I am truly stumped here.



Here are the symptoms I have,



When I start up cold, both rockers are oiling, drivers side is better than the passenger.



As it begins to warm up, the passenger side will slow and then eventually quit.



After a few more minutes, the driver's side will do the same.



I have checked for blockage in the galleys up to the rockers. I have cleaned out what I can get into on the top side. The pan has been dropped and the pick up cleaned. Everything put back together and checked.



Any one have any thoughts on possible causes? It has been suggested that I have a bad oil pump, which I guess is possible. I have also heard that bad cam bearings can do this also. But which is more likely with these symptoms? I am not entirely mechanically inept, but this has me chasing my tail.

http://hillbillyheretic.wordpress.com

How much oil pressure do you have once the engine warms up? Do you have a gauge or a light?

Kenneth

Fredricksburg, Texas

I’m with Kenneth as it sounds like very low oil pressure on the engine which could be as simple as the oil pump or as complicated in being bearing and journal wear.  I’ll suggest putting a pressure gauge that’s known to be accurate and taking readings both cold and hot.  A heavier weight oil may also help but is only going to be a short term fix until the root problem is remedied.

Lorena, Texas (South of Waco)

I had a bsaic sunpro guage in the truck for a bit, but the line recently broke. But before the plastic line broke, it was showing about 30lbs hot. I have a couple of other guages that I will try and fit into the port to see what they say tomorrow.



But what is considered an acceptable range?

http://hillbillyheretic.wordpress.com

15-20 psi hot and idling should be the low side of sufficient.  If you go to a fast idle for a minute or so, does the oil flow to the heads resume?

Lorena, Texas (South of Waco)

You might consider replacing that oil line with the copper line.I dont know why they even supply plastic with those gauge kits except maybe its cheap.I would agree that it sounds like low oil pressure.

  

Unfortunately, no. Once they quit, it is done. I would guess about 5-10 minutes to lose all pressure to the passenger side, and after that the flow gets slower and slower on the driver side. Maybe another 5 minutes or so for the flow to become negligible to consider good.



The pressure gauge was already on the truck when inherited it. I didn't have any spare line, so I just blocked it off using a shallow plug. But I have two other direct fitting PSI gauges I can use to verify the pressure.

http://hillbillyheretic.wordpress.com

OK, I just finished testing again.



I connected to a port towards the front of the drivers side of the block. Tell me if I picked a bad area to connect.



But initial start up, I was showing about 40PSI, after about 5 minutes it dropped down to 30PSI. Everything is still oiling at this point.



But the pressure keeps going down. At 20PSI, I lose the passenger side rockers, then it drops to 10PSI and I lose the drivers side also.



If I rev up, I get back to 30PSI, but no change up top.



Now I have heard of cars oiling well with 10-20, but I am not sure how a Yblock will do this low. Are these signs of a bad oil pump? Or could it be something else?



Sadly enough, I am stuck only with a 1962 Chilton's auto repair manual that does not get very specific with the Y, so I have to ask what may be a lot of dumb questions.

http://hillbillyheretic.wordpress.com

Hi, oil pressure situations are fairly basic and dont differ alot between models, for my 2 cents worth, i would be guessing a pretty worn engine and maybe a combination of worn main and cam bearings, releasing the pressure once warmed up and oil thins out more, and just cant get to rockers then? just a guess of symptons. Glad to hear of fix later on. regards bill.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

I am thinking that it is just a tired motor myself. I can't fathom how an oil pump would start with such nice numbers and drop so quickly, unless there is high wear elsewhere. And honestly, I don't really know the history of the truck. I just know what the last owner did with it. And that was drive the wheels off of it.



I am going to be doing a compression test here today just to give myself a better idea on the condition of the motor in general. I think it is safe to assume that if the motor is showing low compression numbers or numbers with a lot of variance, I may be looking at having to go through the whole thing.



If that is the case, I am going to have to do some serious thinking. Money is limited and this is more or less my main driver. The though of having to pull the motor for a rebuild may color my final decision.

http://hillbillyheretic.wordpress.com