Low oil pressure
Thread Starter
|
Registered User
Joined: Dec 2017
Posts: 1
Likes: 0
Low oil pressure
2000 Dakota 4.7 170k 4x4
So i haven’t had the truck but for 2 weeks. Bought it just like it is i just didn’t take enough time while looking at it. I am concerned that i made a mistake an will find my self loosing money.
-low oil pressure
upon cold start an warming up the pressure stays in the normal range but above the 40 mark, I’d say 60-70. On a 30 minute drive without stopping to a complete stop and parked. Not all the time, sometimes, i can watch the pressure fall below 40 to about 25-35, also the idle will drop to a slightly lower rpm. When it falls it stays steady, some white smoke will appear from the exhaust. If I give it gas while parked i can see the oil pressure climbing back to where it was an no more smoke once i blow it out. It has no catalytic coverter, not sure if this effects oil pressure? I do have one I’m going to have installed. No smoke when I’m driving down the road, only at idle.
-oil leak
had a shop change the oil, from what he said it looked fine. I mentioned a oil leak to him to see if he could pin point it. After I cleaned it an drove it, seems to me it’s coming from the passenger side head gasket only. Wheeping out slowly. I do not smell coolant or do i have any overheating issues.That whole side of the motor is full of dry/wet oil residue, hard to see what else could be leaking if it is, idk yet. 250 miles an oil level is the same. I changed the plugs an plan to inspect those soon for abnormalities.
i did have a code for the idle position sensor. I think it’s a generic version the previous owner replaced. I took it off, cleared the code an the idle seems to not be fluctuating as much as it was.
From some research i read
bad rings
bad bearings
oil pickup tube in the oil pan is clogged
bad oil pump
motor is gunked up
Haven’t found the exact same diagnosis I’m giving on any forum yet. Similar one yes but they all end with costly rebuilds or swaps.
What do i do to figure out the real problem?
So i haven’t had the truck but for 2 weeks. Bought it just like it is i just didn’t take enough time while looking at it. I am concerned that i made a mistake an will find my self loosing money.
-low oil pressure
upon cold start an warming up the pressure stays in the normal range but above the 40 mark, I’d say 60-70. On a 30 minute drive without stopping to a complete stop and parked. Not all the time, sometimes, i can watch the pressure fall below 40 to about 25-35, also the idle will drop to a slightly lower rpm. When it falls it stays steady, some white smoke will appear from the exhaust. If I give it gas while parked i can see the oil pressure climbing back to where it was an no more smoke once i blow it out. It has no catalytic coverter, not sure if this effects oil pressure? I do have one I’m going to have installed. No smoke when I’m driving down the road, only at idle.
-oil leak
had a shop change the oil, from what he said it looked fine. I mentioned a oil leak to him to see if he could pin point it. After I cleaned it an drove it, seems to me it’s coming from the passenger side head gasket only. Wheeping out slowly. I do not smell coolant or do i have any overheating issues.That whole side of the motor is full of dry/wet oil residue, hard to see what else could be leaking if it is, idk yet. 250 miles an oil level is the same. I changed the plugs an plan to inspect those soon for abnormalities.
i did have a code for the idle position sensor. I think it’s a generic version the previous owner replaced. I took it off, cleared the code an the idle seems to not be fluctuating as much as it was.
From some research i read
bad rings
bad bearings
oil pickup tube in the oil pan is clogged
bad oil pump
motor is gunked up
Haven’t found the exact same diagnosis I’m giving on any forum yet. Similar one yes but they all end with costly rebuilds or swaps.
What do i do to figure out the real problem?
Registered User
Joined: Apr 2014
Posts: 14
Likes: 0
Low oil pressure is usually caused from worn bearings or worn oil pump (Excess clearance between bearing surfaces)
Blue/grey smoking (oil related) is usually caused from:
1) worn/sticking piston rings - usually will smoke all the time hot or cold but may burn off at speed. Depending on wear it could be improved from an engine flush. Also synthetic oil may help it, closely watched/inspected and maybe changed more often as it breaks down sludge.
A compression test will tell you the condition of the rings/engine and whether or not a rebuild will be necessary.
2) leaking valve guides/seals - usually will puff smoke at start up as the oil will leak down the guides while the engine is off and burn when started. usually when running at speed it can be burned off and not show in exhaust.
Pulling a valve cover may show you a general condition of how the engine was maintained. If it is gunky/clogged chances are the engine oil wasn't maintained and regardless of what you do it will need to be overhauled eventually. An engine flush and thicker oil can improve it a little, maybe enough to get you through till your better able to afford a rebuild or swap. The important thing you will have to do is to watch the oil level to see how much you burn of and maintain the level so it doesn't get to low.
A Catalytic converter will not affect oil pressure or smoking these are usually mechanically related. Don't install a new catalytic converter on a smoking engine, it may just cause the converter to go bad faster.
Any wet surface is a leak from something and the source should be found and corrected.
Black smoke is fuel related.
White smoke is coolant related.
Blue/grey smoking (oil related) is usually caused from:
1) worn/sticking piston rings - usually will smoke all the time hot or cold but may burn off at speed. Depending on wear it could be improved from an engine flush. Also synthetic oil may help it, closely watched/inspected and maybe changed more often as it breaks down sludge.
A compression test will tell you the condition of the rings/engine and whether or not a rebuild will be necessary.
2) leaking valve guides/seals - usually will puff smoke at start up as the oil will leak down the guides while the engine is off and burn when started. usually when running at speed it can be burned off and not show in exhaust.
Pulling a valve cover may show you a general condition of how the engine was maintained. If it is gunky/clogged chances are the engine oil wasn't maintained and regardless of what you do it will need to be overhauled eventually. An engine flush and thicker oil can improve it a little, maybe enough to get you through till your better able to afford a rebuild or swap. The important thing you will have to do is to watch the oil level to see how much you burn of and maintain the level so it doesn't get to low.
A Catalytic converter will not affect oil pressure or smoking these are usually mechanically related. Don't install a new catalytic converter on a smoking engine, it may just cause the converter to go bad faster.
Any wet surface is a leak from something and the source should be found and corrected.
Black smoke is fuel related.
White smoke is coolant related.
Last edited by canopus; Dec 4, 2017 at 05:04 PM.
Champion
Joined: Oct 2013
Posts: 3,771
Likes: 447
From: Atlanta
Well first you gotta figure out if the gauge is telling you the truth. You can hook up a manual oil pressure gauge to test the pressure. If the pressure is good on the mechanical gauge, then it might be that your oil pressure sender is failing. That would be the best case scenario. I've replaced mine a few times....https://dodgeforum.com/forum/2nd-gen...sure-drop.html It's underneath, near the oil filter.
The smoke could be caused by worn valve stem seals. I replaced mine back in 2020. https://dodgeforum.com/forum/2nd-gen...tem-seals.html
The smoke could be caused by worn valve stem seals. I replaced mine back in 2020. https://dodgeforum.com/forum/2nd-gen...tem-seals.html