Hello,

I recently purchased a 2000 RT which seemed to have weird oil pressure symptoms (oil pressure would behave normally until 190 degrees, then would drop to just below 40 no matter what).

I changed the oil pressure sending unit--which had a small leak and the housing was a bit loose.

Now the oil pressure seems much better, but I've never owned a Dodge V8, so I'm wondering if my current oil pressure is normal or good/bad for this engine?

Oil pressure is high (50-60) when cold, once operating temp is reached, it idles just a bit below 40. When accelerating, it will go back up to 50-60 and when on the highway doing 60-70 with cruise control on, it stays just a bit over 40, but will rise to 50-60 if I accelerate hard to pass someone.

So, does this sound good/bad/normal?

Thanks for any help,

Heekma

 

Well naturally oil pressure will increase or decrease with engine speed.

 

Hey MoparMan,

I'm not being snide, but I realize oil pressure is driven by RPMs, I'm just wondering if the ranges and speeds I've described would be considered normal or even good, indicating a well-maintained engine, or if they're normal or on the low side.

I purchased the vehicle from the original owner with 120,000 miles on the clock. I know nothing about the previous owner and always take claims of "changing the oil every 3,000 miles" with a very large grain of salt when dealing with a total stranger.

Best,

Heekma

 

whats considered "Normal" by Dodge for the 5.9l engine is between 30-80 PSI. With that said our trucks seem to have a cheap oil pressure gauge that a few have had issues with the sending units failing multiple times. I would strongly advise you to install a mechanical oil pressure gauge in there somewhere.. Don't have to be the top $$ ones, i personally have a $20 one from advance sitting on my work bench waiting to be installed.

If you really wanna go all out you could also do what i have planned... I am gonna be installing a dual A-Piller pod and including a trans temp gauge with my oil pressure gauge that way i can keep and eye on the trans too... HTH

 

+1 old_school, the oil pressures seem fine to me, my truck idles anywhere from 25-30 when warm and cruises on the highway at 75, spikes as high as 90 when driving with a cold engine in the winter, and idles around 70-75 when cold in the winter

 

Thanks for the info folks, much appreciated.

I purchased this vehicle from the original owner (a widower) who seemed to have done a good job keeping up with oil changes, but not with transmission servicing (just had the transmission rebuilt after purchase).

After the transmission rebuild, I've been hyper sensitive about just about everything.

After the posts from members as well as reading a bit and consulting some relatives who have been professional mechanics for years (mostly 50s-80s vehicles) I feel a lot better about my oil pressure readings.

I initially felt relatively high oil pressure was a good thing, but after being schooled a bit, I realize high oil pressure is like high blood pressure (blockages increase pressure--not a good thing).

It seems my motor is doing pretty well considering the mileage. Oil pressure of @30 at idle, 40-45 at modest speeds as well as highway speeds, increasing pressure to 50-60 under hard acceleration, dropping back to 40-45 when cruising probably means very adequate oil flow.

Sorry if all this is boring to some folks. I know a little more than to be dangerous (I can replace alternators, water pumps, plugs, wires, cap, rotor, brakes, etc.--the easy stuff) but I'm by no means a professional mechanic.

I'm just happy to know my engine will likely last far longer than it will take me to save up enough money to replace it.

Thanks for reading,

Heekma

 

Glad we could help!

Since you have a fresh tranny in there might not be a bad idea to add a trans temp gauge to keep an eye on the temp, even more so if you plan on using that rig for towing.. Also, don't ever let a trans shop talk you into a transmission power flush unless you like rebuilding stuff long before its due..

 

Hi Old School,

I'm with ya on the transmission flush. I don't know a lot, but I do know a transmission flush on an unknown transmission with high miles has a good chance of leaving you without a working transmission.

The shop I used even said as much. They saw some shavings in the pan, said they recommended a rebuild, not a flush. FWIW, they're the oldest transmission shop in Dallas, with a stellar reputation. They rebuild their own torque converters (heavier duty than stock) and offer a 5 year/50,000 mile warranty.

As long as I maintain the transmission, I think I'll get plenty of service out of it.

The R/T has a transmission radiator in front of the motor radiator--do I need a gauge as well? (I won't do much towing)

Best,

Heekma

 

Its not a critical thing but, more of a piece of mind thing.. i personally would put a gauge on it if i where in your shoes but, i am OCD when it comes to my truck. If you do go though with it do yourself a favor and but a temp sensor manifold kit that goes in the trans cooling line that way you can get the temp of the fluid going out of the trans to be cooled. Its the most accurate to what the trans is running IMO.