oil pressure sender failures: Continued

Executive summary:

1995 SW1 has gone through about 5 oil pressure senders. They all started
leaking through the electrical connection. The first 4 were from NAPA, then
I bought the factory one from a Saturn dealer. That one lasted
maybe 500 miles. Car has 194,000 miles. Regular oil changes with Castrol
GTX.

Okay, this points to high oil pressure. Before tearing off the timing cover
and replacing the oil pressure relief valve, I wanted to have a metric to
compare. I bought a SunPro electric oil pressure gauge. Installed it
today. Gauge has calibrations from 0 to 100, with 50 being dead center. I
would have bet that my pressure was going to
be around 85.

Good thing I did not bet! Pressure hovers around 50. I saw it jump almost
to 60ish with the throttle open, but that's it. It drops to around 35 or so
when the engine is hot and idling, which I would expect of a car with this
many miles.

Is anyone else running with an oil pressure gauge, and if so, what are the
pressures that you see? I have a hard time believing that 50 is too high.

-David

 

I have two Saturns with oil pressure gauges. Highest I've seen has been
around 60, lowest around 15 to 20 at idle. Your pressure seems normal.

Lane [ lane (at) evilplastic.com ]

 

Have you been careful with respect to the torque applied on the senders when
installing them? Those sending units are not that stout, and it's easy to
overtighten them ....

 

I've been careful, tight plus 1/4 turn. The leakage comes from the top of
the sensor, not from the base.

-David

 

I just got back from a 40 trip and those are exactly the ranges I saw.

I guess if the sender unit from the gauge holds up, my problem will be
solved.

(Gee, I wonder if I should report these repeated failures to MrFact? (a
joke,a joke.....))

-David

 

50 is not too high. And even if it were 150, the senders are not failing
due to pressure. They're just cheap pieces of junk. If the last one only
lasted 500 miles, then it should surely be under the 90 day warranty. Keep
screwing them in there.

 

THAT's a very good point. And they don't have to be very tight to seal up
on the threads. MOST people overtighten MOST things that are screwed
together.

 

I have had most of the failed sensors replaced under the 1 year warranty
from NAPA. And my thought had been the same as yours, I would just change
it everytime I changed the oil. But with a 500 mile failure that plan goes
out the window.

If the problem was just that these are pieces of junk, wouldn't everyone be
seeing the problem?

-David

 

Good point. So what are you doing that other people aren't?

 

That is where the weirdness comes in. There ain't too much to screw up
here. I'm kinda hoping that I might see a situation where the pressure goes
high, but that has not happened in the 50 miles that I have driven the car
since I put in the gauge.

-David