtimer Yes, my 1965 Dodge Dart had it fail by way of staying on. Better than not working at all of course.
Just a wild guess here, could you have something in the oil pan like thick amounts of sludge that gets pulled up to the oil pump and blocks the flow ? When you shut the engine down this gunk falls off to the pan and starts itself all over again. One other thing, how are the oil drain holes in the heads ? if these get plugged the oil cannot return back to the pan and cause a low oil level.
I once pulled the valve covers off an old neglected Ford 302 and there must of been almost a quart of oil in each head…what a mess…The drain holes were totally clogged. Let us know what you eventually find as a lot of owners ask for help and never let us know what the outcome was.
This way we can use that info if a similar question comes up.
I tend to agree with Howie32703. Maybe the screen on the oil pump pickup is half clogged with coked engine oil. Very low miles engines suffering from this have been known to grenade themselves.
You might consider having the oil drained and a probe of some sort (loop in the end of a piece of coat hangar wire will work) and rake the bottm of the oil pan through the drain hole.
If the loop is removed and covered with what appears to be black, hardened motor oil then I would suggest dropping the pan and checking that screen before the engine does fail.
Which Engine Is In This Vehicle?
I see a bulletin pertaining to 2005 Dodge/Chrysler/Jeep vehicle oil viscosity requirements for 12 engines, ranging from 5w20 to 10w30. It wouldn’t hurt to be sure the correct oil is being supplied.
CSA
If the vehicle has the V6 engine, what might be happening is the plastic on the timing chain guides is coming apart and falling into the oil pan. These plastic pieces then sit at the bottom of the oil pan. Then when the engine is started, these plastic pieces are slowly drawn towards the oil pump pick-up screen eventually blocking the screen. Then when the engine is shut off, these plastic pieces fall away from the pick-up screen and sink back to the bottom of the oil pan. And the process starts all over again.
One way to determine if this what’s happening is, drain the oil and if any plastic pieces come out with the drained oil.
Tester
Hey everyone…it’s a 4.7 engine. I am bringing it to the Dodge dealership to have it diagnosed on Friday. Problem is still present. Chatter when I start the vehicle still present as is oil light on initial startup. Weird thing is that beyond this issue truck is running better than it ever has.
Side note, Me and my wife bought a new vehicle so this was actually her truck, I sold my 94 Ford 351 (102000 original kilometres) because I thought it made sense (newer vehicle and 4 by 4). I know she hasn’t maintained it the way she should have so hopefully I haven’t got rid of my truck for a lemon.
I’m assuming Dodge would be the right place to go???
“when I start my vehicle there is a slight knock which goes away within a minute. The mechanic added some additive for this and it has settled the noise down some.”
Sounds like some damage has already occurred