Ping WARMAN

Hi Jim...
Brad from Calgary writing. It's been a while, but I have a question for you if I can.
I just purchased a 93 Cobra. Needless to say, I'm in love.
In addition to the usual Ford mods, the last owner put a C&L TB on it, K&N, fuel pressure indicator, headers, no cats, new exhaust.
But my question is, the oil pressure gauge moves. Always in the safe zone, but it moves. My last Mustang NEVER moved. At idle it drops, when you get the tach up, it rises. Car only has 40,000 miles on it but I have a feeling some of those were put on 1/4 mile at a time. It's a smokin' fast car.
I wonder if the sender if faulty. The oil is at the safe level. I was always told don't worry if the needle is in the safe zone, but I'm not sure what would make it move.
Can I please get your thoughts?
Thanks!
Brad
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The first thing that comes to mind, Brad, is that someone has changed the sending unit.... From somewhere in the late 80s on, the oil pressure "gauge" is more of an oil pressure "light". The older ones had a variable resistance that had the oil pressure gauge respond to any variations in oil pressure.... The later ones were simply a switch.... When oil pressure comes up, the switch closes and the needle goes to a predetermined spot on the dial...
To be on the safe side, you could check the oil pressure with a mechanical gauge... but in the absence of any rattling lifters and other scarey stuff, it doesn't sound like there is much cause for concern....
Top-postingly yours, Jim...

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
What makes it move it the changes that occur to oil pressure as the engine speed changes. Anywhere in the "Normal" ranges is between 25 and 60 PSI and thus normal.
One can always "T" in a pressure gauge, by inserting oe into the 1/8 pipe fitting tap in the block, before the sender unit
mike

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jim, Mike:
Thanks!
I never knew the gauge was an idiot light. Who woulda thunk? But in a Cobra I'm not surprised Ford used a real one or the past owner did. Very interesting.
Thanks again!
Brad

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Got a 93 Bronco with a 351W that fluctuates a good bit. It's fine as long as you don't get down near 10psi at idle. You should run around 30psi at highway speeds. Though if it fluctuates a little too wildly you should check to see that the sender is okay. If there's oil leaking around it then you need to replace it because not only does it make your gauge not reliable but it can leak something fierce when it finally does go and make you think you need a new rear main when you don't!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Gotcha and thank you. No oil leaks as far as I know. I will keep an eye on it nonetheless.
Brad
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.