oil pressure problem???

[defa]

a mate of mine has a hz ute with a 308 in it. when he bought it, it had no inlet manifold on it and had one buggered lobe on the cam.. so he bought a stage 3 cam, can't remember the brand and new lifters and gaskets... i put the cam in ages ago and hadn't got it going cos it wasn't turning over properly. ended up being an earth problem. but anyways, that is besides the point.. it is now going. starts really well. runs nice and lumpy.. BUT one lifter is noisey. i pulled the rocker cover off and the noisey lifter has no tention on it. ya push the push rod down and it is too springy. so i am thinking it is either buggered or isn't getting enough oil into it..

the second thing is.. it has an oil pressure gauge. the oil pressure is very low on idle and when warm goes to nearly nothing. then to nothing. ya give it a rev and it goes up to about 40 psi... i was holding it at i don't know how many rpms, i would be guessing under 3000 and the oil pressure was going over 40 pis then abover 40, then under and so on...

so i am thinking these two problems would be cos the oil pump is buggered...
does anyone else have any idea's????

 

[Boonz]

check the clearance of the gears in the oil pump, then the bolt torque for cover bolts as they are kinda important for making correct oil pressure...

 

[defa]

i reckon it does leak a little bit from the oil pump.
what clearance are the gears supose to have and what torque are the bolts supose to be

 

[Boonz]

got a gregories?? i dont know of by heart and im not near any workshop manuals but i could find out tommorow for you if no one else can.

 

[RVK 355]

is 40psi the most it will get,what dose it get at say 5500rpm?

holden motors are always prone to low oil pressure especially at idle

 

[defa]

it isn't registered and it isn't my ute so i haven't really been reving it.. it will goto about43 or 45 psi. then it starts to go down..
i should take it for a drive one night when i know there isn't any cops about..

 

[lxhatch]

howd you go bedding in the new cam? how long have you had it running for?

makes me think of a 308 at trade school, had to revved it hard to get oil pressure, it wasnt new had been pulled apart weekly for years.... but once it got pressure it was right..

whta number lifter is it and is the rocker getting oil?

 

[ssn8r]

is 40psi the most it will get,what dose it get at say 5500rpm?

holden motors are always prone to low oil pressure especially at idle

that is true

when mines cold start it sits around 40psi at idle and maybe a bit more when driving either way

once its warmed up the oil press will sit to 20 or even below it at idle

we're talking efi v8 here but some thing i suppose in oil terms..

 

[defa]

but it still should not go down to 0 psi on idle, and the pressure shouldn't drop while holding it in the revs

 

[Immortality]

the gregories (for early commodore 308) says oil pressure (hot), idle: 7psi (48kpa, would also asume this to be a minimum requirement); @2000rpm 40-60psi (276-413kpa) when it's cold you would expect to see more oil presure.

as for the lifter, yes they require oil pressure when the engine is running but the fact that you can collapse the lifter by pushing on it by hand suggests that the lifter is faulty

early holden 308's are well know for bleeding a lot of oil pressure, especially from cam bearings (cause the factory gave em very generous clearances) and the timing chain lubrication system(most people weld up the hole as there is enough oil coming back down the front of the block from the valley to lubricate the chain) add to this a worn oil pump and some wear in the mains and bigends and very quickly you have oil pressure problems. you also need to make sure the pressure relief valve is free and the spring is in good working order

never start a new engine dry. always use some sort of lube in the bearings etc to ensure no wear untill the pump gets up to pressure. if you can't afford the proper stuff from the local automotive outlet then buy a jar of vaseline. this stuff is magic and works well. i also pack it into the pump to ensure it builds pressure quickly and doesn't have an airlock. i also fill the oil filter before i screw it on as well.