adam1803

iTrader: (65)

I got my new 408 to where i was ready to try and start it today. I pulled the coil plugs and fuel pump relay and cranked it over a few times to prime the system. When i plugged them back in i was happy to hear the motor crank right up, but after 5-10 seconds i still had 0 oil pressure.

I then got a little ahead of myself and took apart the front cover to check the pickup tube oring. It seemed ok but while its apart im just going to get a new one anyway.

Then it hit me to check the oil filter and see if there is any oil in it and there was. Now theoretically, if there is oil in the filter, it had to have been pumped in there from the oil pump right? And the gauge wouldn't show oil pressure until the filter was full because the oil goes from the pan, to pump, filter, bearings, and then the sensor right?

Quik

iTrader: (7)

is it a fresh block? if so you might not have the proper plugs and plunger in the oil passages as needed. my fresh block didnt have the needed parts. also ther are Orings for car tubes and truck tubes.

also check your sender it might be bad

adam1803

iTrader: (65)

i forgot to mention that i already checked the front oil galley plug, and im positive that the rear one is installed.

Also i dont think it could cause no pressure, but when i installed the spacers on the pump for my double roller, i made sure they were oriented correctly, but didn't put rtv on them like most say you should so i'll do that when i put it back together.

adam1803

iTrader: (65)

That might be the problem, the pickup tube is from a truck but the oil pump is an LS6 pump so it came with what i assume would be a car o-ring. (it was blue if it makes a difference)

adam1803

iTrader: (65)

well i got it put back together today and still no oil pressure. I squirted oil into the sensor port, filled the filter to the top, cranked it with the coils unplugged and fuel pump relay out, then i started it and let it run 6-8 seconds and didn't get any pressure. I swapped out the sensor and still got nothing. I even hooked up my hptuners to it and for some reason it just reads -15.4psi.

I ended up taking off the rear cover and the gasket was a little messed up where it seals around the oil passages near the top of the block. I got a new gasket today and i'll swap it out tomorrow and see if it helps. Im also going to throw an old oil pump on it and see if it works. I have a brand new pump on it but i guess its possible that its bad.

thunder550

iTrader: (70)

I have read before that to see pressure when cranking you need to crank for 30-40 seconds. Don't worry about seeing pressure when you're cranking. Just make sure that when you fire it up for the first time that you watch that oil pressure gauge like a hawk.

adam1803

iTrader: (65)

ive already fired it up because i've read lots of people on tech saying that cranking it with the starter is not enough to prime it.

I replaced the rear cover gasket tonight but as i thought it didn't help at all. I hooked a mechanical gauge to the port by the oil filter and cranked it over. I figure if the pump is pumping at all i should see something from there and i got nothing, didn't even get oil start flowing through the line. This really screws me up because the filter is full of oil and i didn't fill it when i put it on.

quicksilverado

iTrader: (8)

Make sure the rear plug is installed. That will cause your symptoms. Seen it before.

adam1803

iTrader: (65)

that was one of the first things i checked.

Quik

iTrader: (7)

listen carefully and see if you can answer these questions

is it a fresh block?
did you assemble theblock your self
when you had rear cover off did you happen to see a brown/tan plug on the left side of the block?

this plug is actually a plunger. it goes into the valley which is how you have oil psi. what happens is it goes from the pump to this plunger and sneaks past this and up thru the back of the block, youll see a valley that goes diganaol [sp] it then goes up to the oil pressure sender along the way it pumps oil into the cam area and then rest of motor. if this plunger is not in place you will not have oil psi.

you can see this without rear cover off by looking on driver side of block. there is a allen head plug you need to remove and shine a flashlight up in the hold if possible and see if you see a small tube. the tube is part of the plunger

also in front of motor on pasenger side i believe there is a softplug you should see which holds oil in the valley

without both of these you will not have oil psi