Stock Oil Pressure guage is worthless

[Ducman82]

so i added a Autometer Ultralite II OP guage this weekend. man... ..... all i can say is that people were right about the stock OP guage being worthless. when i nail the gas, i get 80-85 PSI. . stock guage... 45ish... then when i let off the fuel and coast to a stop, i get 20-25 psi... . stock op guage 40-45... all i have to say is GO MOPAR! on that dumb idea... ... ... . thats my rant for the day. #@$%!#@$%!

 

[BHolm]

The factory gauge is no more than a glorified idiot light. If there is any oil pressure it gives you a fake reading. How have I seen it put here... something like "what the consumer might expect to see" is how the gauge is designed to read. What a joke, a real gauge probably would have been cheaper too.

 

[Tinman]

I love it when I change the oil and crank it up. Right up to normal pressure, no delay or anything. Way to go Chrylser. I've had a Di-Pricol mechanical gauge on back order for about 6 months now. (I'm really tired of looking at the whole in my pillar pod. ) Worse thing about is that stupid stock gauge is dead space on the dash and I have to waste a gauge pod to get a real gauge. A while back, I ask here about a Smarty feature to make the stock gauge a real gauge, but someone responded that it would take hardware (sendor) changes as well as software. Still, I bet there would be market for a kit like that.

 

[KnightR]

The big reason they don't think oil pressure is like my wifes reasoning run till it stops. We are a small percentage who jump behind the wheel and really give a damn about oil pressure.

 

[Matt400]

I hear ya but in the event of pressure loss your oem design will sound a dong and illuminate the "check gauges" light. When / if that ever happens you can look at your aftermarket gauge to confirm you should have already been shutting down.

 

[seafish]

So guys, this leaves me wondering if the stock water temp guage is accurate or if it, too, is only a glorified idiot light. Anybody know?? Thanks

 

[Matt400]

From what I see it would be correct. The reason I believe this is because there is just the one sensor and that sensor reports to the Dash and ECM. If I plug in my scanner I can read actual engine temp in degrees and it agrees with the placement of the dash needle.



In the past I played with that circuit and found that if I fooled the ECM with resistors that drove my scanner readings to 220 the ECM would engage the vistronic fan.

 

[seafish]

Matt, thanks for the info. So I guess that means I really only :-laf need analog:



pyrometer, boost pressure, voltage meter, oil pressure and oil temp.



and of course a fuel pressure gauge mounted on the fuel filter!



I guess with my mostly stock 2005 with G56,

the transmission temp, rear diff, and rail pressure are mostly optional, right??

 

[KWilkinson]

Well here is how I see it... you guys are 100% correct in my mind about having the oil pressure gauge read accurately... however, a majority of the people on the road are acustomed to a gauge that reads around 40psi oil pressure. Pretty much every car, truck or suv of any make or model reads 40 lbs. If someone saw a gauge that under throttle would jump to 80psi, but at idle drop to 15-20, they would flip out and complain to the dealer swearing that there is something wrong. Not everybody knows the differences in high volume to constant pressure oil pumps and different galley and oil port designs, and dont care to understand them and why they are the way they are. Our engines do run fairly low oil pressure for the size of these pumps, but circulate the oil just as fast as it can return to the pan. Newer heavy trucks are the same way, they really run upwards of 120 psi oil pressure at higher rpms, but the gauge usually stays around 40. Our oil pressure senders are just a 7psi switch. If it has at least 7psi oil pressure, the PCM has the gauge "lie" based on engine rpm and coolant temp. Below 7, the gauge shows 0.

 

[Ducman82]

that is true, most people dont know what to look for when it comes to guages. they make sure there is no DING sound, nothing in red, or on empty.

 

[Matt400]

Matt, thanks for the info. So I guess that means I really only :-laf need analog:



pyrometer, boost pressure, voltage meter, oil pressure and oil temp.



and of course a fuel pressure gauge mounted on the fuel filter!



I guess with my mostly stock 2005 with G56,

the transmission temp, rear diff, and rail pressure are mostly optional, right??

Its all what you want and feel comfortable with. On my 03 I started off simple with an SRT A-pillar along with a single dual gauge-

• Transmission Temp
  
• EGT
  

Looked like this:

#ad


For an auto truck I think its all that is needed. Then I got a wild idea and went overboard, got pretty crazy and installed 6 gauges-

• EGT
  
• Boost
  
• Rail pressure
  
• Oil pressure
  
• Lift pump pressure
  
• Transmission Temp
  

Looked like this:

#ad




That was expensive so when I got my 05 I just couldn't swallow doing it all over again plus it just seemed wasteful so now have just 3-

• EGT
  
• Boost
  
• Transmission Temp
  

Now looks like this:

#ad




So coming around full circle if I had to do it again in another truck I would keep it simple & safe with just a single SPA like I did the first time. You get to set warning levels for the led's that flash at you + the SRT A-Pillar is a natural clean install.



I just don't see a need for all the other gauges however the Edge Insight is a pretty cool idea, wonder if they found a way to access the Auto Trans thermistor mounted in the pan?

#ad