1998 Dodge Ram Oil Pressure Lost

greggf34 · 12-06-2008, 06:29 PM

I have a 5.9L with 150K miles. I have oil pressure upon starting, but after running for a few minutes it begins to drop, then goes to 0. Sometimes it comes right back up, other times it will come back if i shut it off and restart. The oil is not low, i checked and then even overfilled it by just a touch. It actually seems to lose pressure when the motor is revved, which is peculiar. Any ideas? Pressure sensor? Clogged oil pump? Other thoughts?

daz75 · 12-06-2008, 09:15 PM

Hi...

Could be the oil pump, or a blockage or slight blockage somewhere, like the pick-up pipe, or a gallery?....Don't know this vehicle, im in u.k...

Id see if it's the oil pump at fault, if not id do an oil change, but do an engine flush in the process.

Sounds like a beast of a car

Daz.

Beohbebewhy · 12-06-2008, 10:22 PM

It may be a faulty oil pressure gauge/sensor. I'd try the easier/less expensive options first, and go from there. It may be a clogged screen on the pickup, too. I'd def do a flush on it too. Even if you have to replace the oil pump, they are relatively low priced and easy to put in, so you're not going to be out a bundle on it.

curious99 · 12-07-2008, 07:45 AM

Dodge trucks have an unusually small opening on the oil pick-up tube.The screen becomes clogged over time from buildup ,especially if the oil changes have been neglected or oil changed after excessively long intervals.The best repair is to replace the pick-up tube,but it can be a difficult procedure to do at home.You might try to dissolve some of the sludge,but if there is still more in the bottom of the pan,it will clog again.Having said those encouraging words,you can try some remedies,like changing the oil and using a thinner oil,say 5w30 over 10w30 ,and substituting 1 qt of automatic transmission for 1 qt of oil to loosen up the sludge.I would'nt reccommend driving more than a few days to a week before changing the oil again.AND ALWAYS REPLACE THE FILTER.AND/or you can try something more radical,like draining the oil,and putting a solvent like 1 gal of kerosene in the oil pan and soaking the pick-up tube over night.Some techs even run the engine with this in the pan,ONLY for about 30 seconds and at idle.If you try any of these,I would reccommend early oil changes about two weeks apart for the next couple oil change intervals,and ALWAYS change the filter.Oil is the life blood of an engine,and always cheaper to change than an engine.Good luck!

**SABL** · 12-07-2008, 08:40 AM

Any major/minor work done on the engine?? Any odd noises when the oil pressure drops?? How clean is the inside of the engine?? Are your spark plugs fouling with oil??

Good advice so far from the members!!

There are many reasons for loss of oil pressure, but from the symptoms it seems that the oil is not returning to the pan quick enough. As soon as the engine loses pressure, shut it down and immediately check the oil level. Better to have an assistant at the ready because you want to do this as quickly as possible. I would remove the dipstick prior to the point of pressure loss, have it wiped clean and ready to measure the oil level as soon as the engine is shut down.

If the level is acceptable then the problem could be with the guage or with the pick-up/pump assembly.

If the oil level is absent or very low, you have a very dirty engine and the oil is not draining from the heads or the "valley" area. If this is what's happening you should also see oil fouling on the sparkplugs at the rear of the engine.

Do some more research and let us know how things are going.
SABL

cjktime · 05-21-2009, 01:27 PM

I have a 1997 Dodge Ram 1500 4x4 5.9 liter which I got sumerged in a nice hole and got water in the engine. I immediately dumped the oil from the engine and replaced it 5 more times. I continued to get low oil pressure so I replaced the oil sending unit. I still got low pressure so I replaced the oil pump and the pick up tube and still read low oil pressure. I purchased a aftermarket guage for oil pressure and it picks up 40 at the start and aroun 5psi after warm up. Funny thing is I have no loss of power and I have no smoke. I heard it could be picking up low pressure from to much clearance between the main bearing and the crank shaft. Does anyone have any thoughts?

12-06-2008, 06:29 PM	#1 (permalink)
greggf34 Registered User Join Date: Dec 2008 Posts: 2 OS: xp	1998 Dodge Ram Oil Pressure Lost I have a 5.9L with 150K miles. I have oil pressure upon starting, but after running for a few minutes it begins to drop, then goes to 0. Sometimes it comes right back up, other times it will come back if i shut it off and restart. The oil is not low, i checked and then even overfilled it by just a touch. It actually seems to lose pressure when the motor is revved, which is peculiar. Any ideas? Pressure sensor? Clogged oil pump? Other thoughts?

12-06-2008, 09:15 PM	#2 (permalink)
daz75 Registered User Join Date: Oct 2008 Location: u.k, yorkshire Posts: 51 OS: xp home sp 3 My System	Re: 1998 Dodge Ram Oil Pressure Lost Hi... Could be the oil pump, or a blockage or slight blockage somewhere, like the pick-up pipe, or a gallery?....Don't know this vehicle, im in u.k... Id see if it's the oil pump at fault, if not id do an oil change, but do an engine flush in the process. Sounds like a beast of a car Daz. __________________ C&G L2 motor vehicle tech & C&G L2/3 autoCAD 2D Qualified

12-06-2008, 10:22 PM	#3 (permalink)
Beohbebewhy Registered User Join Date: Nov 2008 Location: Shreveport, LA & Navarre, FL Posts: 3 OS: Windows Vista Home	Re: 1998 Dodge Ram Oil Pressure Lost It may be a faulty oil pressure gauge/sensor. I'd try the easier/less expensive options first, and go from there. It may be a clogged screen on the pickup, too. I'd def do a flush on it too. Even if you have to replace the oil pump, they are relatively low priced and easy to put in, so you're not going to be out a bundle on it. __________________ BeOhBeBeWhy<br>1999 Ford F-150 4X4,<br>2002 Dodge 1500 Quad Cab,<br>1997 Chevy 1500 4X4 Extended Cab

12-07-2008, 07:45 AM	#4 (permalink)
curious99 Registered User Join Date: Mar 2007 Location: delaware? Posts: 16 OS: xp home	Re: 1998 Dodge Ram Oil Pressure Lost Dodge trucks have an unusually small opening on the oil pick-up tube.The screen becomes clogged over time from buildup ,especially if the oil changes have been neglected or oil changed after excessively long intervals.The best repair is to replace the pick-up tube,but it can be a difficult procedure to do at home.You might try to dissolve some of the sludge,but if there is still more in the bottom of the pan,it will clog again.Having said those encouraging words,you can try some remedies,like changing the oil and using a thinner oil,say 5w30 over 10w30 ,and substituting 1 qt of automatic transmission for 1 qt of oil to loosen up the sludge.I would'nt reccommend driving more than a few days to a week before changing the oil again.AND ALWAYS REPLACE THE FILTER.AND/or you can try something more radical,like draining the oil,and putting a solvent like 1 gal of kerosene in the oil pan and soaking the pick-up tube over night.Some techs even run the engine with this in the pan,ONLY for about 30 seconds and at idle.If you try any of these,I would reccommend early oil changes about two weeks apart for the next couple oil change intervals,and ALWAYS change the filter.Oil is the life blood of an engine,and always cheaper to change than an engine.Good luck!

12-07-2008, 08:40 AM	#5 (permalink)
SABL Moderator Relaxation Room Join Date: Jul 2008 Location: Galena, Ohio Posts: 1,244 OS: WinXP SP3	Re: 1998 Dodge Ram Oil Pressure Lost Any major/minor work done on the engine?? Any odd noises when the oil pressure drops?? How clean is the inside of the engine?? Are your spark plugs fouling with oil?? Good advice so far from the members!! There are many reasons for loss of oil pressure, but from the symptoms it seems that the oil is not returning to the pan quick enough. As soon as the engine loses pressure, shut it down and immediately check the oil level. Better to have an assistant at the ready because you want to do this as quickly as possible. I would remove the dipstick prior to the point of pressure loss, have it wiped clean and ready to measure the oil level as soon as the engine is shut down. If the level is acceptable then the problem could be with the guage or with the pick-up/pump assembly. If the oil level is absent or very low, you have a very dirty engine and the oil is not draining from the heads or the "valley" area. If this is what's happening you should also see oil fouling on the sparkplugs at the rear of the engine. Do some more research and let us know how things are going. SABL

05-21-2009, 01:27 PM	#6 (permalink)
cjktime Registered User Join Date: May 2009 Posts: 1 OS: Vista	Re: 1998 Dodge Ram Oil Pressure Lost I have a 1997 Dodge Ram 1500 4x4 5.9 liter which I got sumerged in a nice hole and got water in the engine. I immediately dumped the oil from the engine and replaced it 5 more times. I continued to get low oil pressure so I replaced the oil sending unit. I still got low pressure so I replaced the oil pump and the pick up tube and still read low oil pressure. I purchased a aftermarket guage for oil pressure and it picks up 40 at the start and aroun 5psi after warm up. Funny thing is I have no loss of power and I have no smoke. I heard it could be picking up low pressure from to much clearance between the main bearing and the crank shaft. Does anyone have any thoughts?