Will this cause low oil pressure at warm idle

It is possible that the low oil pressure when idling in your 94 Dodge Dakota 3.9 could be caused by either a faulty oil pump or a faulty oil pressure sending unit. It is difficult to accurately diagnose the issue without further information and a proper inspection.

this means a mechanical gauge test is required to check actual pressure warm idling if low below 20 psi then the oil pressure pump relief is stuck open or engine bearing are worn

Low oil pressure at idle can be caused by an engine with worn rod or main bearings due to (usually) high mileage . This however does not mean the engine is still not serviceable as long as the oil pressure is low only at idle. The pressure should at minimum get into the normal range at anything above idle speed.Not much oil pressure is really necessary at LOW speed. At low speed, as long as there is oil getting to the bearings, even at low pressure, you are OK. In a high mileage engine the oil pressure is often low at idle simply because the oil pump is turning slowly and cannot maintain higher pressure between the larger than normal crankshaft and bearing clearances. As speed increases the pump turns faster and supplies more oil and the pressure should go higher. Low pressure as long as it is only at idle is not a problem. However at higher speeds the pressure should be in the normal range. Such a worn engine can benefit from higher viscosity (thicker) oil such as 20W-50 in above freezing weather and 10W-40 in winter. That will increase idle pressure and the thicker oil film maintains a better film between the worn parts

Hi. This issue has several causes, but the oil light indicator is a strong sign of low pressure in the engine. This will cause the engine lubrication rate to drop, thus, producing a illuminated oil light, and erratic Oil pressure readings. The necessary actions are to have a manual oil pressure test ran on this engine, asap. When running a manual oil pressure test, you will discover if the true oil pressure is low, or normal. If the test proves that the oil pressure is, indeed, low, this will confirm that the Oil pump is suspect.

Now, if the true readings given during the manual oil pressure test are indicating that the pressure is normal, this will be the result of a failed sending unit(oil pressure switch). Although the oil pressure is suspect, this is not your only issue here. There seems to be a abnormal compression rate, present. This is causing the rough idle, and erratic RPMs. I recommend to administer a engine block compression test, as well. This test will discover if , indeed, there are issues within the cylinder heads, and block structure, such as a worn head gasket, cylinder wall issues, and cracked block. Normally, these issue will send signs, like white, or gray smoke out the tail pipe, or discolored oil. It will, also, promote erratic RPM ratings, and a rough idle. Have the oil pressure test, and engine block compression test ran, asap.

Once the test are administered, you will be able to isolate the actual problem areas, more accurately. Check the spark plug wire sets, and ignition assembly for faults, also.

When the engine and oil are cold it will show a high pressure because of the viscosity of the oil. When it warms up the oil is thinner. If it doesn't drop below 20-25 psi at warm idle I wouldn't worry about it as that is normal.

this is a common sign of a bad oil pressure sender, but could also be caused by low oil pressure, a sender is cheap,but it"s always smart to do a pressure test first with a mechanical gauge,you can obtain a mechanical gauge from most automotive parts stores. then you"ll have to locate and remove the oil pressure sender and install the gauge you bought. make your test at warm idle you should have at least 25 psi below that you may very possible have worn engine bearings making it impossible for the engine to have any better oil pressure at idle. if you have 25 or greater psi of pressure at idle replace your oil sender and you"ll be back on the road

first suspect is the pressure sending unit itself. BUT that condition can be serious and if replacing the sender does not correct the problem you need to have an external gauge attached and actual pressure verified. since you hear no noise (yet), I'd lean towards the pump pickup screen being partially obstructed. Across the board crank bearing wear is also suspect though.
Oil pressure always reads higher when cold because the oil tends to thin out a bit when warm. It should however never drop that low, 15psi is the absolute low idle pressure I accept as nearly normal on any engine.
Fuel contamination in the oil can also cause problems but is easily identified by a simple "sniff test" of the dipstick.

sounds like you have sludge build up in the engine. you should try a oil additive to help clean out some of that sludge on your next oil change

I have a 99 blazer and ever since I have owned it, it reads lower in pressure when idling, but will go up too 40 while driving. This is normal for the vehicle. If the pressure gets real low, and stays low, it means its time for an oil change.

As long as the pressure goes up when you give it gas, it is fine.

10 lds at idle when cold but after buildup of preasure. This will change with oil temp. r.p.m. and engine wear. Low oil preasure is usually the result of engine wear but not a fault in an engine. If the oil light fliker's at idle when warm then the engine is excessavely worn and will soon cause problem's if the oil light stays out when warm at idle then its nothing to worry about.