* Oil Pump: While a failing oil pump is a possibility, it's less likely to be the *only* problem causing the pressure to increase with engine speed. A failing pump would generally show low pressure at all engine speeds. However, a worn pump *could* contribute to the issue, especially if it's already weak.
* Oil Pump Pickup Tube: This tube draws oil from the bottom of the oil pan to the pump. If it's clogged, kinked, or otherwise restricted, the pump won't get enough oil, resulting in lower pressure, especially at idle when oil isn't being splashed around as much. This is a common cause of pressure dropping at idle.
* Oil Pan: Similar to the pickup tube, a severely clogged oil pan can restrict oil flow. Sludge buildup or excessive debris can limit the oil pump's ability to draw sufficient oil.
* Worn Engine Bearings: Low oil pressure at idle, coupled with higher pressure at higher RPMs, often indicates worn bearings in the engine. At higher speeds, the oil pressure is increased due to the higher engine speed, temporarily masking the problem. Worn bearings are a serious issue that needs immediate attention.
* Oil Pressure Sensor: Although less likely to be the *cause* of low pressure, a faulty oil pressure sensor could give an inaccurate reading. This should be checked but doesn't explain the pressure increase with speed.
* Oil Viscosity/Level: Make sure you're using the correct weight oil (check your owner's manual) and that the oil level is at the "full" mark on the dipstick. Using the wrong weight oil or having low oil can dramatically impact pressure.
What to do:
1. Check the oil level and condition: Is the oil level low? Does the oil look dark, sludge-like, or contain metallic particles?
2. Check the oil pressure sensor (and gauge): A faulty sensor can give a false low reading. Sometimes a professional mechanic can use a mechanical gauge for a more accurate reading.
3. Listen for unusual engine noises: Knocking, ticking, or other abnormal sounds could indicate worn bearings.
4. Consult a mechanic: This is crucial. The description you've provided suggests a problem that requires professional diagnosis. A mechanic can perform a pressure test, inspect the oil pump and pickup tube, and assess the overall engine condition to determine the root cause. Ignoring low oil pressure can lead to catastrophic engine damage.
Don't drive the van extensively with low oil pressure. The risk of engine damage is significant.
