I have an 04 rcsb 1500 with a swapped lq9 and ls3 heads/intake. Unfortunately I lost traction on the freeway onramp in the rain at about 40 and swerved to the right on the shoulder and bounced off the wall, hitting the front corner of the truck... and then the back came around and slapped it near the taillight. No damage to the frame, suspension, and the engine looks perfect as usual. Just the corner of the hood, the pass. side fender and corner of radiator brace was damaged, and both side wheels.

Anway I had the truck brought home on a flatbed, and ever since then when I start the engine the oil pressure guage slightly movies for a split second then stays completely at 0 and I get the "low oil pressure" in the message sensor. The top end sounded more noisy than usual, and I mech guaged it today and there is no pressure at all. What could possibly have been damaged during the collision to cause this?? Im hoping it's just the fuel pump, but how/why would this break after the accident?

 

There's oil in it, right?

 

Does it have an auxilery cooler? You could have snapped the lines. Or you could have broke the sender/connector on the back of the engine valley if you hit really hard, when the circuit it open it defaults to 0 psi.

Worst case you could have run the pickup dry spinning around, don't think it's all that likely though.

 

It's out there but the bypass in the oil pump could have popped open and stuck? Since you already checked it with a mechanical gauge the next cheapest fix is to try an oil pump. Unless you have an oil cooler line kinked if you kept the cooler.

 

fresh synthetic around 500 miles ago. it could actually be a pinched cooler line i can't see, i'll have to look closer in the morning! sending unit looked fine to me. i haven't driven it since the accident, other than running it maybe twice in the driveway for less than a minute, could that be enough to do damage?

 

if you have no oil pressure DO NOT RUN THE ENGINE!!! You can damage the cam lifters and alot of other things. Check the lines for the oil cooler. If not you might have to replace the oil pump.

 

Running for even a few seconds with zero oil pressure wil damage the engine, I know cause I've done it. Did the oil cooler break?

 

it's got the 34" radiator with no cooler lines ran. should i try replacing the sending unit? i don't see how the oil pump could have just broken after a slight impact to the corner of the truck

 

You said you tried a mechanical gauge and had no oil pressure? All that leaves is something oil pump or oil filter related.

 

It could have wedged the oil pressure bypass open.