Holden 304 - no oil pressure

[Mario K]

hi all, i have the same problem. 304 rebuilt no oil pressure. i have filled the oil filter up with oil, removed pressure switch and filled the pump with oil. Maybe 150ml went in to the oil pump, removed coil lead still no pressure. What can i do?

 

[someguy360]

You'll also never get oil pressure from one of those pumps by cranking with the coil lead off, the nature of those external oil pumps is they need to be spinning at operating speed to work, cranking won't build pressure in them.

These engines can be hard to get initial pressure.

I always pack the oil pump with vaseline/petroleum jelly (and I mean pack it, completely, no gaps, no air pockets) and have always had oil pressure on first start. I've not ever tried to pre-fill them manually with oil. Petroleum jelly is how most have done these for decades and is the most effective method.

Is the cam gear meshed with the oil pump correctly and the oil pump drive rod connected to the pump correctly? maybe the pumps just not spinning.

Either way, if this is the first start of the engine be very careful as you've now wiped all the break in lube off the cam lobes be cranking it with the lead off for a while trying to get oil pressure. The flat tappet cams need to be started pretty much instantly and brought up to 2000rpm for 20 minutes to break in.

Excessive cranking or letting it idle etc without breaking it in will end in tears. If it were me I'd be pulling the cam and relubing but thats just me. I've seen what can happen to fresh engines when people can't get them started.

 

[Mario K]

You'll also never get oil pressure from one of those pumps by cranking with the coil lead off, the nature of those external oil pumps is they need to be spinning at operating speed to work, cranking won't build pressure in them.

These engines can be hard to get initial pressure.

I always pack the oil pump with vaseline/petroleum jelly (and I mean pack it, completely, no gaps, no air pockets) and have always had oil pressure on first start. I've not ever tried to pre-fill them manually with oil. Petroleum jelly is how most have done these for decades and is the most effective method.
View attachment 244260


Is the cam gear meshed with the oil pump correctly and the oil pump drive rod connected to the pump correctly? maybe the pumps just not spinning.

Either way, if this is the first start of the engine be very careful as you've now wiped all the break in lube off the cam lobes be cranking it with the lead off for a while trying to get oil pressure. The flat tappet cams need to be started pretty much instantly and brought up to 2000rpm for 20 minutes to break in.

Excessive cranking or letting it idle etc without breaking it in will end in tears. If it were me I'd be pulling the cam and relubing but thats just me. I've seen what can happen to fresh engines when people can't get them started.

i turned the harmonic balancer bolt (24mm bolt) and the oil pump gears turned. so i think i am okay regarding gears. when i removed the oil pump i check the oil pump shaft and it does not turn freely. Only turns when cranking.

I am off to Woolworths to get vaseline.

Will try tonight.

Was going to get a brass fitting, remove oil pressure switch and try to prime the engine with oil, however will try vaseline first.

Question - Will the vaseline damage the engine or break down with the oil?

 

[someguy360]

Question - Will the vaseline damage the engine or break down with the oil?

It just breaks down with the oil, completely safe, obviously dump your oil after cam break in anyway.

People have been doing this with Holden engines for the better part of 50 years

 

[gtrboyy]

Do vaso trick & make you got working oil pressure preferably manual guage.

If it's cranking slowly or only did few rotations it's not really going to suck oil up through air blocking it in pickup pipe.

A couple times I've had to start an engine up for oil pressure to come up....but you'd only do for a few seconds & as very last resort after several failed attempts safer ways lol.

Few dudes on yoputube & maybe here have made pressurised gadgets to pump oil around engine before start up with good results.

 

[Deuce]

I also do vaso in the pump trick.
I don't do half as much as someguy360 though, just enough that it makes really sticky sounds spinning it manually and I'm confident it will pull oil up.
But hey, the more the merrier, as it breaks down into your standard oil and gets drained out 1/2 and hour later or whatever.

 

[EYY]

Yeah I don’t put a whole heap in - just enough to make it suck. Reason being, that it takes a little heat for the Vaso to melt. This means that whilst oil pressure (measured at the pump) comes up immediately, it takes a little longer for the bearings to see some decent oil flow.

Plenty of people pack them fully, though, and I’ve never heard of a failure due to this. Just my preference, is all.

 

[Mario K]

You'll also never get oil pressure from one of those pumps by cranking with the coil lead off, the nature of those external oil pumps is they need to be spinning at operating speed to work, cranking won't build pressure in them.

These engines can be hard to get initial pressure.

I always pack the oil pump with vaseline/petroleum jelly (and I mean pack it, completely, no gaps, no air pockets) and have always had oil pressure on first start. I've not ever tried to pre-fill them manually with oil. Petroleum jelly is how most have done these for decades and is the most effective method.
View attachment 244260


Is the cam gear meshed with the oil pump correctly and the oil pump drive rod connected to the pump correctly? maybe the pumps just not spinning.

Either way, if this is the first start of the engine be very careful as you've now wiped all the break in lube off the cam lobes be cranking it with the lead off for a while trying to get oil pressure. The flat tappet cams need to be started pretty much instantly and brought up to 2000rpm for 20 minutes to break in.

Excessive cranking or letting it idle etc without breaking it in will end in tears. If it were me I'd be pulling the cam and relubing but thats just me. I've seen what can happen to fresh engines when people can't get them started.

It just breaks down with the oil, completely safe, obviously dump your oil after cam break in anyway.

People have been doing this with Holden engines for the better part of 50 years

thanks,

 

[Mario K]

it worked with vaso. WOW............. Rocker cover was off i could see the oil pumping to the head. Thank you all.

 

[someguy360]

it worked with vaso. WOW............. Rocker cover was off i could see the oil pumping to the head. Thank you all.

Common gotchya with Holden engines, you have to forget everything you think you know haha.

Glad it's all sorted