HI Lately my PSD has been losing oil pressure!! My truck is a 2004 PSD CC SB Lariat, It was made in June It has 90,000 miles. I had an edge module but removed it 4000 miles ago. It has an AFE stage1 Magna Force air box, 4 inch Magna Flow exhaust with no Cat., zoo dad mod, dieselsite coolant filter. The needle on my gauge goes to low when my RPMs are low(650rpm) and my check engine light illuminates but as I speed up it goes quicky to normal. It only happens on occasion but last nite it happened several times as I slowed down to make turns my oil pressure would drop to low but as I push on the gas and my Rpms get higher my oil pressure returns to normal quickly.On another occasion when my oil pressure dropped I turned off the truck and restarted it twice and my pressure returned to normal. Today I used my truck several times but everything was ok. During this low oil pressure situation my truck seems to run fine. A little bit of history on the truck: 2500 miles ago it had the FICM replaced and OIL COOLER replaced, 1000 miles ago it had the head gaskets replaced. My truck runs fine except for an annoying exhaust drone that I never had before the Head gasket change. Now 1000 miles later I am having this oil pressure problem. Any ideas? Oh yeah I have not been using the Edge module .Thanks in advance. Oh I am not sure if this an issue but I always run Synthetic oil 15w40 in summer and 5w40 in our cold winters, BUT when the dealership change my Head gaskets they changed the oil and used non synthetic 15w40 .Last nite we used the truck again and once again (once the truck was somewhat warm)as i slowed down to make turns and as my RPMs went to idle (650 RPMs) I LOST oil pressure and check engine lit illuminates . The gauge went to low. As I pulled up to the turn it would hold the oil pressure at 650 RPMs for a few seconds and then drop to low on my gauge. But If I put the truck in neutral I can rev her up, creating Higher RPMs and the oil pressure rises with the RPMs . As soon as I rev past 650 the pressure quickly. I drive further and it happened at all 3 turns. I shut the truck off and oil pressure was normal again and she kept normal oil pressure for rest of my trip. I parked the truck for approx. 5 hours ,started it and did not really let her warm up and drove 10 miles with no issue,Any help would be greatly appreciated, I am probably going to bring her to a ford dealership but dont want to go in blind and get over charged. Thank you and cheers Mike

 

mike how about some info like what year the truck is? miles ? mods?
different years have different issues. if its an 04 please let us know if its early or late build

 

On my 04 the factory oil pressure guage is nothing more then a glorified idiot light. It's either on or off, I think it only needs 8 psi to activate. Mine acted like yours, changed the sending unit and all is well.

 

its 5 psi to for the sender to activate. depending on the year the issue could be this simple or far more complex. with your 04 you were very lucky. 03/04 has a very unique issue that will cause the op concern as well.

 

Cheezit,
What is the bigger problem? I thought that if you had a true oil pressure problem the HPOP would not be able to fire the injectors before causing major internal damage. I'm no mechanic just trying to get a better understanding.

 

there is a knowen issue with the casting plug popping out on the high pressure oil pump. this only happens on the early style pumps with the cast iron cover. If this is the case there a a fix that is cheeper then pump replacement but the hpp would still need to be removed.I would check oil pressure with a gauge first when the concern is present to see what base pressure really is. also check the sender to see if its leaking oil.

If you have an oil pressure issue the truck may or may not start and may or may not run. All trucks seem to act a little bit different

 

Sorry guys I posted more info on my truck on the previous post. Its a 2004 PSD built in June,etc, mods posted above

 

Hi guys thanks for the input. It was the sending unit. A relatively cheap fix. Once again thanks, cheers