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3.5 efi first start oil pressure problem

series3mad

In Fourth Gear
today i tried to start my newly rebuilt 3.5 efi, i first turned it over with the coil disconnected and got oil pressure, then i started it with oil pressure, then i stopped it and started it again and couldn't get the oil pressure to return.

the only things i can think of are that the oil filter has been blocked by the vasoline from the pump or the pressure relief valve is stuck open.
 
If it's the same oilpump as the early 3.9 you can turn off the bolt in front of the pump where the spring is behind.
Pull out the spring and see if you can press back the relief valve with a small screwdriver, if so the spring has lost it's tension.
Tony.
 
I checked the relief valve which moves freely and the spring still has lots of tension, i have also spoken to RPI and they say that this is happens alot and with all of the messing around i have done, an air lock has appeared in the system they say you have to re-prime the oil pump with vasoline.
 
Can be true. On an older engine I have worked on I had to remove the oilpan because of a leak that had to be welded and it turned out that the oilscreen at the end (beginning?) of the suctionpipe was pretty much clogged of sludge.
This also can be a reason for bad oilpressure, but it's up to you to determine if it is necessairy taking off the pan (overall state of the engine, sludgewise)
Oh, and if you do so, don't forget to renew the gasket between the pipe and the block, here it can suck air.
Success, Tony.
 
I re-primed the pump with vasoline but there was still no oil pressure, then i spoke RPI and they say that if you stick a 3.9 timing cover gasket on a 3.5 the oil pump will suck air not oil, and i'm sure i may have put a 3.9 gasket in.
 
reminds me of the time me and a few friends were about to go out for drinks lol
rob still lived with his parents and older brother, matt asked for something to put on his chapped lips, rob checked the house and found a tub of vasaline in his brothers room.... rob and i noticed the short black curly hair in the tub just as matt started to rub the vasaline on his lips

we never had the heart to tell him lol
 
On a more serious note, before starting my V8 for the first time I removed the dizzy, and spun the oil pump drive up in a drill (using an extesion, socket and some gaffa tape) this put the oil pressure light out and made sure there was oil in all the galeries and stuff for first start!
 
I checked the gasket but it was right so i took took the sump off and found small particles of metal, so the engine had to come out again and fitted new cam, big end and main bearings. i put it back in and spun the pump up with the drill and got oil pressure, then started it and the light went out again (a good sign) but after 60 odd seconds a weird dry sound which appeared to be coming from the back of the engine cropped up i turned it off after a minute i started it again and the same thing happened after 60 seconds the sound started again. so i spoke to a friend and he said it could be either the torque converter isn't lined up or the starter motor not disengaging properly, so i'll change the starter motor and put a proper oil pressure gauge on the car and sea what happens.
 
the noise turned out to be the exhaust manufold bending out against the chassis as the engine wormed up, and the oil pressure now runs at 35psi idle!
 
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