I went to Bass Pro Thursday to pick up some stuff. On the drive, oil pressure was good. 40 psi at idle and 60psi at speed. Parked the truck, picked up stuff and went to start the truck. Truck started fine, no peculiar noises but the oil pressure light comes on. Look at the gauage...0 psi. Immediately turn the truck off. Less than 10 seconds of run time. Thought maybe it was a sending unit so I pull the oil cap to see if I get return oil from the STS scavenge pump. Restart the truck for about 5 seconds...no oil and shut it off. Had it towed to a local repair shop.

Before they dig into, anyone got any ideas about what it might be? The only abnormal noise I heard was normal clatter of un-oiled valves for the few seconds it ran dry. Nothing else.

Would I hear a spun bearing? I did a search and came up with a blocked pick up tube or stuck bypass valve. Got any thoughts on other possibilities? The shop will be dropping the pan tomorrow and the starting price is $1400 to replace the oil pump.

If anyone knows a good shop in the north Dallas, TX area that would be more reasonable, bring it on. I need all the help I can get right now.

 

I had this happen to me twice. Bypass valve on the oil pump gets wedged open with a small piece of debris. If you replace the pump or pull the plunger/relief valve apart and clean it you should be fine. You didn't hurt anything either with only 10 seconds of run time at idle. $1400 seems pretty steep for a pump replacement, but I guess it depends on what their hourly labor rate is. I picked up a new oil pump for $90 at the dealer and did it myself, took about 6 hours because mine was 4wd and I had to pull the front diff.

 

Thanks for the reply Thunder. $1400 did sound kind of steep but it is 4WD and it always seems steep when you think you could do it yourself. Price of admission when you're covered up at work, I guess.

I guess my next question would be, what kind of debris is floating around in there that would clog it up and do I need to look into that?

 

pm sent, if the above soes not do resolve the issue.

The shop I am using says they can do a high volume pump for $680 but says you will need the mains too. Once you loose oil pressure you really must replace that too. The mains is $350

Total $1030 ish by the owner of the shop.

 

No, you don't need to replace the mains. That's BS. And you don't need a high volume pump either. OEM is perfectly fine, and you can shim the spring to change the oil pressure to compensate for looser tolerances if needed, although based on his sig it looks like his internals are stock, so a stock pump is all that will be needed.

To the OP: Could be dirt, or tiny pieces of bearing material, lots of different things that could cause it.

 

Why does this always seem to happen when restarting the truck, rather than when it is running? Does the plunger close down on the debris when the truck is shut off, causing it to not flow properly when restarted?

 

As it was explained to me, that's right.

 

Im in Austin and Ill drive up there and change the damn thing for you for half that price

Its really not that big of a deal, I do it withouth pulling the diff, you can drop the pan just enough to get to the bolt on the bottom of the oil pan. Its a pan getting to the pain bolts since some are on top of the diff and hidden but its not too bad.

I wouldnt pay more than 800 for a shop to do it. Might as well get a nice cam thrown in there too while youre at it.

 

for the price that shop wants, you should at least get a reacharound, cause your getting screwed. hope you get it straightened out soon.