Hi All, my truck has recently presented a new issue.  The oil pressure reads rather high, mostly all the time on the gauge on the dash.

 

I'm thinking the oil pressure sensor could be failing, but I would rather make sure my oil pressure is correct.

 

The bad news is I'm about 200 miles away from home for the next week and don't have my service manual with me (doh!).

 

The good news is I have access to tools so I may be able to solve this while I'm here.

 

I have a mechanical oil pressure gauge and was thinking about testing the pressure first before making assumptions, does anyone know if anyone posted an article about how to properly run the mechanical oil pressure test on my 2001 5.9?

 

Also if it is the sensor does anyone have any thoughts on the best replacement part to get with?  Are there any good lower price aftermarket units or...?

 

Thanks in advance for the help.

  On 6/7/2019 at 10:48 PM, leety said:

Looks like it's 44 ft lbs.

 

I like to measure stuff, just because.

Nothing wrong with that. Did alot of torquing on the head gasket replacement. Just never torqued an oil pan plug. 

@dripley

Oil pressure relief valve plug not the oil pan.

 

  On 6/8/2019 at 12:39 AM, Mopar1973Man said:

@dripley

Oil pressure relief valve plug not the oil pan.

 

Pretty sure he asked about the drain plug. 

  On 6/7/2019 at 10:27 PM, leety said:

Can you tell me the torque setting for the drain plug please?

 

 

You guys crack me up.

This just in.

 

Motor @ normal operating temp getting just south of 30 psi at idol and about 73 psi at about 2k rpms.

  On 6/8/2019 at 2:45 AM, leety said:

This just in.

 

Motor @ normal operating temp getting just south of 30 psi at idol and about 73 psi at about 2k rpms.

 

Thats in the filter head? 

 

Seems about right. 

 

How old was the oil you changed? 

Edited June 8, 20195 yr by AH64ID

Good thing you didnt change gear ratio and swap to higher bar injectors for that fix.

 

 maybe the straw to blow off valve was plugged and new oil cleared it out.

  On 6/5/2019 at 10:00 PM, AH64ID said:

Still not seeing how a filter can increase pressure after the filter. Not sure it’s physically possible.  

 

Filter itself can't increase pressure it will simply go into bypass mode and continue to flow. I totally agree...

  On 6/8/2019 at 12:50 AM, AH64ID said:

 

 

Pretty sure he asked about the drain plug. 

 

 

She asked about the drain plug :-)

Well it seems the display on the dash is reading a high pressure when the engine is at full operating temperature.

 

When measured with a mechanical gauge the pressure seems high 75+ when cold and fine 30-73 at normal operating temp.  These measurements were taken pre oil change.

 

I pulled the plug and filter to drain overnight yesterday.

 

I will measure again after I put the new oil in to see if the pressure is still high when cold.

 

I don’t have my records with me to see when I changed the oil last, but I think it is about due.

 

So what should I check next to figure out how to fix the incorrect reading on the gauge on the dash?

The sensor comes to mind, Could be failing but not enough to trip a code.

When I don't have time for an overnight draining and a little overdue, I like to pour an extra quart of oil thru the engine with the drain plug out. Wasteful perhaps, but the cold oil running into the dirty warm oil, you can see pushes more dirt out. I do it every once in awhile.

Rotella 15w40 & on cold start with Autometer gauge at oil filter head I have 38psi idle and 85psi 2000 RPM. Hot idle 30psi idle, 75psi 2000 RPM. Factory dash gauge reads a few pounds lower but seems to mirror movement.

Be aware of the dash gauge its not exactly a accurate gauge. 

 

 

 

Take note this video is really old being I've not used a Edge Comp in a long time.

Edited June 9, 20195 yr by Mopar1973Man

  On 6/9/2019 at 1:42 PM, Mopar1973Man said:

Be aware of the dash gauge its not exactly a accurate gauge. 

 

 

 

Take note this video is really old being I've not used a Edge Comp in a long time.

trippy

@Mopar1973Man  Correct me if I am wrong but this is on your 02 with the one wire switch and not the earlier years with an actual pressure sensor. My 02 is the same way. I wonder if the earlier years react the same way.

It is a pressure sensor. Even though its a single wire. 

  On 6/9/2019 at 2:22 PM, Mopar1973Man said:

It is a pressure sensor. Even though its a single wire. 

I realize that but the gauge would receive the signal differently would it not? Ours just closes a switch when pressure is detected then the ECM takes over using rpm and ect for the pressure reading. The early ones actually read the pressure and send that on to the gauge. Just makes me wonder it the early models are wonky like that.

02’s (and anything after) don’t have pressure transducers, just pressure switches. The dash gauge is 100% fake. 

Edited June 9, 20195 yr by AH64ID

Not exactly.

 

It is a pressure transducer but just a 1 wire. It does have a variable resistance to ground. It is NOT a switch with open (infinite ohms) and closed state (0 ohms). ECM is creating a weird value from that which follows some weird software math. 

 

 

Pressure transducers have to have more than 1 wire. 

 

Pressure switches can have 1 wire thou. 

 

It’s a well known change from 02+, and even some earlier models have software upgrades that treat the transducer as a switch.