eratic oil pressure 5.2 ltr helppp!!!

[vip]

I Have A 2001 Ram 1500 With The 318 5.2 Engine , Oil Pressure Jumps From 40 To 0 For No Apperant Reason, And Then Lifters Began To Tick. Turn Off Truck And Recrank Oil Pressure Returns To 40 Lbs, Rev Up Engine To 2000 Rpm Or Better And Pressure Goes To 0 Instantly. I Have Replaced Sending Unit, Replaced Oil Pump And Pickup, Changed Oil And Filter Using Dodge Filter, Removed Valve Covers And Intake Cleaned Out All Sludge, Tried 3 Differentweights Of Oil, Cleaned Oil Passageas, Inspected Oilpump Drive Shaft, Pulled Rear Main Cap And Inspected Bearing , Looked Good, Changed Oil And Filter 3 Times , Engine Is Very Clean. Engine Never Has Low Oil Pressure Either 0 Or 40 Lbs Never 10 Or 20. I Have Heard Others Describe This But Never Heard The Answer . Truck Has 70,000 Miles ,runs And Sounds Perfect When Oil Pressure Is At40. It Can Idle At 40 Lbs Hot, Which Leads Me To Believe Bearing Clearances Are Fine. Help!

[amac209]

okay i'm gonna guess at this one!!! you said you cleaned the oil passages but the only thing i can think of that would cause something like this is oil pooling up in the valve covers untill the pan goes dry. did you clean all the drain back passages?? if this is the problem using heavier oil will just add to the problem. try adding some seafoam or atf to your oil to clean things out. good luck with this

[vip]

thanks for your reply , but have allready removed valve covers and cleaned all passages .

[desertmike1]

You have an interisting problem!
Is your oil pressure relief valve built into the pump it-self?

You mentioned inspecting the oil pump drive shaft, whats on the other end of it?

This sounds like,
(a) pump stops rotating
(b) oil dumping do to a bad releaving device

The fact that your lifters tap sure sounds like loss of pressure.

I don't think you have a block any-were.
When you increase RPM the pump puts higher loads on it's drive, and begins dumping a much higher volume of oil back into the pan.

Good luck with this one,

-Mike

[Michael Foote]

I have an 88 Dodge with 245,000 and never had that problem until I was trying to mess around under the dash. Maybe I messed up the dash gauge I don't know but what I'm going to do about it is to install an old style pressure gauge like you can buy at a parts store. That way I'm not depending on electronics but on actual pressure from the engine. If you still have the problem the only thing I would think is the oil pump is going bad or partially clogged pump screen in the pan. BUT I'm not a mechanic and I was just offering an opinion and I'm going to keep watching this site in case someone that knows has the answer.

[donwon37]

Under the intake is the plenum pan,the gasket breaks on these and causes erratic oil pressure fluctuations.This will also cause the engine to consume oil by pulling it through the pcv valve.You may notice just a small amount of smoking when you first start the vehicle.

[BleedDodge]

That's no plenum gasket problem. He was hearing lifters.

That's the EXACT same thing that happened to me last summer. Oil pressure would read nothing and then over center, back and forth. Finally it would just read nothing, and wait a little bit and then you'd hear the lifters. I had someone else take the truck for a ride and I noticed it smoked out the pipes on accelleration. Barely ran it like that, and took the oilpan off to have a look. There was like two inches of sludge in the pan, the pickup screen was clogged, and the mains were blue from heat. Under the valve covers the cake was so thick that it looked like a cast copy of the valvetrain. I'm serious. I couldn't believe it. I had to put another motor in it.

That engine is fucked I'm telling you.

[donwon37]

[quote=BleedDodge]That's no plenum gasket problem. He was hearing lifters.

That's the EXACT same thing that happened to me last summer. Oil pressure would read nothing and then over center, back and forth. Finally it would just read nothing, and wait a little bit and then you'd hear the lifters. I had someone else take the truck for a ride and I noticed it smoked out the pipes on accelleration. Barely ran it like that, and took the oilpan off to have a look. There was like two inches of sludge in the pan, the pickup screen was clogged, and the mains were blue from heat. Under the valve covers the cake was so thick that it looked like a cast copy of the valvetrain. I'm serious. I couldn't believe it. I had to put another motor in it.

That engine is fucked I'm telling you.[/quote
This is what was wrong with mine..........I'm just saying that the Dodge engine especially the 318 was notorious for the plenum gasket faulty.It will cause the lifters to rattle,to consume oil pulling it through the pcv valve into the intake.If it's gone wrong,it's happened to mine.

[BleedDodge]

The plenum gasket has been shot on my other truck for about 3 years now. It does everything you mentioned, and that is true I know.

This guy said he had sludge though, so the motor is finished.

[TurboDuck]

I've seen worked on all (3) mentioned problems. Sludge, bad plenum gasket, and faulty sending unit. This one sounds like sludge.

I see where you've replaced the pump and pickup, was this before or after you cleaned out the top end?

You may have re-created your original problem if you replaced the oil pump, then cleaned out the top end. You may have washed the gunk down into the new pump / pickup. I had a similar situation with an older Chrysler. The owner used some of that engine cleanout stuff in it, which washed all the junk down into the pan, which plugged up the oil pump pickup.

But, the lifter click noise, sounds like an oil loss problem. The plenum problem will cause a pinging under load, not a "zero" oil pressure problem.

Good luck.

[fredjacksonsan]

BEfore you give up on it (since it runs ok with pressure) try using Auto-RX. It is supposedly very good at cleaning up sludged engines gradually. You can read about it here:

http://www.auto-rx.com/

Bit of a commercial, but good info. There is discussion about Auto-RX (ARX) at this site:

www.bobistheoilguy.com

BleedDodge may very well be right that your engine is dead, but buying a few bottles of ARX might save you thousands in rebuild costs. It's worth a try anyway.

[fredjacksonsan]

Oh yeah, and dropping the pan, removing any sludge and cleaning/replacing the pickup screen will go a long way to getting things back to normal; if, that is, the engine can be saved. Good luck with it.

[tony36]

I had the exact same thing happen to me, my problem was I was 1/2 a quart over full. For whatever reason my gauge would drop to 0 , and it would eventually start tickking. Once I dropped the extra oil I never had that problem again.

[BleedDodge]

Originally Posted by fredjacksonsan

Oh yeah, and dropping the pan, removing any sludge and cleaning/replacing the pickup screen will go a long way to getting things back to normal; if, that is, the engine can be saved.

If all eight bearings aren't smoked already...

[fredjacksonsan]

Originally Posted by BleedDodge

If all eight bearings aren't smoked already...

True....and Tony36's idea is definitely worth a look. IF....