318 dodge oil pressure

i have a 1972 dodge 318 engine in my 32 ford. it has a high pressure oil pump and a remote oil filter. i just changed the oil and filter and thought it would be good to blow air through the lines leading to the filter to get the old oil out. now i have no oil pressure [i had 60 pounds before i drained the oil ] is there any possible cause for this besides pulling the pan and checking for a stuck oil pump relief valve? jim lose

You lost your prime. Try taking out the distributor and driving the oil pump with a drill until pressure comes up. If you do not know how to do this you might ask a mechanic.

Try filling the oil filter with oil.

You lost your prime. Try taking out the distributor and driving the oil pump with a drill until pressure comes up. If you do not know how to do this you might ask a mechanic.

You MUST do this if you drained the oil lines.

i seem to be getting oil because the filter was full when i took it off and checked. i ran the engine longer than i wanted to and still no pressure. i had this problem on a packard once and had to put a restriction fitting in the oil filter line. do some oil filters have a restriction?

If you have oil in the filter, then I gotta agree with the others, you need to prime the oil pump.

You'll need a pump primer shaft (under $10). Jegs has them.

Pull the distributor and look straight down into the hole. You'll see the top of the oil pump. The primer shaft goes into that. Attach an electric drill to the other end of the primer and spin it until there's oil pressure showing on the gauge.

Put the distributor back in, retime and enjoy.

If the oil filter was full, and you did not fill it, then the oil pump must be working. Put the filter back on (fill it with oil first) and start the engine, pressure should come up in a minute.

318s are tough. You probably did not do any permanent damage.

Sometimes things can be a lot less complicated than one thinks. In this case have you checked the electrical connection to the oil pressure switch/sensor to make sure it hasn't accidentally come loose. Even the device itself could have just decided to give it up. Just because it worked before the engine was shut down doesn't necessarily mean it does now.

Jim

I think it just took a long, long time to build up oil pressure. If you don't fill the oil filter and you are concentrating on the light or gauge it can seem to take a long time for the pressure to come up. With the pump and oil galleries empty it would take even longer. But if the oil filter was partly full the pump must be working and the galleries must be full so the pressure would come up in a minute or less.

Before you go to all the trouble & headache of pulling-out your distributor and using an electric drill and shaft to spin your oil pump~~~

Use the car's starter motor to prime the oil pump, filter, and oil lines.

For some people pulling -out the distributor can open a whole new series of troubles !

Just disconnect your ignition coil battery + terminal wire or center high voltage lead and spin the engine with the car's starter.

Only run the starter for 20-to-30 seconds at one time and then allow your strter motor to cool in between runnings for 10 min.

To help spin the engine faster you can pull-out your spark plugs so that the engine will revolve faster !

Good Luck !

Before you go to all the trouble & headache of pulling-out your distributor and using an electric drill and shaft to spin your oil pump~~~

Use the car's starter motor to prime the oil pump, filter, and oil lines.

For some people pulling -out the distributor can open a whole new series of troubles !

Just disconnect your ignition coil battery + terminal wire or center high voltage lead and spin the engine with the car's starter.

Only run the starter for 20-to-30 seconds at one time and then allow your strter motor to cool in between runnings for 10 min.

To help spin the engine faster you can pull-out your spark plugs so that the engine will revolve faster !

Good Luck !

If you are going to take out the spark plugs and "spin" the motor, be sure to disconnect the fuel line or you will start a fire with your starter. I speak from experience.

Been thinking on this a bit and went back to the original post where it is revealed that compressed air was blown back into the block. This may be a reach but I suspect removal of the oil pressure switch/sensor might reveal the orifice at it's base is now full of so much crap it couldn't possibly work.

Jim

more on the great oil pressure mystery. yesterday i went all over town trying to find a oil pump primer rod or at least a 5/16 hex rod. no luck so i made one. today i spun the oil pumpfor a longtime with no results still no oil pressure. the pump turns hard so i probably screwed it up, tomorrow the pan comes off fpr a pump check. never change oil on a 318 dodge, i have been a mechanic for all most 60 years and never ran into any thing like this. j lose

Well now you know not to blow air into an oiling system. If you have been a mechanic for almost 60 years and this is the first mistake you made, you are doing great. I made worse mistakes my first week. Ha ha ha good luck.

PS is there lots of oil in the crankcase? Tossing in a couple extra quarts might help flood the pump and get it started pumping oil. Easier than taking the pan off anyway.

Been thinking on this a bit and went back to the original post where it is revealed that compressed air was blown back into the block. This may be a reach but I suspect removal of the oil pressure switch/sensor might reveal the orifice at it's base is now full of so much crap it couldn't possibly work.

Jim

I tend to agree on this one.

If the pump turns hard (and you are turning it in the correct direction) you may have oil pressure. I would pull the guage sender or maybe a valve cover and be sure before pulling the pan.

If you pull a valve cover make sure to turn the engine over some.

Rustys idea of over filling sounds like a good idea.

We had a Graymarine V8 V8C-238 boat engine (327 AMC based) that was installed with the flywheel foreward and the Borg-Warner velvet drive transmission fastened to the front timing case area.

After long periods on non use the oil pump, which was now up front and out of the oil pan level with an unusually long pick-up tube. This set-up woud often loose it's pump prime.

We found that by removing the oil pressure sender we were able to force oil into the dry pump with a hand pressure or electric drill style oil change pump !

If you pump is indeed stiff I suspect it is building up pressure~~~

You may have damaged your oil pressure sender.

Replace it first before pulling your oil pan .

If not~~~

you may have popped-open the pump's pressure relief valve and it is now broken or is stuck !

Some valves have a ball bearing style valve & seat.

Others have a fiber disc style valve !

yes yes yes jim edwards was right about crud pluging the 1/8 inch oil line to the gage. i feel like an idiot because my wife suggested gage trouble the first thing and i said no way because it worked fine minutes ago. i didnt think about the chance of crud being in the oil line when i blew it out. thanks to every one who sent sugustions to my problem. i might use your ideas on a future problem. larry

yes yes yes jim edwards was right about crud pluging the 1/8 inch oil line to the gage. i feel like an idiot because my wife suggested gage trouble the first thing and i said no way because it worked fine minutes ago. i didnt think about the chance of crud being in the oil line when i blew it out. thanks to every one who sent sugustions to my problem. i might use your ideas on a future problem. larry

Hey Larry, no reason to feel like an idiot over this. If there were to be a survey of everyone who ever turned a wrench on an engine to see who deserved recognition for being an idiot the manufacturer of "Dunce Caps" would be unable to keep up with demand for years. Some of us might actually be entitled to multiple "Dunce Caps", or "Dunce Caps" with Oak Leaf Clusters.

Jim