89 oil pressure slow coming up

[WBegraft]

i got an 89 5. 9 its got almost 400k it runs great as always but the oil pressure comes up real slow it takes at least 30 seconds to reach 50 psi at idle its been like this for a while it didnt just happen one day and once its up its fine and stays there just wondering what the cause is maybe the oil pump? oh yeah i'm using an aftermarket mechanical gauge thanks

 

[AKimmel]

The tube going to your guage could be getting clogged up. I have a friend who ran the normal 1/8 line to his oil pressure guage on his circle track car, and was loosing oil pressure in the turns from the oil sloshing away from the pick up tube, but it never showed on the guage. He replaced the line with a 1/4 inch braided one, and he got a more instantaneous reading, which showed the loss of oil pressure.

 

[bgilbert]

i got an 89 5. 9 its got almost 400k it runs great as always but the oil pressure comes up real slow it takes at least 30 seconds to reach 50 psi at idle its been like this for a while it didnt just happen one day and once its up its fine and stays there just wondering what the cause is maybe the oil pump? oh yeah i'm using an aftermarket mechanical gauge thanks

Sounds normal. As long as it's within spec, I wouldn't worry about it. Does your factory oil pressure buzzer or light (junk) stay on for 30 seconds? It will take longer than you would think for even a built 5. 9 to build oil pressure too. Mine (not built) takes quite awhile to build on the mechanical oil pressure gauge. Even longer when cold.



Wanna know if your oil pump is working good? Just do what I did, while I had the front cover off the engine, I started it to see how my recent pump gear advance sounded. In just a few seconds it was slinging oil all on the floor and under the hood. I'm sure my truck has about those many miles too.

 

[WBegraft]

thanks for the replys the factory o/p stuff hasnt worked in a couple hundred thousand miles i was just curious wether or not this was some kind of sign of things to come but its been like this for years with no trouble so i'm not stoppin till it goes to half a million

 

[dpuckett]

Until it starts to make some weird noises, I wouldnt worry about it. While I dont have a mechanical gauge, I have installed one temporarily in the filter housing next to the turbo oil supply line. Pressure built up faster than I could run around the front of the truck.



FSM says a cracked oil pickup tube can cause a slow build in oil pressure. Kinda like sucking soda through a cracked straw- takes a while to get where it needs to go.



Daniel

 

[WBegraft]

yeah it probably has pressure pretty quick to the bottom end which is the most important... . the gauge is usually the last place to see the pressure