Lightn95

I've got an 04 5.3 truck motor. It ran fine when it was pulled. It Sat on the engine stand since Oct, I drained the oil then. We went to start it and I have 0 psi. Does the oil pump need to be primed? I saw a video from Millen on primping it through the port on the front drivers side with a 3/8" ID hose. But is that only nessary on new builds? Would this motor need to be primed? It's 100% stock, the timing cover hasn't been off.
or do you guys think I have another issue going on?

thanks a LOT!

LS BRAVADA

iTrader: (4)

So I'm guessing you have a gauge that your looking at to monitor pressure.
maybe the pick up tube o-ring is bad. These usually don't need primed.

TrendSetter

I had a 4g63 do this. It sat with no oil in the pan a few months and it wouldn’t make pressure while running when I put it back in the car. I had to pull the timing belt and put a drill on the pump to get it primed. I figure it sitting with no oil in the pan let all the oil run out enough it couldn’t self prime.
I’d try to figure out a way to prime it.

1964SS

iTrader: (1)

How are you reading oil pressure? Electric or mechanical? It should self prime in a matter of seconds.

01CamaroSSTx

iTrader: (3)

Is this an electronic or mechanical gauge and when your drained the engine oil how long did the motor sit without any oil and in what conditions was the engine left in? To prime the oil pump remove the allen plug at the front passenger side of the block and with a 3/8" hose add about a quart of motor oil. Add oil to the crankcase and install oil filter. With the coil packs fuel pump relays disconnected turn the engine over several times to get the oil circulating through the engine. Connect the coils and fuel pump back up and fire it up! If you don't see oil pressure right away shut it down.

01CamaroSSTx

iTrader: (3)

Sorry driver side of the block id the oil fill plug.

Lightn95

I used a mechanical guage plugged into the port on the top drivers side of the block.
the engine Sat from Oct until about April with no oil in it. And we started it last week.
I did see the video on using a tube through the front port low on the block to prime the pump. I just wasn't sure if that's only for new builds or if I should do that since this motor Sat for 6 months.

Michael Yount

iTrader: (1)

When I did my swap, I bought a new crate LS3. It came with a full sump of Mobil 1 oil, but had never been run. In the installation instructions they made clear that priming the system properly was a requirement to keep the warranty in force. I used my Motive Brake Bleeder attached to the port into the oil system on the front/driver's side of the motor just above the oil pan -- pumped 5.5 qts of oil into that part of the oil galley at about 10-15 psig. This filled the filter, all the internal galleys, pumped most of the oil to the top of the motor where it drained into the sump. Fired right up with full/proper oil pressure (after a second or two of clattering lifters).

Are you certain 0-ring between pump and pickup is working properly/the right size?

Lightn95

That what I am going to try to do tonight. I'll drain a quart out of the pan and put it in that port to prime the pump. I'll remove the relays for the fuel pump and the main harness as said above. And turn it over to see if it builds pressure.

The O ring felt good when I put the pickup tube back in. But unfortunately I didn't learn about that being an issue until the motor was already set and wired and ready to go.

if priming the pump doesn't work, I'll try to remove the pan in the car. It's going to be a major pain in the *** because the steering drag link has to come out to get the pan out.

-TheBandit-

iTrader: (1)

Brilliant use of the Motive Brake Bleeder. I forget you can fill it with fluid; I use mine dry when bleeding the brakes, in case the lid comes off the master. One of the best tools I've ever purchased.

blackhawkMC

They won't tell you this because it's uncommon, but you can rent the pressure tank priming systems at O'Reilly Auto. It takes a day or two to show up and you'll get a lot of weird looks at the counter. It comes with 1/8 npt and 1/4 npt fittings, I can't remember if it came with 16mm or if I used an adapter.
https://www.oreillyauto.com/detail/b...r/to02/4700301

I used it to prime the engine and to test my oil pressure gauge.

LS BRAVADA

iTrader: (4)

I musta got lucky then. Slapped it all together and not even the lifters clattered

Michael Yount

iTrader: (1)

The oil galley port wants a 16mm x 1.5 if I recall correctly. I bought a 16x1.5 x barbed 3/8” and slipped clear vinyl 3/8” hose over it.

I’ve used the Motive to pressure test (low pressure) the cooling system and a brand new A/C system before pulling a vacuum.

Lightn95

Primed the oil pump and still 0 psi while turning it over without the relays.
I guess I'm pulling the pan... this sucks !

-TheBandit-

iTrader: (1)

Are you completely sure of your oil pressure gauge? Did you check to see if oil was making it to the pushrods?

Michael Yount

iTrader: (1)

^^^^ What he said ^^^^^ -- I was just about to ask if a valve cover had been pulled while running.

Lightn95

No, I have not pulled a valve cover while turning the motor over. The guage is good. It's not moving at all, not even 1 psi.

Lightn95

You guys convinced me, I pulled a valve cover and turned it over for 10-12 sec. No oil coming out of the push rods.
looks like the pan is coming off. Which sucks!

ffjosh

Mine would not prime with the starter. I started it and had oil pressure in 3 secs

QwkTrip

iTrader: (23)

Mine have always been Torx Plus.