Engine expert needed- non Opel

[Jeff Pozorski]

Sorry for posting a non-Opel engine question but I am desperate and figure someone in our group will know the answer. I recently received for free a 1996 Dodge B250 van with the 3.9 litre v6 engine. Previous owner just had a new oil pump installed due to low oil pressure (guage read zero and idiot light came on). That problem is now back. Oil pressure is fine when the engine is cold but as soon as it warms up the oil pressure drops to zero and idiot light comes on. Guages are correct as the lifters begin to tick loudly if I let the engine continue to run. When I shut the engine off and let it sit for a minute and restart I do get oil pressure again for a few minutes before losing it. Oil was just changed and is filled to the proper level. Could the oil pump be loose? Or is the engine trash? Previous owner was my son-in-law who purchased a front wheel drive minivan for his work and donated the Dodge to me for my business. I am open to any and all ideas.
Thanks!

[hrcollinsjr]

How many miles are on the vehicle? I have 225,000 on a '96 5.9 and still have good oil pressure. My '96 5.2 has even better pressure with only 110,000 miles. The first one was run on synthetic oil and the second on regular oil.

Harold

[Jeff Pozorski]

I knew I forgot something - 75,000 miles. Engine sounds great when the oil pressure is up.

[okiejohn]

pull the pan and take off the oil pickup tube it might be partialy clogged inside and restricting oil flow to the pump

[ourcrew]

Could it be something in the oil pan that gets sucked up and covers the oil pickup tube. This might explain why when cold it works and that it works after shutting it off for a minute after it happens. When cold it (what ever it is) is in the bottom of the pan not blocking pickup tube, once oil warms up it gets loosened from the pan and blocks the pickup tube.When warm it is floating around. When you shut off the sucktion on the pickup tube disappears and then the oil in tube flows back and puts it(the thing whatever it is) back to floating in the oil. Which finally gets sucked up again sometime later after you restart it.

[hrcollinsjr]

Originally Posted by ourcrew Could it be something in the oil pan that gets sucked up and covers the oil pickup tube.

The pump has already been replaced because of low oil pressure. I would think that who ever installed it, would have made sure the pan was clear of anything that could be a problem. I'm not on my home computer but there is a Dodge group that you might check out. They don't have as good a search feature as this group does though. Until recently I've only owned Dodge V-8's and Opel's. Forgot I had one minivan, sold it with 250,000 miles and good oil pressure.


This probably doesn't have any relevance but what weight oil and brand of filter do you use?

Harold

[ourcrew]

Do they clean and wipe out the oil pan when they change the oil pump. I would but I am not sure a mechanic would bother. Not to knock mechanics just not something normally done.

[2 Fast 4 U]

Originally Posted by ourcrew Do they clean and wipe out the oil pan when they change the oil pump. I would but I am not sure a mechanic would bother. Not to knock mechanics just not something normally done.

As you said here above, if you want something done right do it your self [if you can!!]

[hrcollinsjr]

They are going to drain the oil and drop the pan. It would be obvious if there was something floating around in there. Heck, it would probably cause problems with it draining.

Can you easily get to the distributor and pull it? I'm wondering if there is a problem with the pump drive even though it won't explain decent oil pressure until the engine warms up. There is an intermediate shaft between the distributor and the pump. The pump is driven by a shaft being driven off a gear at the rear of the camshaft. The distributor has a straight blade that sits in the top of the oil pump intermediate shaft.

How much oil are you putting in the engine? I've known of the wrong dipstick being installed. I filled to the full level on an old Ramcharger I owned and it always seemed to use a quart but never went below that as long as the engine was in good order. The owners manual called for 5 quarts the dipstick read full at 6 quarts.

Are there any knocking sounds from the engine that might indicate excessive clearance anywhere?

Harold

[opelnut10]

My money is on the pickup tube/screen> When they changed the pump if they reused the old pickup tube and screen it could be partly blocked on loose. If the tube is loose where it goes into the pump it will loose suction by developing an air/oil pocket in the tube. When you shut it off it drops the air bubble and will suck oil when re-started until it develops the air bubble again.

[ddoyle]

Hi Jeff,
These engines have a lot of issues with oil psi and noise. The pick up is very small, wont take much to plug it. Overtourqing the intake manif can crack oil galleries. There are TSB's on the distb drive and bushing and another for an updated timing chain and tensioner. I would also recomend the MOPAR oil filter on this engine. Oil sludging is a very common problem with these motors, sometimes helped by running a good engine cleaner thru and 3K oil changes. I have also heard of spun and worn cam bearings, exploded hyd lifters. well let us know what you find out.

Dan

[Jeff Pozorski]

Thanks to all for your your replies (except you Opleman70). I will pull the pan and check for a blockage in the oil pickup tube. The place that replaced the oil pump was a CarX dealer. I was not impressed with what they did. When my son-in-law gave me the van I checked the oil and it was overfilled by 4 quarts! I drained out the excess and the dipstick read full, before that it was well above the full line. Engine sounds great, no knocking of any type at all. I will post again once I get the pan off and see what I have or don't have.