Chevelles.com banner

21 - 40 of 59 Posts

·
Registered
Joined
·
567 Posts
Discussion Starter #21
If it is going back to zero on a fresh engine you really need to find the problem before you run it any more. I have had a couple of pump relief valves stick open but they still usually had 15 or so lbs of pressure if not more.


I would definitely cut the filter open.



Definitely hook up a mechanical gauge.



What does it do off idle when hot, does the pressure come right up ?
Thanks - I will definitely take this advice before pulling the pan. When hot, as soon as i hit the throttle pressure is up again 60lbs or so.
 

·
Registered
Joined
·
567 Posts
Discussion Starter #22
Notice the dominator and factory SS hood. I may be regretting no air filter!

I was already going to pull the transmission because of a leaking seal, might as well disassemble it all :)
 

·
Super Moderator
Joined
·
12,634 Posts
Notice the dominator and factory SS hood. I may be regretting no air filter!

I doubt that anything would go through the air cleaner and get into the oil pump. But still not a good idea to drive around on the street without an air filter.
 

·
Premium Member
Joined
·
4,913 Posts
The main thing to remember is that this is NOT normal.

Just about any engine will have a drop in oil pressure at idle, if it is at 60 psi at 2000 and above, expect around 25 at running temperature when idling.

If it is not the gage, get ready to pull the pan and find out what's going on.

The problem could be as simple as a stuck oil pump relief valve, or something as serious as a spun bearing.
 

·
Premium Member
Joined
·
1,712 Posts
Notice the dominator and factory SS hood. I may be regretting no air filter!
Yes you will! When I first did my 540 many moons ago, while doing 13 pulls on the engine dyno, we drained the oil and changed the filter twice. Then once in the car, I drained the oil again after about 100 miles of street driving. I took the oil and had it analyzed by a company that specialized in engine oil analysis. Everything was good except the level of silicon was higher than normal for the mileage on the motor. I asked them where the silicon would be from. They said its DIRT from inadequate air filtration. I was using an oiled K&N filter element! I contacted K&N. They told me it most likely was getting around the element and told me to put a light coat of grease where the element contacts the filter housing top and bottom. 12 years later upon tear down, everything looked real good.
You really should run a filter, especially for street driving.
 

·
Premium Member
Joined
·
305 Posts
It is the spring / valve in the oil pump itself . Remove pan , Remove pump . Remove the 5 bolts holing the pump cover on , drive the roll pin out that retains the spring and valve and check for debris.


Worst one I have seen was on a friends 396 , same description as yours , 60+ psi when RPM'ed , Zero at idle . Found a piece of wire from a wire cup brush lodged in the valve . Apparently he used that tool to clean gaskets when swapping intakes ........


Seriously , it really doesn't take much to jam it up , it is a tight tolerance in the bore .


Good luck


TOM
Years ago I had a Mustang that I lost oil pressure in after some engine work. I found a wire from a wire brush lodged between the oil pump gears. It locked up the pump and caused it to snap the oil pump shaft. Fortunately I shut the engine down as soon as I saw the oil pressure drop and didn't do any damage. Replace the oil pump and shaft and have never used a wire wheel or brush to clean gasket surfaces since.
 

·
Registered
Joined
·
25 Posts
Could it be possible that the "Pick up" on the oil pump cam off?
I had a friend with a 396 this happened to.
My engine builder tack welded my pickup to my oil pump and I have had no issues.
Just a thought....
 

·
Registered
Joined
·
567 Posts
Discussion Starter #28
Thanks to everyone for the suggestions and advice. I pulled the Napa 1069 filter off today and regretfully, cut the top off with some snips. Currently icing my tennis elbow lol

At any rate, I have a few pictures of the filter. What the heck am I looking for exactly? Kind of hard for me to tell if these are little metal shards or just part of the filter that is wet with oil. I also picked up a oil pressure gauge and will bypass the electric one to see what kind of pressure I have. Still need to adjust valves before I can fire it up.

Any thoughts on the filter?

IMG_4657 by chevelle69ss, on Flickr

IMG_4658 by chevelle69ss, on Flickr

IMG_4660 by chevelle69ss, on Flickr
 

·
Super Moderator
Joined
·
12,634 Posts
You need to cut the paper part out so you can spread it open. Kind of hard to describe the process but I use a box cutter and go all the way around both ends and then pull the paper out. What did the oil in the bottom of the filter can look like ?

I dont see anything hateful from your picture but its hard to tell. The oil does look awful dark for as little running time as it has. But again, thats really hard to tell from a picture.
 

·
Premium Member
Joined
·
4,913 Posts
You are looking for anything that looks like small metallic grains. That could be cast iron, coatings from bearing shells, particles of worn Lifters. If it's there, it came Crome somewhere. Take your cleaned drain pluc magnet and run it all over the filter paper. See what appears.
 

·
Registered
Joined
·
567 Posts
Discussion Starter #31
I'll cut the filter open later tonight and try the magnet in the pan. The first thing I noticed was how dark the oil was, especially for only 800 miles.

At first glance, the pan that I dumped the filter into didn't look bad. There weren't any noticeable shavings, just super dark. Seemed to have a gasoline smell compared to my other cars, but I'm sure it runs rich 99% of the time being that it's a street car with a dominator.
 

·
Registered
Joined
·
567 Posts
Discussion Starter #33
I will go with oil pump pick up came off, not tack welded on well. Happened to me on a new build with the same symptoms.
I did have the pickup tack welded on, but decided to give it a check since i had the oil drained anyhow. I used a coat hanger and could feel the pickup, it would move a bit when I hit it with the hanger, you could kind of hear it move, definitely seemed to have a little play. Is this normal if the pickup is tack welded on? By no means could I push it and move it around in the pan. It was hard to get the hanger under the pickup, because of the angle and tight clearance, but pretty sure I was able to get it completely under the pickup at one point and slide it around.

Next step is to put fresh oil in it, adjust valves, and fire it up with a oil pressure gauge on. Unless I have a faulty gauge or somehow the oil/filter was creating oil pressure issues, I have a feeling the motor is coming out.
 

·
Registered
Joined
·
11,270 Posts
I did have the pickup tack welded on, but decided to give it a check since i had the oil drained anyhow. I used a coat hanger and could feel the pickup, it would move a bit when I hit it with the hanger, you could kind of hear it move, definitely seemed to have a little play. Is this normal if the pickup is tack welded on? By no means could I push it and move it around in the pan. It was hard to get the hanger under the pickup, because of the angle and tight clearance, but pretty sure I was able to get it completely under the pickup at one point and slide it around.

Next step is to put fresh oil in it, adjust valves, and fire it up with a oil pressure gauge on. Unless I have a faulty gauge or somehow the oil/filter was creating oil pressure issues, I have a feeling the motor is coming out.
No the pick up should not move at all. Can you get the pan off in the car? I know its a pain in the butt, but I think your issue is isolated to the oil pump.
 

·
Premium Member
Joined
·
1,183 Posts
I agree with Ray - the pickup should have no play. If you're sure the pickup moved even just a little, I'd get that sorted first. Not sure why the pickup moved unless its not the right one for the pump/pan, wasn't fully installed, or if it was bottomed-out on the pan. If you have a hoist, you could remove the engine mounts and pick it up 2-3" from the front to get the pan off.
 

·
Premium Member
Joined
·
1,183 Posts
If you could get one of those camera/probe gizmos, you could probably see if its moving through the drain plug hole.
 

·
Premium Member
Joined
·
6,955 Posts
This is a lot of work and drama to go through based on a reading from (if I understand correctly) the notoriously inaccurate stock electric oil pressure gauge.
 

·
Premium Member
Joined
·
2,928 Posts
Since you did have the pickup tack welded and you feel some movement, chances are good the pump is loose which I think Ray alluded to.
 

·
Registered
Joined
·
567 Posts
Discussion Starter #40
Since you did have the pickup tack welded and you feel some movement, chances are good the pump is loose which I think Ray alluded to.
As little Ralphie would say, FUUUUUUUUUUUUUUUUUUUUDGE :)

Is it a fairly common thing for a pump to come loose, or just as common as anything coming loose?

Looks like i'll be in the market for an engine lift. I had a growing leak in the trans, so I might try to pull them both out in one shot and get both repairs done. With my copious amounts of free time, should have her back on the road by 2020!
 
21 - 40 of 59 Posts
Top