when im driving my truck the oil pressure is normal but when i stop at a red light my pressure drops dramaticly and im getting a vibration in my motor any clues why ?? thanks
2006-08-11 09:24:35 · 8 answers · asked by BICCA 3 in Cars & Transportation ➔ Maintenance & Repairs
When the vehicle is cold the pressure it high correct? After you run it the oil gets hot and thins some everything in the engine expands some, clearances can be more hot than when cold.. The bearings produce the oil pressure. The pump is designed to provide a volume of oil that is carried thought the engine through oil galley's. When the oil reaches a restriction like to bearing surfaces it slows the flow and causes back pressure on the incoming oil to the bearings. This causes the oil pressure to be higher. At an idle it only pumps the volume it can. When the RPM's are increased so is the volume of oil being pumped, thus you see the oil pressure increase on the guage. Have a manual guage screwed into the pressure port and check the cold, hot and road oil pressure. Now compare those readings to the specifications in the manual and make repairs accordingly. Every thing on that end may be fine and you can have a faulty guage. The vibration could be the harmonic balance or dampener has slipped and now it is out of balance some. A bent or missing fan blade can cause vibration. Missing weight on the flywheel can also cause that. I just don't recall a vibration from low oil pressure unless there is not enough to keep the lifters pumped up and you are experiencing a miss. Check the oil level to make sure it is full. Let us know what you come up with.
2006-08-11 10:23:50 · answer #1 · answered by Can do it man 3 · 1⤊ 0⤋
Well, it's normal for oil pressure to drop a bit at a stoplight, but it sounds a like it's falling a little too much. Usually the cause is worn bearings - the surfaces of the bearings are further apart, so the oil pump has to push more oil through them, bringing down the pressure. You can try running thicker oil; that often helps a little. If not, it's time for new bearings.
2006-08-11 16:32:17 · answer #2 · answered by Mad Scientist Matt 5 · 0⤊ 0⤋
Sounds like a problem when idling. Could just need a tune up.
Oil pressure is dropping because it's controlled by the speed of the motor, if the car is idling too slow you will not get enough oil pressure. When you hit the gas it gets better because the engine is now going faster.
Again probably just needs a tune up but possible idle adjustment too.
2006-08-11 16:31:42 · answer #3 · answered by John 6 · 1⤊ 0⤋
Before you jump to any conclusions, have your engine oil pressure measured with a professional shop technician's oil pressure gage. The engine should be hot and idling. The oil pressure should be at least 15 psi.
2006-08-11 16:42:12 · answer #4 · answered by bobweb 7 · 0⤊ 0⤋
Probably the oil pump getting ready to fail. The vibration could be a sign of impending damage or damage that has already occurred. You need to get this vehicle off the road at once before you have a catastrophic engine failure.
2006-08-11 16:30:56 · answer #5 · answered by Anonymous · 0⤊ 1⤋
Does your oil need to be changed or does it have the right grade in it? Your idle could be set to low. Last thing is your oil pump could be going bad, but I put my money on the first three items.
2006-08-11 16:32:02 · answer #6 · answered by David 3 · 0⤊ 0⤋
yeah but your not going to like my answer, your losing oil pressure and then the lifters cant pump up properly and then it runs horrible. buess what your going to need to do. rebuild or replace
2006-08-11 16:32:09 · answer #7 · answered by Christian 7 · 0⤊ 1⤋
make sure it has enough oil in it before you take it apart
2006-08-11 17:04:42 · answer #8 · answered by sd_southbound 1 · 0⤊ 0⤋