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Fluctuating oil pressure
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D Lymett
Sep 7, 1999, 3:00:00 AM9/7/99
to
I have a 91 convertible, no mods. Recently the oil pressure gauge dropped
to zero. While watching it slowly made its way back up to 30. I stopped
the car. turned off the engine checked the oil level. Oil level was good.
Restarted the engine, oil pressure moved up near 60. Now most of the time I
start the engine the oil pressure goes to 60, but sometimes stays at zero.
Also while driving the oil pressure will drop and rarely go above 30.
Everything sounds, feels and looks fine, except for oil pressure gauge
reading. Now I've changed the oil pressure regulator, oil pressure control
valve, oil pick up tube, and oil pump. No change, same sysmtoms.
to zero. While watching it slowly made its way back up to 30. I stopped
the car. turned off the engine checked the oil level. Oil level was good.
Restarted the engine, oil pressure moved up near 60. Now most of the time I
start the engine the oil pressure goes to 60, but sometimes stays at zero.
Also while driving the oil pressure will drop and rarely go above 30.
Everything sounds, feels and looks fine, except for oil pressure gauge
reading. Now I've changed the oil pressure regulator, oil pressure control
valve, oil pick up tube, and oil pump. No change, same sysmtoms.
Jack
Chris
Sep 7, 1999, 3:00:00 AM9/7/99
to
Have you changed your oil pressure gauge???? I've had trouble with almost
every gauge in my car over the years...
every gauge in my car over the years...
Chris
D Lymett wrote in message ...
Dictores
Sep 8, 1999, 3:00:00 AM9/8/99
to
My 1989 Convertible displays the same symptom. Recently replaced the sending
unit. When I start the engine, pressure is about 50 psi. While cruising the
highway....it will drop to about 20 psi.....idle sometimes at 10 psi.
unit. When I start the engine, pressure is about 50 psi. While cruising the
highway....it will drop to about 20 psi.....idle sometimes at 10 psi.
D Lymett
Sep 9, 1999, 3:00:00 AM9/9/99
to
Well I took a look at my gauge, found no problems. But when I looked at my
sending unit, it was dirty. So I disconnected the unit cleaned the
connector area and then clenaned and tighten the connector. Now my gauge
works fine. But I already changed the several components as listed at the
beginning of this thread.
sending unit, it was dirty. So I disconnected the unit cleaned the
connector area and then clenaned and tighten the connector. Now my gauge
works fine. But I already changed the several components as listed at the
beginning of this thread.
Dictores wrote in message <19990908105244...@ng-fv1.aol.com>...
VTiscareno
Sep 9, 1999, 3:00:00 AM9/9/99
to
My 89 conv does the same thing. Right now, it is working well- 55 to 60 lb at
cruise, 25 to 30 at idle.
Sometimes it will drop to zero! But it can't be there or the engine would have
seized. It has to be an intermittant connection at the send unit or along in
the wiring. I thought that the sending unit may be the problem, but after your
explanation of replacing the unit with the same results, then something else is
going on with the circuit.
Victor
PS. The low fuel light has never worked on thsi car.
cruise, 25 to 30 at idle.
Sometimes it will drop to zero! But it can't be there or the engine would have
seized. It has to be an intermittant connection at the send unit or along in
the wiring. I thought that the sending unit may be the problem, but after your
explanation of replacing the unit with the same results, then something else is
going on with the circuit.
Victor
PS. The low fuel light has never worked on thsi car.
D Lymett
Sep 9, 1999, 3:00:00 AM9/9/99
to
Try tightening the connector to the sending unit. Mine was very loose.
Because of that dirt, grime and oil (from when the oil filter was changed)
that got between the connector and the sending unit. Because the vibration
the connector would sometimes have a good connection and others not times so
good. My 89 conv has 120k on it. I have changed the oil pump, pressure
regulator, pressure control valve, and pick up tube, I still had fluctuating
pressure reading until I cleaned and tighten the connector to the sending
unit. Since then very good pressure. I only wish I spent the few extra
dollars($90 vs $23) for the adjustable pressure regulator.
Because of that dirt, grime and oil (from when the oil filter was changed)
that got between the connector and the sending unit. Because the vibration
the connector would sometimes have a good connection and others not times so
good. My 89 conv has 120k on it. I have changed the oil pump, pressure
regulator, pressure control valve, and pick up tube, I still had fluctuating
pressure reading until I cleaned and tighten the connector to the sending
unit. Since then very good pressure. I only wish I spent the few extra
dollars($90 vs $23) for the adjustable pressure regulator.
Chris Martin
Sep 13, 1999, 3:00:00 AM9/13/99
to
My gauge hasn't worked in 6 months (and come to think of it, neither
has my low fuel light), but I just chalked that up to a cold solder
point in the idiot light box, or somewhere else.
-Chris Martin
PAUL BIGORNIA
Sep 13, 1999, 3:00:00 AM9/13/99
to
After checking the oil pressure sensor (almost directly under the oil
filter) you might check for leaks. The oil cooler, the lines to and from
the cooler (check underneath the ac bracket) and the front of the
eccentric shaft. Mazda uses a "thermo pellet" in the front of the shaft
to control the oil cooling jets in the shaft when the engine is cold.
It's been known to cause oil pressure fluctuations at low RPM. One other
possible point of leakage is between rotor housings and side plates.
check on the spark plug side of the engine where it says "mazda" by the
oil filler tube.
filter) you might check for leaks. The oil cooler, the lines to and from
the cooler (check underneath the ac bracket) and the front of the
eccentric shaft. Mazda uses a "thermo pellet" in the front of the shaft
to control the oil cooling jets in the shaft when the engine is cold.
It's been known to cause oil pressure fluctuations at low RPM. One other
possible point of leakage is between rotor housings and side plates.
check on the spark plug side of the engine where it says "mazda" by the
oil filler tube.
Paul
D Lymett
Sep 16, 1999, 3:00:00 AM9/16/99
to
One reason why I changed all the Items (the oil cooler lines, oil pressure
regulator, oil pressure control valve, oil pick up tube, and oil pump) was
that I had noticed a lot of tiny air bubbles in my oil. I had just changed
my oil, when I pulled the stick out to determine the oil level when i
noticed the tiny bubbles. The last time I had seen air bubbles in engine
oil was in another car that had a very worn oil pump and had loud valve
clatter. So I changed the possible items that may allow air into the oil.
Now my oil pressure is 30 PSI at idle (750 RPM) and stays above 60 PSI above
3000RPM. Oh one other note, no bubbles in my oil. The most likely problem
was a worn oil pump, but I noticed that the new pickup tube base was twice
as thick and welded to the tube vice sealed.
regulator, oil pressure control valve, oil pick up tube, and oil pump) was
that I had noticed a lot of tiny air bubbles in my oil. I had just changed
my oil, when I pulled the stick out to determine the oil level when i
noticed the tiny bubbles. The last time I had seen air bubbles in engine
oil was in another car that had a very worn oil pump and had loud valve
clatter. So I changed the possible items that may allow air into the oil.
Now my oil pressure is 30 PSI at idle (750 RPM) and stays above 60 PSI above
3000RPM. Oh one other note, no bubbles in my oil. The most likely problem
was a worn oil pump, but I noticed that the new pickup tube base was twice
as thick and welded to the tube vice sealed.
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