90 Corolla Oil Pressure Switch

We've had the oil light come on, while driving, and stay on, untill the
revs go over 3000RPM. To try and fix this problem, dad has changed the
oil pump, and still the same problem. So now he's changing the Pressure
switch, and comes to find out that the one off of his 90 Corolla wagon,
same engine family, same year same everything, except his was made in June
and it is an Automatic. The one that has the problem was made during July,
and is a standard. is different. They both fit, and the one that we know
works, turns the light off, but the one that we think is broken, turns it
on. They're different in size, and the diameter of the hole. one is a
pin sized one, and the other is about 2 times bigger!! Will they both
work??

Please let me know!!

CRC

"72Capri" <corolla1990@hotmail.com> wrote in message
news:5240647a70f5a804238082ff7708bbaa@localhost.talkaboutautos.com...[color=blue]
> We've had the oil light come on, while driving, and stay on, untill the
> revs go over 3000RPM. To try and fix this problem, dad has changed the
> oil pump, and still the same problem. So now he's changing the Pressure
> switch, and comes to find out that the one off of his 90 Corolla wagon,
> same engine family, same year same everything, except his was made in June
> and it is an Automatic. The one that has the problem was made during
> July,
> and is a standard. is different. They both fit, and the one that we know
> works, turns the light off, but the one that we think is broken, turns it
> on. They're different in size, and the diameter of the hole. one is a
> pin sized one, and the other is about 2 times bigger!! Will they both
> work??
>
> Please let me know!!
>
> CRC
>[/color]

Your dad should borrow or rent an oil pressure gauge, hook it up to the port
for the oil sender, and measure oil pressure at idle and at higher RPM. If
the oil pressure is within specifications, then you know you have a problem
with the sender, warning light, or wiring in-between.

If oil pressure is too low and you know that the replacement oil pump is
good because you used a feeler gauge to measure crescent-to-body clearances,
then there is an internal problem in the engine like blockage somewhere,
clogged oil pickup, or excessive clearance in the crankshaft bearings.

Unplug the wire connector from the oil sender and with an ohm meter or
continuity tester, check for continuity between the terminal on top of the
sender and the sender body. With the engine stopped, there should be
continuity and with the engine running, the circuit should be open (no
continuity). If this is not the case, the sender is bad. Rather than using
a 17 year old replacement part, my recommendation is to use a new oil
pressure sender after checking.
--

Ray O
(correct punctuation to reply)

So the pump has been changed, and there was no difference,(now before
people get worried that we're going to ruin the engine, there was no
change in engine sound, temperature, fuel consumption, everything was the
same. So the switch had to of been faulty) but my parents took the car on
a 4 hour hockey trip with my brother, and it did the trick!! The light is
out, and hasn't been on since. Thanks for looking. :D

CRC