New Engine Losing Oil Pressure

[mwilson]

BTW, Two of the failures I mentioned above were due to powerline pole digger trucks operating at an extreme angle (beyond the operating angle that the engine pan and sump were designed for in this case) which made the sumps go dry while the engine was running.

Most people don't realize the multitude of configurations available and things that need to be considered depending on the application of an engine.

My point is that usually the lubrication system is pretty robust on a "B" series.

 

[Lance Butler]

Thanks for the input folks. I am now convinced that the pressure regulator plunger got stuck, I lost pressure under load and blew up the motor. I am also convinced that the engine builder then gave me back my new motor with the same problem still there.

I called the local Cummins shop. Parts will be here tomorrow. I decided to replace everything as it is cheap compared to the motor. $167 including overnight shipping for the filter plate, all the moving parts, and the gaskets. Below is my little table for the parts.

I ended up with an Autometer gauge. I spent the money for the cab mounted one that runs a wire rather than a tube of hot, pressurized oil into the cab.
It worked out kind of nice as my truck had a 2 gauge add on over the steering column when I got it. It had EGT (which I use) and transmission temp (which is redundant since I put in a Smarty Touch to watch OBDII gauges). I was not impressed with the clamp on the outside of the transmission lines sender so I was going to remove it. The engine oil pressure gauge mounted nicely there so now I have a permanent, decent oil pressure gauge.

Along the way I bought some 1/8" NPT plumbing, a 1/4" NPT valve from the air compressor section of Lowes, some clear hose and a weed sprayer bottle. This worked up pretty nicely into an oil primer that I can leave hooked up along with the new gauge. Once I get all the new parts on I can prime the system, close the valve, and crank the engine. Once I am satisfied that my oil pressure problems are behind me, I can then remove all the plumbing and leave just the gauge, mounted on a 2" nipple to get it high enough to clear the water line that runs over the filter head.

By the way, before I decided to use the weed sprayer bottle I used a gallon jug of oil based on some post I saw somewhere else. Their burst pressure is about 20 psi. Don't ask how I know, but if you want to save $13 on the weed sprayer bottle plan on spending $15 on shop towels.

It absolutely boggles my mind that this shop would not check the pressure regulator or relief valve. If I had delivered the motor to them without the filter head then it might make sense. But it was mounted on the motor when they got it and torqued back with new gaskets when it came home to me. I sure hope they make this right on their warranty plan. Note that I have avoided their name in this post as I want to give them the chance to make it right.

Description PN Price
pressure relief valve 3936365 $13.34
pressure regulator plunger 3947287 $13.13
pressure regulator spring 3925009 $7.47
filter head adapter 3909355 $22.65 (not included in total as this is included in the filter head)
gasket 3974127 $10.37
gasket cooler 2830559 $12.76
filter head 5289557 $68.3
sub-total $125.37
overnight shipping $30
Total $155.37
With Tax $167.61

 

[KParsons]

i would think that this unit would be replaced, in full rebuild? just wondering.your first engine failure is very suspect.

 

[jghflys]

i would think that this unit would be replaced, in full rebuild? just wondering.your first engine failure is very suspect.

My engine re-builder replaced the assembly with a new one.

 

[Lance Butler]

My luck continues. I got the new filter head from Cummins. It has an extra oil outlet port and no plug. I thought it was just 1/4" NPT so no big deal. Upon further inspection it is not. I think it is metric and wants a flared tube, like a brake line. Napa parts guy spent half an hour messing around and searching on the web but could not find a plug. Cummins parts lady spent half an hour. Verified that her system says this filter head is for my truck. I figure it is universal, to cover many years and many applications like industrial and military. I can't check for oil pressure until I can plug this other hole. Anyone know where I might find the plug?

This new plate is also a little different on top. Instead of two 1/8" NPT openings, it only has one and I think it is 1/4". Anyone else been down this road?

The extra port is about halfway down the plate, facing the rear of the truck. It is a bit different than the oil supply line for the turbo which is mounted in the same spot as on my old plate.

In other news, I got the old plate off. The pressure regulator piston is indeed stuck hard. I am hoping that this truly is the issue, but frankly, I am not feeling very confident as I am not lucky lately. I think I will hold off buying any lottery tickets.

Just to keep me happy, I found a couple of big pieces of garbage in the oil cooler. Not metal, but looked more like bits of old sealant that feel in the cooling system at the shop. Lovely.

I'll try the hose supply place here in town tomorrow on recommendation of both Napa and a tech at Cummins. If they can't help me then its back to Cummins. They swear the plate they gave me is what the computer says my engine number calls for, but maybe we can sort out how to order the right plate. Now that I have the old plate off at least we can read the casting number.

 

[mwilson]

Seriously, get me your engine serial number so I can attempt to help you. PM it if you prefer. There is probably a bulletin regarding the change in part numbers and I may be able to figure out the thread size....but it's all driven by the ESN.....

 

[JR]

Probably a STORM block if they didn't change anything from the gen 2 engines.

 

[Lance Butler]

57420360

 

[mwilson]

On it....

 

[mwilson]

I think I found it, does M14 thread sound reasonable??

I will phone a friend to see if I can have him get the engineering print....

 

[mwilson]

He is reaching out to his contacts at Cummins, he agrees with what I found but we want to know 100% before we give you the spec and part number...

 

[mwilson]

By the way, that oil cooler / oil filter mount housing is unique to the BEX (Ram engine)....not used on any other applications...

 

[Lance Butler]

Thanks Wilson. I found a plug at the hose shop. it is a JIC 14mmX1.5. Got it plugged, installed everything back and voila! I have pressure.

Onto my next challenge. I let it run for a while with the Autometer gauge showing 75 psi at the filter head. Revved it just a little off idle to verify boost and everything sounds great. After about a minute the check gauges light came on and the stock oil pressure gauge said zero while the real gauge showed a steady 75.

I think less than 10% chance that I somehow am losing pressure between when the oil leaves the filter and when it gets to the stock pressure switch. The only way I could see that happening if some galley plug is missing. Even then it is unlikley in my opinion.

I think it is 90% likely that there is an electrical problem with the stock sending unit. This yahoo engine builder painted the block with sensors on it so I had to scrape paint off some pins. I thought I got them all, but maybe missed this one. Probably more likely is that, like they did with the filter head, they left the sensors on the block when they threw it in the tank. I could see that making a pressure switch unreliable. So I am thinking just replace the sending unit and inspect the wires while I am there. I went through the whole harness while the engine was out, checked and fixed any wire or pin issues and cleaned up all 14 grounds.

For posterity, remember that you probably hooked you aftermarket oil pressure gauge to the ACC voltage on the key. This means it is off when you crank the motor without letting it start in order to build pressure. You need to look for pressure right after you stop cranking while the key is on. Turns out I had pressure way sooner than I thought.

Thoughts?

 

[mwilson]

My contact worked with his contact all day in between other things and we still don't have a print. But if your 14 mm plug works then I did indeed find the correct part.
I'll list it here in case anyone needs the part number in the future...

So if you change the oil cooler / filter housing on a Ram and the old part number is either 3957149 or 3965152 the new part number will be 5289557.
You will need a 3678921 plug / o-ring assembly OR an equivalent from a hydraulic supplier to close that extra hole off. Thread is M14 X 1.5 X 16.

 

[cerberusiam]

Move your gauge to the oil pressure sending unit location to validate they did not miss a gallery plug somewhere.

 

[Lance Butler]

Replaced the factory sending unit and fixed the problem. I think they left the switch on the block when it went in the tank. I had to buy the special socket for this unit as it is difficult to get to with the engine in.

Everything appears to be working well. Thanks for your help.I have about 100 miles of in town driving on it now. Oil pressure sits at 75 when on the throttle and never goes below 25 at idle hot.

There is sometimes a slightly rough idle when stopped at a light. I think that is usually an injector issue. Need to do some reading on that, but my current theory is that the builder torqued the injectors as well as they did anything else. I could see them just bolting it all down without doing the multi-step process of going back and forth between injector body bolts and transfer tube. I will probably end up re torquing them, but I want to do some reading before I go through that again as it is a bit of a project and #6 is kind of difficult to get to with the engine in. I may get my oil analyzed today just to check for any fuel in it.

 

[GCroyle]

And next on the task list is an engine oil analysis and cross fingers or go see "engine re-builder? and have a nice man to man.