1967 CJ5 with 225 and no oil pressure.

I began looking further into this Jeep trying to decide if I want it or not.
The distributor had been pulled and was laying on the intake manifold. I found out that they could not get any oil pressure and gave up.
Checked the oil level and then spun the oil pump drive with an cordless drill set up. Nothing.
The owner said they rebuilt the oil pump and it looks like they did. I dropped the oil pan to check the pickup tube and screen. Other than some dirt it in the pan it looked alright.

Do these oil pumps need to be manually primed before being installed?
Could they have installed the rebuild kit wrong on the pump?

Just looking for some ideas to chase this thing down.
I plan to do a compression check later today.

 

The pumps need to be packed with pretoroleum jelly for priming. I would also check the oil pump gasket to make sure you have a good seal.

 

Mmm. Packing with vaseline is done instead of priming with a drill, AFAIK. The vaseline fills the cavity in the pump and makes it pick up oil right away. Priming with a drill gives the pump some time to purge the air in the cavity, so that the cavity is filled with oil at start-up. Same effect. AFAIK the drill approach is considered superior.

Looks like they did something wrong in their oil pump rebuild. However, if they felt the need to rebuild the oil pump, there must have been little oil pressure to begin with. I suspect if you fix the immediate problem, you will find something else wrong.

I'm not the expert with the Buicks...

Are you the '68 Dodge Coronet R/T from AutoBody101.com?

 

You either do jelly or prime AFAIK.

When I did my oil pump on my Dauntless, I did the drill priming. Really easy to do if you can rig something long enough. Took about a minute before I got the pump to prime and I had immediate pressure at start up.

The 225 doesn't have crazy oil pressure at start up. If you were spinning and not getting oil I think the rebuild might have been done wrong.

 

Not to hijack this thread, but is there any other way to ensure the oil pump is working other than the oil pressure gauge?

 

Maybe seeing oil squirting out somewhere, like from the rocker arms?

Or, if you really have zero oil pressure the lifters will clatter like 12 little hammers inside the engine. It will be loud and noticeable.

 

Thank you timgr, as usual, very knowledgable and informative.
I hate to even start it up now and causing possibly any more damage. I've started it up several times and even drove it up and down the driveway, never really paying attention to the oil pressure. I just figured it was a cheap gauge that I would replace later.
Didn't hear any loud noises or hammering going on, at least not yet. Hope the damage isn't already done.

 

With two gears in the pump , there really is hardly a way to screw that up...........perhaps the oil relief spring & spacers could be stacked incorrectly? But,

What most folks don't understand about Buick oiling when they have low oil pressure to start with and go about replacing gears or adding a higher tension relief spring is that the most Important part in making oil pressure in one of these Buick motors lies in the "Front Aluminum Cover" The cavity that the gears ride in can be over sized right from the factory and is subject to wear. The walls of the cavity can get scored after a few errant scraps run between the gears and wall cavity and last the bottom of the cavity can also get scored.............If either the cavity is a little large , has scores in either the base or walls the clearance between the gears and cavity goes away and oil will leak internally around those area's and not make much pressure. As others have said use some petro Jelly to get it primed..........or sometimes a 50-60 weight oil may help.

 

I noticed Oz has a post about his 225. I guess I'll do what was suggested and pull off the valve
covers, start the engine and see if I get any flow or squirting of oil.

 

Also when priming with a drill motor, you have to rotate the oil pump shaft in a clock wise direction. It will not pump oil in reverse (CCW) as looking down into the hole.

 

I've seen this same issue after "rebuilding" the oil pump before. The problem was the over-pressure relief valve was not seated. They used too short of spring, and the plunger was not resting on the seat so all oil pumped was instantly bypassed/dumped.
The spring is held by the hex plug on the side of the lower part of the pump body. This same spring is what actually controls max oil pressure, and can be shimmed for higher pressure output, though this is usually not needed for our 225s. I also play with the Buick 215/Rover 3.5 that is a close cousin, but with high rpm use (up to 7000 rpm), the oil pressure must be increased to deal with centrifugal force at high revs. The V8 uses the same timing cover/oil pump as the Dauntless.
- Donny

 

"Shimmed for higher pressure output" please explain.

Does this hex plug need adjusting?

 

Well took off the valve cover, started engine, and didn't see any oil squirting or even oozing out from any where. I did notice a build up of oil in the corners of the valve area that wasn't there before, so sometime while it was running oil found it's way there, but I'm sure I should've seen active oil flow.

 

On Buick and AMC engines with the oil pump remote mounted in the timing cover ALWAYS pack the cavity with petroleum jelly. It keeps the pump lubricated and creates the necessary suction to build oil pressure. Waaaayyyy too many times have I seen damage caused by people not priming these engines properly. Two gears sucking air cannot reliably suck engine oil from the pan, through the pickup, and into the oil pump cavity.

 

Yes.

 

I tried it both ways. I had the valve cover off and was watching for any sign of oil reaching the shaft but nothing.

 

I may just rebuild the oil pump myself as the kits are fairly inexpensive and then I will know it is done right.
Never heard of packing the pump with petroleum jelly before but confess I mainly deal with Mopars and Fords.
I restored a 65 Buick Convertible that had this same engine in it but the owner paid a shop to build the motor. The motor wouldn't quit spewing blue smoke so I had to do some investigating. They had installed the rocker arm shafts backwards, so cleaned them up and reinstalled correctly. Smoke went away as soon as the oil burned out of the exhaust system. Sometimes its the simple things that get overlooked.

 

I have enjoyed reading your posts there. Very informative. I remember you writing that you media blasted the firewall of your Dodge with one of those hand-held units from TP Tools or Harbor Freight or somewhere. No message, just one of your posts that I particularly remember for some reason.

Good luck with your Jeep. We like them here.

The Buick odd-fire 225 engines have a lopey idle that's fun and characteristic - like a Harley. Once you get them running ... And in the day, they were a particularly good fit to the short early CJ-5 engine compartment.

 

Under the hex plug, there is a spring and an inverted "cup" plunger the spring fits in. The opposite end of the cup seats on the pump housing, making the over-pressure seat, which controls max oil pressure.
You can either replace the spring with a longer or stronger spring, or use small washers the diameter of the spring bore stacked under the plug to exert more pressure on the plunger. The washers are what I referred to as "shims".
High oil pressure (more than 50 psi) is not a good thing for our Dauntless engines. If they run between 35 to 45 psi at road speed, all is good.
-Donny

 

Thank you for that explanation Donny!