Oil Pressure

[TexasViper35]

I’m seeing something new that is bothering me. The oil pressure at start up flies to 100psi and wants to stay around that. After the temp is warmed up it falls to 75-80psi at idle, but as soon as I start driving it goes back to 100psi. the oil and filter were changed about 1500-2000 miles ago, Viper filter and Mobile One; that was only 2-3 months ago. It’s done this yesterday and today, I’m wondering if I should be worried enough to change the oil and filter again, or just drive it a bit more. Thoughts (that won’t scare the **** out of me)?

 

[Steve-Indy]

Document the oil pressure with a mechanical gauge. Sensors go bad...change as necessary. Whether or not you change sensor...you could easily change oil and filter. If the filter you used was not the Viper specific filter for your car (presuming it is a Gen III...part number. 05037836AB...NEVER use the first version 05037836OAA) I would definitely change the filter. Our 03 pegs at 80 (top of the 03 gauge) on startup, then settles down to around 45-50 psi when fully warm, on a warm day, using Mobil 1's 0W-40.

 

[cothrelo]

My 05 with a paxton starts off in the 80-90 range and once warmed up goes down to the 50ish range. Driving it will go back to the 70-80's. The sensor is not hard to get to. I was looking at mine because the temps were all over the place and at one point looked to be over heating. Come to find out the plug on the sensor had worked its way out on the plug and basically had a loose connection. reseated the plug and has been fine ever since. I do have a spare sensor just in case. The sensor OEM was about $80 if I remember correctly

 

[MoparMap]

I've had my sensor go bad once in a really easy to spot way. When it failed it would show 25 psi with the key on and the engine not even running and carried that offset all the time, which gave me numbers very similar to what you are seeing. Yours might not be that extreme, but you could see if it shows anything noticeably more than 0 with the key on and engine off.

 

[SuperBird4404BBL]

The sensors are notorious for failing.

 

[TexasViper35]

I've had my sensor go bad once in a really easy to spot way. When it failed it would show 25 psi with the key on and the engine not even running and carried that offset all the time, which gave me numbers very similar to what you are seeing. Yours might not be that extreme, but you could see if it shows anything noticeably more than 0 with the key on and engine off.

Key on engine off it jumps to 50psi. Where is the sensor located?

 

[cothrelo]

passenger front of the engine mid ways down almost right in front of the header on a 05

 

[MoparMap]

Yeah, behind the bottom of the alternator. Not the easiest thing to get to, but shouldn't have to take anything apart. You will need a big socket for it though. I don't believe it was the typical rounded corner oil pressure socket style, but you will still need a deep set one to clear the connector body. I'd be careful when you remove the connector as well. On mine the locking block that holds the terminals in got stuck in the sensor. Easy enough to pop out with some pliers, but just good practice to check everything before putting the new one in.

 

[Chris L]

TexasViper35 - came across this thread from last year. I am experiencing similar issue with my 05 SRT10. As soon as I turn on the key before starting the engine the oil pressure reads at 50PSI then is nearly always pegged at 100PSI when driving. Were you able to change the sensor and did that resolve the problem? Thanks.

 

[TexasViper35]

TexasViper35 - came across this thread from last year. I am experiencing similar issue with my 05 SRT10. As soon as I turn on the key before starting the engine the oil pressure reads at 50PSI then is nearly always pegged at 100PSI when driving. Were you able to change the sensor and did that resolve the problem? Thanks.

No, I didn’t replace the sensor. The issue completely resolved after I cleaned the K&N Air Filters; that may be a coincidence! But the filter was very dirty after a road trip that included desert highways with a dust storm through one state. So look at your air filters as a start.

 

[Chris L]

Thanks for the quick response. Will check the air filters.
-Chris L

 

[ViCa_2k]

Thanks for the quick response. Will check the air filters.
-Chris L

Hey man. Currently having the same pressure reading issue your were having (key on engine off pressure shows 50, then engine on pegs to 100). Wanted to ask if you were able to fix it and figure out the cause? My mechanic believes I’m having a wiring harness issue but I just don’t know for sure. Thanks.

 

[Goggles Pizano]

Hey man. Currently having the same pressure reading issue your were having (key on engine off pressure shows 50, then engine on pegs to 100). Wanted to ask if you were able to fix it and figure out the cause? My mechanic believes I’m having a wiring harness issue but I just don’t know for sure. Thanks.

Saw your post on the alley.

Per the 05 service manual, only 1 sensor. It shares the ground and 5V supply with the cam sensor.

 

[Goggles Pizano]

Plus any codes come up.

 

[ViCa_2k]

You must be registered for see images attach

Yea I found this pic in the ‘05 manual and it only shows one. However the layout on the ‘04 looks different. I looked in my engine bay and it looks like the sensors go straight into the block as opposed to on the angle shown above. My mechanic says there’s a separate low oil switch but a few folks online have told me there’s just one sensor and no separate switch. Was there a block revision for ‘05 possibly? Lastly, I don’t have any codes as my CEL isn’t on.

 

[ViCa_2k]

Here’s a pic of mine for reference. If you rotate pic 180 deg it will make more sense. That screw and nut is for the tensioner pulley.

You must be registered for see images attach

 

[Old School]

I believe the oil sensors adapter is a 1 year only item, 2003. After that they went straight into the block. Service manual wasn't updated.

 

[ViCa_2k]

oh alright thanks, good to know. Did you happen to have any issues with your pressure readings? Trying to figure out why mine is acting up.

 

[Goggles Pizano]

If your mechanic doesn't know how to check/test a simple sensor/wiring, you better find a different mechanic.

First step is to pull on/juggle the harness and see what happens.
Second is unplug the sensor and see what happens.
Second measure resistance of sensor signal to ground pins and 5V reference to ground.
Third is measure ground continuity, 5V reference and signal pins to at the sensor harness.
Fourth test the ground continuity to an easily accessible sensor.
Fifth continuity for all 3 pins straight at PCM connector.
Sixth (you could do it early then above) jumper signal pin to with resistors or back probe, etc.

If he has a scan tool that can read the sensor voltage than there is jumper wire/voltage test like test six.

 

[Old School]

oh alright thanks, good to know. Did you happen to have any issues with your pressure readings? Trying to figure out why mine is acting up.

Mine was indicating 70 psi while running at every RPM and temp. New sensor took care of it.

 

[ViCa_2k]

If your mechanic doesn't know how to check/test a simple sensor/wiring, you better find a different mechanic.

First step is to pull on/juggle the harness and see what happens.
Second is unplug the sensor and see what happens.
Second measure resistance of sensor signal to ground pins and 5V reference to ground.
Third is measure ground continuity, 5V reference and signal pins to at the sensor harness.
Fourth test the ground continuity to an easily accessible sensor.
Fifth continuity for all 3 pins straight at PCM connector.
Sixth (you could do it early then above) jumper signal pin to with resistors or back probe, etc.

If he has a scan tool that can read the sensor voltage than there is jumper wire/voltage test like test six.

I should’ve mentioned my mechanic did electrical tests but it was a little while back and I don’t recall everything he did exactly. He mentioned the potential wiring harness issue after he had done his tests. There is a decent amount of wrapping/insulation on the wires though and I just believe it would be pretty difficult for something to get ripped off enough to cause electrical noise to mess with the signal. I will look into the steps you have sent so thanks for that.

 

[Badsnek]

A lot of wild info in this thread….a bunch that I wouldn’t follow.

I don’t think it was mentioned but 03’s have different oil pressure gauges and the numbers are different and consequently it’ll show different numbers than if that car had the 04-10 oil pressure gauge.

Also different things were done to the engines in 05-06 as far as bearings/oiling. So you’ll have 03/04 hot idle at 50 psi and 05/06 hot idle at 25 psi. 08-10 they changed things again and they’ll be at 50 psi for hot idle.

With that being said Dick Winkles who is Viper Engine Engineer has publicly said numerous times to not run 0W in these engines. That Dodge did it as an MPG/EPA move and that 0W will cause excessive wear. I actually have a screen shot of Dick’s personal recommendations.

 

[Viper Specialty]

I miss the days where old threads and posts for questions I had answered 379 times were easily found and referenced.

 

[MoparMap]

I don’t think it was mentioned but 03’s have different oil pressure gauges and the numbers are different and consequently it’ll show different numbers than if that car had the 04-10 oil pressure gauge.

I don't think that's necessarily true. The needle will be in a different place between the gauges, but the numbers are the same. 50 psi is 50 psi between the gauges, one just has 50 in the middle and the other has it to the side of middle.

Now if the sender resistances are actually different between them, then that would definitely cause an issue crossing them. I know there are differences between the early and later blocks because of the move from a separate sensor and switch to a single sensor, but I would think they kept the same resistance values between the sensor portion. They just rescaled the gauge so that "nominal" was straight up and matched other gauges.

 

[Viper Specialty]

What he said. Same numbers, different positions.

 

[Badsnek]

I don't think that's necessarily true. The needle will be in a different place between the gauges, but the numbers are the same. 50 psi is 50 psi between the gauges, one just has 50 in the middle and the other has it to the side of middle.

Now if the sender resistances are actually different between them, then that would definitely cause an issue crossing them. I know there are differences between the early and later blocks because of the move from a separate sensor and switch to a single sensor, but I would think they kept the same resistance values between the sensor portion. They just rescaled the gauge so that "nominal" was straight up and matched other gauges.

I had accidentally swapped an 03 gauge with different numbers into my 09 and I recall it reading different numbers which is how I caught it. My memory also ***** so I could be dreaming it up. But going off of memory

 

[Viper Specialty]

I had accidentally swapped an 03 gauge with different numbers into my 09 and I recall it reading different numbers which is how I caught it. My memory also ***** so I could be dreaming it up. But going off of memory

You cannot swap gauge packs unless you swap BOTH, as they are calibrated as a pair. The side cluster is just a slave module to the main one.

 

[Badsnek]

You cannot swap gauge packs unless you swap BOTH, as they are calibrated as a pair. The side cluster is just a slave module to the main one.

….yes I swapped the entire row of aux gauges….I was not saying I only swapped the oil pressure gauge. My car came with Canadian/Metric gauges and was switching over to Standard. Plugged the standard auxiliary gauges in and noticed the oil press numbers were off from where my 04 Gen 3 reads on a cold start. Caused me to walk over to that car and look at the gauge and that’s when I realized I was sent the wrong auxiliary gauges for my 09. When I put the correct gauges in, it read differently from the 03 gauge. Now could that set of 03 auxiliary gauges have been messed up? Sure. Just going off of my experience with it.

 

[Badsnek]

You cannot swap gauge packs unless you swap BOTH, as they are calibrated as a pair. The side cluster is just a slave module to the main one.

Not sure if I’m following on what you’re saying about swapping both. Are you referencing the main Speedo/cluster and the Auxiliary gauges? Or are there even more modules behind the dash that I’m not tracking

 

[Viper Specialty]

Not sure if I’m following on what you’re saying about swapping both. Are you referencing the main Speedo/cluster and the Auxiliary gauges? Or are there even more modules behind the dash that I’m not tracking

Both GAUGE CLUSTERS. The Tach/Speedo and side/vertical gauge cluster assemblies work in tandem.