Oil Pressure Question

[EZ$]

OK, so I've had the car on the road for a bit, and the oil pressure has always run at around 45-55 lbs. I finished replacing the plug wires yesterday, so I thought I'd take the car out to make sure I hadn't screwed things up, and I noticed a jump in the oil pressure reading. It was running around 55-60 lbs. with some movement up to around 70 lbs. It just caught me off guard, and I was wondering if it's anything that I should be concerned with, or anything that I should check out.

Car ran great, so at least I didn't screw up the plug wires!

[egchewy79]

Is this with a manual gauge or reading on the dash? Are you using speed hut gauges and senders? I found them to be unreliable.

[EZ$]

Yeah, Speedhut gauges, but how many thousands of us are running similar gauges. I know that they're not going to be exact, but the variation just kind of threw me off, and I figured I'd check to see if it's something I needed to investigate.

[BUDFIVE]

EZ$, if the only change you made was plugs and wires, perhaps you bumped the oil pressure sending unit signal or ground wire/connection, changing its resistance up or down. I don’t know the Speedhut sending unit-the Autometer resistance decreases as pressure increases. I think I read you have a 331 (SBF)? My 347 SBF oil pressure sending unit is close enough to the #5 plug wire I can imagine bumping it. And the cluster of gauge wires passes right past the distributor and even share a ground with the distributor. Just a thought.

[egchewy79]

I had my original speed hut sender fail a couple of years ago. It was reading 40-50psi warm and one day I look down the my oil pressure was at 0.
I was pulling into my driveway at the time and turned around expecting to see a trail of oil behind me.
Speedhut sent out a new sender no questions asked. New sender has been reading around 60-70psi warm. I know it's likely not accurate and could check with a manual gauge, but at least it's not reading 0 anymore.
Bottom line is that these senders can fail or be inaccurate at times.

[cv2065]

Are you talking about cold or warm? Idle or cruise? What weight of oil are you running? Running 10W30 on my last car I ran about 60 cold and 35-40 warm. That of course fluctuated on acceleration, reaching 55-60 again at cruise. Sounds like you are fine if that’s what you are getting at a cold idle. Just about perfect. Different viscosity oils will also impact the pressure. I’ve never had any issues with my Speedhut gauges.

[EZ$]

Thanks guys. I'm pretty religious about checking my gauges. I literally can't afford any major failures. As a note, it was while cold, short cruise to check the operation with the new wires, and 5W30 oil. I'll just run it for a while and see if there are any changes. I will check the pressure sender connection to rule that out.

[johnnybgoode]

If you changed your filter to a less restrictive brand that could easily give you an additional 5lbs of pressure. Just a thought.

[narly1]

I'm of the thinking that the actual pressure value isn't important. Rather, any variance from its usual, normal working (aka baseline) value is. As with any change figuring out the cause be it from an external component swap / disturbance vs something going wrong internally with the engine itself is the challenge. You have to rule out the former before you can blame the latter. Work from the outside (easiest) in.

Earl