Oil Pressure Nailhead 425 1964

[Fruck]

Hello everyone,
Hade the oil pan down to clean the screen and check the oil pump (this result. Timinggears had been losing some plastic crumbs that was blocking the screen).
I have driven the oil pump with a drill so I've seen it coming (little) oil upat the rocker shaft but I get no oil pressure, the lamp goes out not until therpm is pretty high and if I connect on anoil pressure gauge is also very bad. This applies to both the drill and theengine runs.
Ideas what is wrong in the engine?
Can mention that I changed the timing set, oil 2 times and filter 3 times.
Thanks in advance.

[Bob]

How many miles on the engine? Plastic timing sets often start to come apart somewhere up of 100,000 miles, and those engines are usually tired, worn out, leading to low oil pressure. You might like to do a compression test to help assess the condition of the engine.

[bob k. mando]

Timinggears had been losing some plastic crumbs


how long had the engine been run with low pressure before you cleared the screen?

where is your oil pressure gauge plumbed too? where the idiot light sensor is plumbed?

basically, there are two primary possibilites:
1 - the pump is not generating pressure, in which case the gear teeth need to be clearanced ( especially on the sides ) and you need to double check the entire pickup to make sure that the entire line is clear AND that there are no holes or sealing problems

2 - the pump is generating pressure but the bearings are already shot and all of the oil pressure is being blown out around the first couple of mains bearings

Nailheads are not generally known for oiling problems so you might just want to plan on a basic teardown and new gaskets / bearings / rings.

[Fruck]

Timinggears had been losing some plastic crumbs


a)how long had the engine been run with low pressure before you cleared the screen?

b)where is your oil pressure gauge plumbed too? where the idiot light sensor is plumbed?

basically, there are two primary possibilites:
1 - the pump is not generating pressure, in which case the gear teeth need to be clearanced ( especially on the sides ) and you need to double check the entire pickup to make sure that the entire line is clear AND that there are no holes or sealing problems

2 - the pump is generating pressure but the bearings are already shot and all of the oil pressure is being blown out around the first couple of mains bearings

Nailheads are not generally known for oiling problems so you might just want to plan on a basic teardown and new gaskets / bearings / rings.

a) That is hard to say I guess it has been worse by time
b) Both are at the original place, just shifted between light sensor and pressure gauge
c) If I take the oil pump down again and run it by a drill in a bucket or something like that, is it possible estimate if it has enough flow?

[bob k. mando]

i think i've already linked the Service Manual for the 425ci? if not, it's here:
http://www.teambuick.com/reference/l...chassis/60.php


if you look at figure 60-124 ( on page 60-103 ) you can see that the oil filter is the first thing in line on the pressure side of the oil circuit. *all* pressurized oil passes through the filter.

therefore, if you have pressure in the filter you SHOULD have pressure available for the engine.

take the filter off, put a bucket under the fitting and have somebody else run the drill. oil should pour out of the filter housing when the pump is running. i suppose you could also rig up some kind of a fixture to screw onto the filter housing that would allow you to read pressure.

after oil comes out of the filter, it feeds the crank mains and cam bearings and moves to the front of the block. at the front, it weeps out on the timing gear and gets funneled up to the rockers and lifters.

i'm not sure where the factory sensor location is but 'proper' placement would be at the opposite end of the block from the pump. ie - it should be plumbed at the front of the engine to the main oil gallery.

this way, IF you lose main or cam bearings THEN you will immediately see your oil pressure loss before really serious damage gets done.