396 lost oil pressure....need big help!

[FLYNAVY53]

My buddy and I flew out to Austin this weekend to pick up the '67 Camaro he just bought. The car ran great all the way to Houston. I noticed the oil pressure dropped to nothing but we both thought that it was an electric gage and the transmitter had gone bad. We limped it to his parents house and jacked it up to find that the entire bottom of the car is covered in oil. That being said, the pan was only down a qt. It is in fact a wet line gage, so quite clearly the pump has stopped pumping in addition to the fact we have a fairly significant leak somewhere in the vicinity of the rear or the motor.

Does anyone have any thought as to what direction to go in order to continue to troubleshoot? Based on the fact that pressure dropped off, but the pan was still more or less full, Im inclined to assume its a problem with the pump. We did top the oil off and briefly fired the motor back up and had no oil pressure. I traced the line from the gage all the way back to the fitting on the front of the block and there are no kinks or leaks.

Any help would be greatly appreciated as we're supposed to have this thing back in Norfolk VA by Wednesday.

Thanks guys!

[66 tintop]

Pull the distributor and see if the tang on the shaft is broken off, as for the leak who knows where that is ? Best of luck !

[TheJDMan]

Pull the distributor and check the drive gear end to make sure the roll pin has not sheared off. If the dist is OK then look down the dist hole and see if the slot in the top end of the pump shaft is intact. If those look OK then get an electric drill and an oil pump priming shaft available at most auto parts stores or speed shops which will allow you to manually spin the oil pump clockwise and watch the oil pressure gauge. If all is working you should be able to spin the pump with the drill and see it build pressure on the gauge. If you don't see pressure on the gauge you can disconnect the gauge line at the engine fitting and spin the pump again briefly to see if oil comes out of the fitting. If oil does come out you may have a problem in the gauge, if no oil comes out you will need to pull the engine and start looking for an internal problem.

Good Luck!

[71RS/SS396]

If you drove it any distance at all with no oil pressure.... the bearings are most likely toast.
Pull the oil filter and cut it open and check for significant metal in it, if there's metal you have your answer.

[David Pozzi]

Big blocks are known to have the oil pickup tube come loose where it presses into the oil pump. Drain the oil and thump the pan bottom and see if you hear the pickup rattling around on the bottom. look up through the drain hole and see if you can see anything. Fish a wire up the hole and see if you can move the pickup.

With oil at the rear of the block, I'd suspect the oil pressure gauge line is leaking. Those plastic lines break easily. Stereo shops frequently break them when installing equipment on older cars. The other weak spot is the rear of the intake manifold valley seal. If you have an electric oil pressure sender, I've seen those leak, they have a diaphragm in them. Did the (hydraulic) lifters start rattling? If you had no oil pressure, they would pump down and you'd get valve noise. If the oil pump wasn't pumping any oil at all, you wouldn't get debris in the oil filter, but it would be in the pan. You can have the pan oil tested for wear metals. If you truly lost all oil pressure, the car wouldn't go more than a mile. It may be that a metal shaving stuck your oil pressure relief valve open, bypassing most of the pressure, or the distributor drive shaft failed where it drives the oil pump. if the distributor gear failed, the car would not run.
David

[reschke18]

David is right. If you had zero oil pressure the engine would be toast. You need to crawl under the car and thoroughly investigate where the oil leak is coming from. How high/far forward is the oil? I'm bound to think the oil pressure issue and the leak are related. If it is coming from the back of the motor, the rear cam plug could be to blame. (I've lost all oil pressure due to cam bearings before, so I always look at everything to do with the cam.) The rear plug would explain oil loss and pressure loss. Also, as David said, check/replace the oil pressure relief valve. It is the part the oil filter screws onto and my be bleeding the pressure if they are not related. Hopefully it is just a cracked oil sender line! Best of luck!!
-Craig