I have a 01 3.9 AT dakota an wanted to know if this is normal on the oil pressure.
After both start up an running down road an for a little bit after the oil guage is a bit high...


seems to go down a bit later also.
Just wanted to know if this indicates anything i should look at or later do.

Thanks

 

Change your oil recently? I know on mine, (full size truck) with fresh oil, pressure is always higher, and will taper off some as the engine warms up. That's normal.

 

Getting ready to change it..I have regular conventional .what weight is best in these trucks ?
Should i use high milage oil or not .

I will look at guage again before and after ..but that reading was in the middle of a change.

 

While there is indeed such a thing as "too much" oil pressure..... (and I have the perfectly spherical oil filters to prove it.... ) I don't think its an issue for you. So long as the gauge stays in the 'acceptable' range, I would just smile, and be happy.

As for oil weight, go by the manufacturers recommendation. I think 10W30 is a good all-around oil. I personally use the high-mileage oil in my high-mileage vehicles. It has a few more cleaning additives, and as my current truck was kinda neglected by the previous owner, cleaning up the inside is just not a bad plan.

 

I use 15w40 Diesel oil in mine, it has more Zinc and other additives that provide better lubrication for older push rod engines than modern gas engine oils do. I use the same stuff in my Jeep 4.0 as well the extra zinc is even more important for the 4.0 since it has a flat tappet cam.

 

Thats interesting to use that type oil with zinc , in the dodge .
Ive been using 10w30 conventional an was going to try high milage 10w30 .Im looking for a bit better milage also.

 

They also make 10w30 conventional and 5w40 synthetic diesel oil if you want to give them a try.

 

If you've got high oil pressure, running high viscosity oil or diesel oil is counter intuitive.

It's 2019.... I'd be running a thin full synthetic in that engine if I were you. I'd also seek out a larger, non-restrictive oil filter. Right now I run 0W20 with almost 300K miles on this 4.7L. It's also possible that your oil pressure sender is headed south.

 

Yes it's 2019 but the basic design of the 3.9 dates back to the 60s. The 4.7 is a completely different engine all together.

 

Yeah, but he's complaining of high oil pressure. High viscosity will only worsen the problem. I said 2019 with regards to oil technology, not engine design. 0W20 has a tough oil film that will flow easier and clean better.

There are two three things that could be causing his issue in no particular order....

Oil blockage (this is where a thick oil would cause more issues)
Failing oil pump (although that usually causes pressure loss)
Bad sender

I'd put a mechanical pressure gauge on it.

Oh...I forgot a fourth reason that oil pressure could be high....excessively thick oil.