Oil Pressure HELP!

[Firefighter613]

My 1996 Ram 1500 Sport - 5.9 360, after its at operating temp the oil pressure will drop enough for the dummy light to flicker, and sometimes drops all the way - this is only in Reverse, Drive at Idle, when im driving it levels out... Ive notice its mostly only when its under 500 rpm... It doesnt do it in Park, and Nuetral... Its getting aggravating, I just changed the oil to 10w-40, fixed it for a couple weeks...

*Last 3 oil changes
- 10w-30 - Marvals Mystery oil
- 10w-30 - Marvals Mystery Oil
- 10w-40 - RESTORE...


I have a sending unit sitting on the dash, just havent had the time to change it...

My uncle seems to think the oil is too thin, he wants me to change to Valvoline 20w-40 Racing oil (that we run in the race car.)

 

[leadrofthepak]

Oil pressure dropping at low rpms can indicate a clog forming at the pick up on the oil pump.

 

[dodge dude94]

^Pretty much nailed it.

I think your problem might be a combination of low pressure and a bum sending unit. Putting the RESTORE in it didn't help either, that stuff has been known to clog things up on engines, doing more harm than good. Time to drop the pan.

 

[NYCruiser]

You could take a shot and seafoam treat the engine oil before the next change and see if it unclogs things before you drop the pan. Some people swear by it, others curse it. Could be of help in your situation if you suspect oil ports and/or oil pickup are getting gunked up from the oil additives you've been using.

 

[Merc225hp]

As posted it's time to drop the oil pan and install a new HV oil pump with a new pickup tube. Stop using all that stuff in your oil, pick a good brand of oil and stick to it.

"Could be of help in your situation if you suspect oil ports and/or oil pickup are getting gunked up from the oil additives you've been using."

^^^ NYCruiser nailed it.

 

[Firefighter613]

I replaced sending unit yesterday. Light don't come on now, but oil pressure is still pretty low. Cranks at 40, but drops on down, borderline... not too sure. Is there any way around not having to drop the pan? Last thing I want to do is do all that. I'll switch to royal purple or whatever, afterwards. Its been cold lately with this winter storm so engine could t get hot like it usually does. (41 degrees) thanks guys.

 

[dodge dude94]

You might try 5W40 diesel oil. It has some extra cleaners in it as well as the higher viscosity. Increased my oil pressure as well, granted, I wasn't having an issue with pressure to begin with.

 

[Merc225hp]

I replaced sending unit yesterday. Light don't come on now, but oil pressure is still pretty low. Cranks at 40, but drops on down, borderline... not too sure. Is there any way around not having to drop the pan? Last thing I want to do is do all that. I'll switch to royal purple or whatever, afterwards. Its been cold lately with this winter storm so engine could t get hot like it usually does. (41 degrees) thanks guys.

Well if you don't do all that then you might just end up replacing the motor. I would say 2hrs work, remove neg cable from the batt, remove both motor too tranny brackets, remove starter, remove inspection cover on tranny, unbolt the oil pan, drop it down, unbolt the old pump, clean the oil pan, prime and install new pump and tube including a new gasket, tq down the new oil pump, install new oil pan gasket, install oil pan, inspection cover then the starter and both brackets, hook up neg cable. Done deal.

This is also covered in the FSM in much more detail.

 

[dodge dude94]

^Papa Merc, hashing it out once again!

 

[NYCruiser]

Or seafoam in the crankcase………………….make sure you follow the directions to a "t"……...

 

[Firefighter613]

I guess I'm bout to seafoam my crankcase, maybe it'll work in my favor. Hate it when this truck picks on me. Ima about a quart over, should I drain a little before I run seafoam through it?


Thinking about going to 20w50 racing oil.

 

[NYCruiser]

Why are you a quart over? I'm hoping its because you over added.

Don't run overfull on oil. It will cause other problems like foaming and seal failures.

Yes. Drain a quart out and get the level so its on the proper mark on your dipstick.

Then follow the instructions in the link below for "pre-service cleaner". Follow the instructions precisely. You will need 1 1/2 ounces of SeaFoam for each quart of oil in your engine. You may need to do this more than once if your engine is very dirty. If you think that is the case, get some cheap oil to refill with and reapply.

Do not do the "after-service additive" procedure. I don't recommend it. Once you put this stuff in, the oil will get dirty fast. I would just be prepared to do an oil change at the interval indicated in the pre-service instructions.

Using Sea Foam Motor Treatment in crankcase oil - Sea Foam Sales Company

How many miles are on this engine?

 

[Merc225hp]

Mr. NYCruiser why are you getting him to run more engine cleaners through it? He has been slamming it with Marvel mystery oil. If the oil pickup screen is plugged no amount of cleaners will help. These motors have one of the worst pick up tubes ever made.

Op all you are doing is covering up a easy cheap fix, racing 20-50 oil in a stock motor that takes 5-30 or 10-30............

 

[NYCruiser]

He said he wants to try and clean some of the sludge out to avoid dropping the pan if possible. Not an unreasonable attempt. He won't cause any damage if he follows those instructions carefully. It will either help, or it won't, and then he can proceed.

 

[leadrofthepak]

Its likely the additives that have gummed up his oil system to begin with. Definitely need to drain down to the correct operating level. Seafoam may help, if done properly. Heavier oil may show you higher oil pressure at the guage but if your oil pump is already struggling to pump oil due to sludge/clogs you will do more damage than good. Heavier oil will be harder for the struggling oil pump to push through the motor. Running heavier oil is typically a last ditch effort to string out an already leaky/oil burning motor. There is a reason the truck is meant to run 10w-30, that is the oil the pump is designed to pump. Hope some of this info helps.

 

[dodge dude94]

Drop the pan on that ******.

 

[Firefighter613]

I've leveled the oil out now, it fluctuates on the gauge a little still, could the port where the sending unit screws in be clogged? Reason why I'm beating around the bush is because I don't have the time nor the things to drop the oil pan, I mean you have to raise the motor, right? And 20-50 would definitely help here in the south Georgia summers, I mean 110° heat.... all this started when I ran 10-30 in it, when I bought it, it had 15-40...

Here's what I think I'm going to do. (Might regret it)

Seafoam,
20-50 oil change

Observe.

If nothing changes, drop the pan. There is a vacuum line I broke while changing the sending unit, from the dash to the TB, but surely that shouldn't be the cause... I mean who knows how long this has been going on anyway, the sending unit before was failing for the last 4 months or so...

Could it be another faulty sending unit? That crap Advance sells.... you never know.

 

[Merc225hp]

Use a mech oil psi gauge and test the oil psi see what it's at that way. No you don't have to lift the motor to remove the oil pan.

 

[NYCruiser]

There might be a reason the PO was running 15-40. I hope not.