iwillnc

I just replaced the oil pump, pickup o-ring, and pressure sensor on a 2003 LQ4 with almost 180k miles.

Truck started having low (20-25psi pressure) during driving and randomly had 0 psi one day on crank after getting fuel.

Now have a very strong 45psi idle with new melling pump.

Problem is after sitting for a week or so the oil pressure is 0 on startup and takes 1-2seconds to quickly bump up to 45. Also tried after 36 hours and the truck had 15-20psi on crank before quickly (1-2seconds) building up to 45. After about 30 minutes sitting after crank I’m at 35psi.

Would this be due to oil leaking past pressure release valve on the pump over time?

Is this something to worry about? It could have done this it’s whole life and I would never know since I wouldn’t have known to pay attention.

I repaired this engine in truck and have not given it a full heat cycle yet since replacing pump either.

iwillnc

Nothing? Is this normal, possibly something I just missed in the past? It’s not more than 1-2seconds from the time the engine fires on ignition.

Even if this is not correct I have a hard time believing 1-2seconds would cause concern, should still have oil on the bearing for several months/years in a sealed environment correct?

G Atsma

All is fine and normal. A second or two after a week or more (or even less...) is nothing to worry about

00cls1camaross

iTrader: (10)

My 10295 Melling does the same thing every startup on both my LS powered vehicles.

iwillnc

Thanks guys, I don’t think I would have ever even thought about it if I didn’t notice the gauge start above zero on a test crank.