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94 6.5 AC Delco ops is modified and new. This seems to happen after sitting. Hot or cold and stops once I drive it a bit and once cruising on the freeway for a bit it smooths out. Should I replace the gauge? Is this a bearing issue? Motor is low mileage under 50,000 and doesnt burn any oil. Thanks.

94 6.5 OP Gauge erratic OP Gauge:

 

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Mines a junk bwd one and it does the same thing except sits around 80psi.

Probably a grounding issue in your case/picking up alternator pulses?
 

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Discussion Starter #3
all my grounds are clean and new I do have an added ground from theintake to the firewall at the wiper motor. I was going to order a spare OPS should I try a new sensor first?
 

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Did you check/clean the ground wire that attaches to the ALDL (OBD1) socket?

I had a problem with my volt meter jumping around. Removed the cluster and gently bent the meter grounding tabs to make better contact with the circuit board. Solved my volt meter problem. Maybe the same thing is going on with your oil pressure gauge :confuzeld
 

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You could T-in a mechanical gauge or put it in the other threaded hole in the valley or head to confirm its an electrical problem. But I agree with everyone else that it appears electrical
 

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Which oil filter do you put in the truck?
 

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Discussion Starter #7
Did you check/clean the ground wire that attaches to the ALDL (OBD1) socket?

I had a problem with my volt meter jumping around. Removed the cluster and gently bent the meter grounding tabs to make better contact with the circuit board. Solved my volt meter problem. Maybe the same thing is going on with your oil pressure gauge :confuzeld
Ill do this in a bit. Easy enough to pull the cluster on these 94s
 

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Discussion Starter #8 (Edited)
Which oil filter do you put in the truck?
Some Bosch long life premium deal. I just changed the oil last night installed a wix filter and added Lucas heavy duty oil stabilizer and its still doing it. Have 2,000 miles on the motor since install.

You could T-in a mechanical gauge
I guess this will be my best option to really see if the pressure is jumping. This will come after I try another ACDelco ops since I need a spare anyway. Just ordered one. I will check the gauge ground in the cluster and wait for this ops to arrive.
 

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I had a problem with my volt meter jumping around. Removed the cluster and gently bent the meter grounding tabs to make better contact with the circuit board. Solved my volt meter problem. Maybe the same thing is going on with your oil pressure gauge :confuzeld
94 6.5 OP Gauge fixed:


It seems to be fixed now I drove it four times and all good. I used two small picks to get the tabs bent good into the circuit paper. I should have done my other gauges but was too busy dusting the areas behind my gauges and stereo while it was apart so got my ocd fix for the day:hehe: Thanks guys i appreciate the help:thumb: (Freddy I dont know how to embed the videos)

:clap::HiHi:
 

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Super Moderator Eco-Logistical
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ya might want to test the ops lift pump action, make sure you are getting lift pump function before confirming it's fixed!
 

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Discussion Starter #11 (Edited)
ya might want to test the ops lift pump action, make sure you are getting lift pump function before confirming it's fixed!
Copy! Also just drove the truck for 2 hours and no more jumping gauge. Thanks again guys.
 

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Discussion Starter #12
Just reporting back i drove the truck all morning with a steady gauge:clap: That was definitely my problem on the circuit paper. Thanks Freddyack for the tip you were right on:HiHi:
 
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My 6.5 scared a prius
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Well Damn it!!!! mine does the same thing!!!!!! that is awesome, i am goinna rip my dash out like a new kid with a hotwheels toy and check all the pins! :hehe: That damn thing had me as confused as a baby in a strip joint haha
 

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Hmm I wonder if this is a problem with the newer style gauges as well. The oil pressure gauge on my 96 just started doing the exact same thing. Went from working perfectly to twitching constantly in one day. I was about to buy an OPS but now I'll try this first before I spend the $$!
 

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Discussion Starter #16
Still Good:thankyou2:RockOn:
 

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Discussion Starter #17
Still Good:bounce:
 

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I also removed the cluster and bent the tabs using two small tools as per Freddyack's suggestion. Now it works fine.
 
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Another thing that happens over time is the silicone oil inside the air core motors dries up and stops dampening the motors movement. The 02 and older trucks use an air core motor which is basically a magnet riding inside a electro magnet controlled field. The amount of current going to it controls the magnetism applied, and moves the internal magnet that is attached to the shaft that moves the needle. Air core motors react VERY fast, so the factory used a silicone oil inside of them to dampen the movement of the motors. Over time this silicone oil dries up giving you a twitching gauge. This just started happening to my 95 with the fuel gauge, and oil pressure gauge, so I'm going to order some 30,000 weight RC diff fluid to put back into the air core motors to dampen the motors movement(I'm also planning on doing an ESCALADE cluster at teh same time to get the 120 MPH speedo, blue backlighting, and white pointers that light up orange). I can't take credit for this though as it is a sticky over at gmt-400 as its a common problem to these trucks.
 
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