92 Accord Ex (Automatic)...Oil Light... Engine Reving up and down when in neutral and park...

My 92 Accord EX's oil light comes on add odd times. It will only come on
after driving for a little while, and it will only come on when i am
completely stopped. Sometimes it will flicker on, then when i start going
again it will turn off, and other times it will stay on for the rest of my
trip, what could it be? Also just recently my engine started reving up and
down from 1000 to 2000 rpms when it's in neutral and park... sometimes it
revs up higher when the engine is cold... some have suggested that it's
the idle air controller causing the problem, could it be something else?

 

Hi

I am assuming you are not losing oil and everything is normal? No knocking
sounds?

Usually you can determine if the problem is within your sensor or real by
disconnecting the oil sending unit. (for instance, it could be that you have
a bad connection on that sender). If disconnected, the oil light should not
be on. If nothing changes, the problem is within your instrument cluster or
the wiring from your sensor to the cluster.
If it goes off and stays off, replace your oil sending unit to see if that
fixes your problem -- they are pretty cheap. Most likely that is what a
mechanic would do first.

Hope this helps.
Remco

 

As I was reading your message some more, was thinking that your problem
with the engine speed might be unrelated to the oil light. Unless the
engine speed is really low or really high, I don't think it has much to
do with your oil pressure.
1-3K RPM shouldn't cause a low oil pressure, unless your oil pump is
bad -- let's hope that isn' t it as that will be more expensive.

First figure out if your oil light is telling you the truth. I wouldn't
drive the car until you can acertain that because if you have a
legitimate oil problem, you can do damage to the engine.
The easiest way to do that is described in my first message. Oil
sending units do go bad after a while.

Just wanted to clarify that, as I don't want to steer you in a bad
direction. Also wanted to make sure you don't damage your engine,
thinking you can ignore the problem.

Regards
Remco

 

What you are seeing is typical of low oil pressure. As you rev the
engine, the oil pump turns faster and builds more pressure, thus the
light turns off. Also, the warmer the engine, the more easily the oil
flows, and the pressure drops. Low oil pressure can be very damaging to
the engine, and you should have it looked at right away. The first thing
to do is to hook up an oil pressure gauge to see if the oil pressure is
up to par (as it is possible that the problem is with the oil pressure
sender, not a problem with the oil pressure). There can be many causes
of low oil pressure. Common ones are worn oil pump and clogged intake to
the oil pump.

Yes. Vacuum leaks can cause those symptoms as can air pockets in the
cooling system.

Just for fun, see if there is any yellow, foamy substance under the oil
filler cap or on the dip stick. Hopefully the two symptoms you describe
are unrelated, but if you have a bad head gasket there could be coolant
making its way into the oil. Oil and coolant will then get whipped into
a foamy substance, and you can get oil pressure problems. The
disappearing coolant can cause air pockets in the cooling system,
leading to the engine revving up and down at idle.

 

'

have you... checked the OIL level? its a pressure sensor, so when its
flickering, you arent getting any pressure. low oil level, blocked pump
screen, or a marginal pump are some reasons. id start saving for a new
engine, or new car.