What are the side effect of a bad oil pump in a car?

Question

After like 20 minutes or so, I notice my oild gage lowering toward the 25% level, if I raise the car's RPM the gage go back to the middle,, is it the oil pump, or what?

Oh, and the oil level is perfect, a bit above the 50% recomended level :-)

Answer 1

Actually it sounds a bit worse than the oil pump.

Oil pumps are pretty stable devices and rarely 'wear out' before something else goes. The symptoms you are experiencing sound to me like a problem with the rod and crank bearings. Here's why....

These bearing I am talking about is like the 'ball bearings' you are probably familiar with. These bearings are essentially slim pieces of metal with a goove in them for oil to move through and sit between the non moving parts of the engine block and crank and between the piston rods and the crank. The oil flows through the crank shaft into the bearings and out the rods to keep all these very fast moving parts lubricated.

Here's I feel has happened. THese bearing have become worn and oil it leaking out instead of flowing through the system and thus reducing the oil pressure. The reason you are seeing a higher oil pressure when you first start is due to the fact that when oil is cold is thicker and thus doesn't leak as bad. When the engine heats up, the oil become thinner and leaks more and thus reduces the pressure shown on your gage. When you 'rev up' your engine you are simply making the oil pump mush a higher volume of oil and thus it is compensating for the lost oil through the leaks. Since all this is happening internally to the engine your not going to see any oil 'leaking' out.

So... what to do to fix... well.. the permenant fix is an engine rebuild or at least replacement of the bearings. If your car is built in a manner that allows you to drop the oil pan with out removing the engine, this can sometimes be done in the car. However, 95% of the time, the engine has to be pulled out to replace them. This is very expensive unless you do it yourself.

There are a few temporary fixes.
1. Engine Restore - this is available at most auto parts stores and is an oil additive that has small particles designed to 'fill in' the gaps where the oil is leaking. I've seen this work wonders and I've seen it hasten the demise of the motor. 80% of the time it works as designed.
2. Higher viscosity - Engine oil is sold by it's viscosity which is essentially how thick it is. The two numbers you see on the oil 5-30wt, is the difference in viscosity from hot oil to cold oil. Using a higher viscosity (40wt) or using an oil additive designed to raise the viscoity of the heated oil will improve oil pressure and extend the life of your engine.

Remember, both of the two temporary fixes is only exenting the life of a dying engine. I suggest you find one of these solutions that works the best to keep the oil pressure up and then sell that baby before it dies on ya.

Or... pull the motor and do a rebuild.

Good luck and I hope this helps!

Answer 2

Migh try changing the oil and filter.
An older car will do this as it is worn and the oil flows more free at lower RPM's this is not always a bad oil pump. the oil passing through bearings and parts in the engine make the pressure. If they are worn then the oil flows.
If while you are under load the pressure is OK then It is not your pump.....
OH ya my mechanic looking over my shoulder said it could be your pressure relief valve in the pump is weak allowing the pump to bypass some oil....I'll buy him a coke in a minute...So you may be correct after all..it may be your Pump as the relief valve is built into it.

Answer 3

this is normal dont wory about it
on a vw rabbit it goes down to 10 lbs at idle
the hotter an engine gets the more you will notice it thats why they do the 10 w 30 oil thing is to get tho oil to thicken up a little when warm
as engine is reved up the flow of oil is higher it doesnt need that high of presser at idle as there isnt a load on your car dont waist your money getting it checked
if you know someone with a didigital or manuel gauge on a newer car check it out it does the same thing
thease "proes" here just like to sell you work

Answer 4

Check your oil level, (if your blonde thats the little cap with 710 backwords on it, or the circular pull tab). The mosts serious side effect is a blown engine, good oil pressure is critical to keep your engine running. Have a mechanic check the oil pressure on a seperate gauge if the the oil level is normal and the pressure is still low.
If this condition exists, DO NOT RUN THE ENGINE UNTIL YOU HAVE IT CHECKED.

Answer 5

a gas engine needs about 10 pounds of oil pressure for every 1,000 rpm of engine speed. if the engine in your car has alot of miles on it the gauge will move alot with engine speed. you could install a manuel oil pressure gauge to get a good PSI reading. if it reads low it could be anything from dirty oil,worn rod or main bearings or oil pump. they only way to tell that is by inspecting each item.

Answer 6

get it checked at a reputable repair shop. When an oil pump fails it stops delivering oil to the bearings and the engine will seize requiring a new engine. Depending on the motor it could run you anywhere from $2000. or more to replace.

Answer 7

It could be many things causing this condition. Have oil and filter changed (using manuf recommendations) and recheck after. If it continues, take car to certified mechanic--make sure by reading owners manual that this condition is abnormal. If it worsens, know that this is very detrimental to engine and may be very expensive if left unchecked.

Answer 8

a seized engine