My son bought a 99 Ram 1500 V-8 and has had it for about 2 years now. Soon after buying it the truck lost oil pressure. Garage changed the oil pump with dealer pump, the tube was plugged up at the time and cleaned out. No problems since, until now.
Water blowing out of exhaust pipe took to garage and they changed out the intake manifold gaskets. Son works at the garage as a helper, he said the intake was caked with gummed up oil. The mechanic plugged all holes and cleaned up the gunk partially with brake fluid cleaner. Also had all new injectors put in and the oil and filter changed.
The truck was started and allowed to run for about 15 minutes and drove around the block several times with no issues.
After work my son drove it home and on the way home he lost the oil pressure several times dropping to zero. Not being a mechanic my guess is some of the gunk worked its way into the engine and plugged either the tube or pump. Any suggestions on what I can do short of taking pump off? Is there anything the mechanic could have done other than plugging it up to cause this like leaving something undone?
Do they make any product that I can pour in the motor to free up this gunk... Thanks for any input

 

try seafoam?

 

If oil pressure drops to zero, you don't wanna run the engine that way...... if it maintains even 10 pounds at idle, you can try the seafoam thing..... Keep in mind, freeing up all that stuff may make the problem worse... not better.

All that said.... it really isn't that much of an ordeal to drop the pan, and clean things out. A new pump from the parts store is only about 25 bucks..... in all reality, if your son has been hanging around with mechanics for a while, he could probably do it himself. He might even be able to talk one of them into helping him some time when the shop isn't open....... He would have a much better idea about that though.....

Before doing anything though, I would check the pressure with a mechanical gauge, and see what is REALLY going on. The electric gauges tend to lie once in while.

 

Definately check with a mechanical gauge. Did it drop to "zero" when the rpms were low, like when at stoplights, or at random times when driving?

 

Dropped to zero while driving, he said it makes a loud alarm type noise when pressure drops to zero. Will have truck towed to shop, drop oil pan, install new pump and clean out the spout tube and hope that cures it.
Thanks

 

with water coming out the exhaust, i'd ask if there was any water in the oil - which creates a chocolate milk mix which is prone to thicken and sludge up. heavy thick sludge can block pickup tubes, pumps, passageways.

...also water can be intake gaskets, head gaskets, cracked heads, etc. compression tests on the cylinders, pressure/leak down tests on the cooling system will confirm that your leaks are fixed or not.

since the oil pressure was fine for awhile, i doubt if anything major was left loose.

pull the dip stick and look at the oil.
if there's nothing wrong with the oil, i'd try to change the oil, maybe fill/drain the crankcase a couple of times with diesel to see if any small gasket pieces might flush out the oil pan drain.

if you wanted to try a flush, use a cheap gunk-brand or similar engine flush. you pour it in, idle 5 minutes, drain it and change filter. the only benefit of this would be removing sludge.

if it remains stopped up, drop the starter and oil pan to service and/or replace the oil pump. this would allow cleanout of larger pieces of trash or gasket material or rag or towel or something that might have fallen into the engine.

 

Check to make sure that the oil pump drive shaft is in good shape.

 

I'd check to make sure they didn't crimp the oil pressure sender unit's cord in between the block and intake manifold causing an intermittent short to ground. If a mechanical gauge checks out good, that's likely the cause.

 

+1 check the oil sending unit, forgot about that, i had this issue on mine expect the water part, my oil would come out and get on my tranny and burn on my mainfolds creating smoke and when took too a shop the first one said i needed a new rear main seal, second told me oil sending unit which then i just changed and problem fixed

 

Mechanic dropped oil pan and screen/pump completely plugged. Put in new pump and screen. Son drove it for 30 minutes and all was fine. Then pressure dropped again, called Auto Zone and they told him to pour some Marvel Mystery oil in it. So he drove it to the parts store oil pressure fine. Drove home after 1/2 can MM oil added and stopped at red light pressure dropped to zero.

He turned off motor at red light after light changed truck would not start, only clicking like starter sound with bad battery/starter.
Pulled to shop they took socket and turned crank said motor not frozen up. They said starter bad so changed it and the battery still nothing.

He thinks it is something electrical saying the starter does not engage the flywheel. You can hear the loud clicking of the starter but motor not attemping to turn over.

any ideas appreciated