Thread: Anyone have low oil pressure readings w/ GFD oil line?

So, I've had my motor sitting for about a year now since I rebuilt it. Its read low oil pressure since I first cranked it, and I havnt really run it for more then a few mins at a time since. I finnaly got some free time to look into it, and I'm beginning to think its the GFD oil feed line I'm using making my inline gauge read low. On cold start it reads about 37-40psi, and drops to less then 10 psi when warm at idle (but the stock oil warning light never comes on...)

I've tried 2 different gauges (one mech, one electronic) and I have a brand new oil pan installed, so I'm 100% positive its not dented.

Has anyone else ran into similar issues w/ their GFD oil pressure line?

that sounds fine to me for a DE or DET motor, that is how all of my have been except the latest one, it reads about 20warm at idle

The gauge is reading 0-5 at idle warm.

i have the exact same prob, when i start it its at about 40-45 then when warm gets to like 5

dont worry i found out what it is, the motor doesnt have low oil pressure, its where the sender is, its just getting an inaccurate reading because the sender is in the wrong place and isnt getting the right pressure reading

this is how mine looks now, sender unit going off the T





now i was told since the sender unit is on the bottom of the t and not on the straight part that it wont get a true reading because its not getting a constant flow and that the turbo it getting to much oil hence why mine smokes a little so i was told it should be switched around and put like this to get a correct reading



this way the sender is getting a direct pressure since the oil is going straight into it and not being send off another way

i havent tried it yet but im sure it will fix it

hope u can understand it

..........

I believe all he is saying is move the sender prior to entering the T instead of exiting the T.

Yea I had the same problem. Move the sender unit on the straight portion on the T so it gets direct pressure and a correct reading.

Thanks for calling me on this.


That is exactly what I told s132nr. The sensor was never designed to be relocated, so at idle while the rpm's are low the sensor will read low. At normal driving speed where the rpm's are high there is enough pressure flowing so that the senors reads correctly.

If you guys have any questions please feel free to ask!

Hmm, I'd never have known because I don't have a gauge on my oil pressure. I just relocated the stock sensor to the section of the "T" as shown in the first pic. I can see why changing things around would help. As is, I have no issues with my oil light coming on (I assume if it saw 0-5 psi at idle it would, but that's maybe putting too much faith in the stock sensor). Maybe I'll swap things around anyway.

By the way, are the rest of you routing the line across the rear of the engine towards the driver's side and then along the block by the transmission and then to the turbo, or are some people running it the other way? Just curious.

It really doesn't matter where the sender goes. The physical properties of a fluid dictate that the pressure will be the same regardless of bends or whatever. The fluid that goes straight through the T reaches a point of restriction, and creates back pressure along the line that is equalized. Am I explaining that in an understandable way? I'm no teacher, but what I'm trying to say is that it really doesn't matter where the turbo line is and where the sender is.

Yes, Ben, I'm running my oil line just the way you described.