5.7 hemi oil pressure issues

A good friend of mine is having issues with his ram truck's 5.7 hemi . Below is his email to me:

my 03 dodge with the 5.7 hemi has had oil pressure issues for a while it would loose pressure but you could turn it off and when you restarted it the pressure would come back up for a while.i could cure this for a while by changing the oil. last week i had a valve spring break on my #2 cylinder. i replace the spring and bent push rod. when i started and drove it it i lost all oil pressure and can not get it to come back up by restarting it.I'm going to replace the oil pump but would like your opinion on this, if there might be something besides the oil pump causing the problem. I've built lots of rb b and a motors but this is the first time I've worked on the new hemi motor.


Anyone have any idea's to toss his way?


Thank you

Allen

Sounds like a plugged oil pick up screen. If it really is losing pressure as gauge indicates, I'd first pull pan to look for crud. If the screen is plugged, I'd clean it out and throw pan back on. I don't know if the new hemi has crank snout driven pump or not. (harder to change then)

Only oil pressure problems I've seen have been oil pump relief valves sticking, bad oil filter, and sludge

Thanks.

Hoping someone has seen "other" issues with oil pressure and the 5.7 hemi, but also hoping the oil pump changeout fizes the problems. I have 110k on my 05 QC hemi and sans a cracked exhaust manifold mine has been very reliable. My son borrowed it Christmas eve, and said she has a lot of gnuts compared to his 99 chevy 350 4x4...lol

Thank you

Allen

His description sounds like it lost prime/somehow got an air pocket trapped inside. He might want to try replacing the oil filter and completely filling the new filter with oil (may take over an hour for it to soak into the element) to see if that makes any difference.

He also might want to try loosening the filter and/or loosening the oil pressure sender, starting it, allowing it to make a mess for a second and then trying again. The idea is to purge air.

If none of that gets it, then....

Don't blame him a bit for wanting to put a pump in it, but they aren't ridiculously prone to failure.

If he's set on doing the pump, I'd probably shotgun it/do the pump along with the stuff below to make sure it isn't sucking or pushing air.

There is an O ring between the oil filter adapter and the block that might be slowly failing/might be twisted in the groove or something (Actually I'd probably do that first since it's the least invasive, and should take under and hour to replace).

Also the pickup tube has a o ring that can potentially fail. The pickup tube mounting flange is, if I remember right, swedged on (not welded), and I would want to make sure the whole pickup tube is air tight. I would also check out the pickup to pan clearance.

Broken spring means the lifter could have been launched upward enough to expose the oil passage to air. Hopefully the lifter retaining yoke is still in good shape...unfortunately the only way to inspect it is to remove that head. It's probably fine, they are not known to break even though they're made of plastic.

About the only good news in the whole deal is...once everything around the radiator + the upper core support is removed, it makes a fairly comfortable place to sit/stand and work on it. Having done a couple top end + cam + header jobs I can say from experience....the trucks are MUCH easier to work on than the same engine in a car chassis.

The pump wraps around the crankshaft in the front, btw.

Found this TSB related to cold temp's, but tells me there is a new pick-up available. I would either put a gauge on to ck pressure or at least a new sender unit(they go bad alot) SUBJECT:
Low Engine Oil Pressure At Start Up In Temperatures below Freezing
OVERVIEW:
This bulletin involves replacing the engine oil pump pick up tube.
MODELS:
2003 (DR) Ram Truck
NOTE: This Bulletin Applies To Vehicles Equipped With 5.7L Engines.
SYMPTOM/CONDITION:
Some customers may intermittently experience an oil pressure gauge indicating
low oil pressure at start up in below freezing temperatures.
DIAGNOSIS:
If customers indicate that the condition is present, perform the Repair Procedure.
PARTS REQUIRED:
Qty. Part No. Description
1 53021522AD Oil Pump Pick Up Tube
SPECIAL TOOLS/EQUIPMENT REQUIRED:
8534 Engine Support Tool
REPAIR PROCEDURE:
1. Using the procedures outlined in the 2003 Ram Truck Service Manual, publication number
81-370-03059, section 9 page 218, Remove thew engine oil pump and pick up tube.
2. Check the oil pressure relief valve for any irregularities that could cause
the valve to stick open. Repair as necessary
3. Install the new pick up tube, p/n 53021522AD.
POLICY

thanks guys and thanks Allen.I went a head and joined you site looks like a good place. I think i have been having problems with the pressure relief valve for the last yr.when i changed the exhaust valve spring and push rod i noticed that i had some sludge in the heads and on the exhaust rockers.Since I'll have to pull the pan anyways to check the pick up I'm going to go a head and put a new oil pump on. and hopefully that will be the end of my problems.

Make sure a lifter hasn't popped out. With the bent push rod and lifter problem it is a possabilty

i believe the lifter is fine i started it without the valve cover and all the rocker arms appear to be opening and closing equally

pick up was clogged with sludge. but what worries me now is that there was bearing material in the pan

Good job finding it. Bearings aren't any worse to do than an older motor. If it was THAT nasty and plugged up I'd advise pulling the motor and doing a ring and bearing job.

With the sludge in mind...has it ever had the pcv valve changed? Alot of them are running around with the original pcv valve because folks have trouble finding it on the engine + it's about a $25 dollar part.

i change it last week when i first noticed the miss. pvc hose was deteriorated and i thought that might be the cause of the miss at first

Does this 5.7 have the cylinder dropping feature to get better mileage, as in the luxury cars? I don't believe anything was mentioned as to what type of vehicle this engine was in. I could see that solenoid failing, or the lifter failing or something along those lines.