Oil Pressure

[DogramTD]

I just moved to Cheyenne recently and spoke to the dealer about it; I mentioned this being under warranty previously and not getting repaired... I could tell it wasnt goning to go over well.

 

[BIGNASTY]

On start-up, the oil pressure will drop to zero after about 5 seconds. I cannot find any pattern to this except for that it usually happens (randomly)in the mornings. It will drop to zero and the check guages light will come on. If I immediately shut it down and restart it, it is fine. Unfortunately, there are times where I will just reachover to start the truck and walk away while it warms up. If the pressure drops off I can tell because it will sound a bit more chattery than usual, at that point i'll walk back to the truck and sure enogh, it has dropped to zero.



I have brought the truck in to the dealership 3 times for this (under warranty), one of the times they kept it for a week. They have replaced the oil cooler (thinking it was a stuck check valve) and they have replaced the sending unit 2 times. Nothing has fixed it and now they wont touch it unless I pay because the warranty has expired.



Has anyone experienced this and can tell me what is going on? I would think its just an electronic issue but I can hear the lack of oil pressure in the motor when it happens. HELP!#@$%!

you say that you can hear the lack of oil pressure when it happens. Have you ever taken off the rocker cover or maybe pulled the plug on the top of the OEM oil filter housing to see if indeed you have no oil press. Could even put a gauge on the filter housing to see if pressure is present. JAT im not a mech with these NEW FANGLED trucks When new I installed the Pre Luber no question as to oil pressure I kind of like that it shows up on my gauge before I even start the motor. The gauge is a manual aux gauge not the one in the dash

 

[DogramTD]

I just ordered a manual gauge to install in the cab; it does read from the filter housing. When it happens, I dont take any chances and shut it down instantly. If by chance i start it and walk away for a minute and it happens, there is an audible difference in sound. I'm quite positive that it is a mechanical issue and not electrical. I have pulled the cover many of times but not while it was running to inspect for OP.

 

[Bill Weber]

When you install your mechanical gauge you will know for sure if the press is really dropping. If the press really goes to zero I would have it towed to Dodge and make them fix it.

 

[hcole]

Maybe I'm missing something but if I'm diagnosing this right I would say that the oil pressure relief valve built into the oil pump is sticking open and repeated starts and stops is breaking it loose only to stick again later. I've had this happen once in an old chevy 427 that I had rebuilt and wanted more oil pressure so I decided to stretch the spring. Bad idea. It kept sticking occasionally and i finally had to replace the pump.

 

[rbattelle]

DogramTD, what brand oil filters are you using? I'm wondering if the bypass in the filter could be screwing you up somehow.

Maybe I'm missing something but if I'm diagnosing this right I would say that the oil pressure relief valve built into the oil pump is sticking open

That's also a possibility, except the relief valve isn't in the oil pump, it's in the main oil rifle adjacent to the filter housing. If you're looking at the filter, there should be a hex-head plug just to the right.



Remove that hex head plug. Inside the bore is a spring and a plunger which can be removed with a small finger or a pick. Inspect the spring and the plunger, paying particular attention to anything that might cause the plunger to stick. Clean with a suitable solvent and reinstall.



That's the first place I'd look.



-Ryan

 

[mwilson]

Ryan makes a great suggestion, I would go one step further.



Look the plunger over for shiny spots and/or drag marks, swear at at and throw it in the trash, then replace with new if not too expensive.

Where the issue seems to be getting worse I would not trust the spring either.

You may also find that the spring has a broken coil when you get it out.



As far as the oil pump goes, as said above they either pump or they don't.



Provide your Engine Serial Number and I will look the spring and plunger for you, also check pricing to see if it is within reason.



Price might not be bad, I don't mind checking for you.



I am working here until 3. 00pm so if you respond by then I can give you a fast answer.



Mike.

 

[DogramTD]

Maybe I'm missing something but if I'm diagnosing this right I would say that the oil pressure relief valve built into the oil pump is sticking open and repeated starts and stops is breaking it loose only to stick again later. I've had this happen once in an old chevy 427 that I had rebuilt and wanted more oil pressure so I decided to stretch the spring. Bad idea. It kept sticking occasionally and i finally had to replace the pump.

Thats what I was saying, that prv is in the oil cooler; mechanically, its the only thing I can see going wrong. The dealer did say that they did something with it although its been a few years and I dont recall what it was; I was deployed and my wife is the one who took it in.

 

[DogramTD]

DogramTD, what brand oil filters are you using? I'm wondering if the bypass in the filter could be screwing you up somehow.



I use FG filters.

Ryan makes a great suggestion, I would go one step further.



Look the plunger over for shiny spots and/or drag marks, swear at at and throw it in the trash, then replace with new if not too expensive.

Where the issue seems to be getting worse I would not trust the spring either.

You may also find that the spring has a broken coil when you get it out.



As far as the oil pump goes, as said above they either pump or they don't.



Provide your Engine Serial Number and I will look the spring and plunger for you, also check pricing to see if it is within reason.



Price might not be bad, I don't mind checking for you.



I am working here until 3. 00pm so if you respond by then I can give you a fast answer.



Mike.

Thanks Mike, I away from home right now until next weekend but I will get it to you then. I have been looking around as I have been suspecting the PRV as well; at the price of $80, I would just replace the entire cooler rather than just the plunger and spring. This way they are born together and mate together.



Of course all this is subject to the results of my test after installing my manual gauge. I am almost certain that the pressure is in fact dropping off and its not just an electrical issue. I think this because of my keen ear to mechanical sounds and the fact that a few others are having the same issues and symptoms I am.

 

[mwilson]

Just used the ESN from my '06 for a quick reference. .



Item #4 is called a pressure regulator valve which is what I was thinking of that used a spring.



Notice that #9, that is called a pressure relief valve. That could also cause trouble.



The way this looks up for my truck is with all separate parts, but you would be in that $80. 00 to $90. 00 range from what I see.



Mike.

 

[DogramTD]

Just installed the gauge and verified that in fact there is no pressure at start up for close to 30 seconds. I will time it tomorrow to see how long it takes to build. When it did finally build it shot up to 85 PSI. Now I need to research the acceptable pressure build time to see if possibly the ECM is too quick on the draw to warn on the lack of pressure, or there is an actual oil pressure problem here; I am thinking the latter of the two. Since the Oil Cooler and PRV is my first suspect, at only $80, I will change it first. Gonna do a bit more research first.

 

[Mhannink]

85psi seems high for idle. i think it should be in the 20psi range. i too am thinking that its the pressure relief valve. this is more to mike, but working professionally i have ordered parts where you have to take old parts and install them in the new one. i dont know if this is a similar situation however if they changed the oil cooler maybe they didnt change the prv. even at 80 bucks i would pull it out and inspect it before replacing it. im probably preaching to the choir, but look for shiny areas that indicate wear, broken or weak spring, propper seating, etc. if nothing is found, i would replace those parts and see if it changes.

 

[brods]

I was playing around with a poor mans preluber (ie cranking the engine without starting it to get oil pressure, as is recommended for ISB engines in welders, marine use etc) and found a few surprising things that may help you. It took 31 continuous seconds of no oil pressure for the ECM to sound the alarm. Iirc that delay might depend on what software is in the truck. Supposedly the truck had the latest Chrysler flashes at the time of the tests because of using the latest Smarty tuner software.



There is some drain back and the longer the truck sat the longer it took to get oil pressure at startup. After the truck sat a few days it did take as long as 30 seconds of cranking to begin to see any pressure (1 psi). Unfortunately my notes do not show the time for oil pressure rise when starting the truck normally. After cranking for 24 seconds (no oil pressure) and then starting the truck it still took about 8 seconds of running to get up to full pressure.



Oil pressure at startup, at 61 degrees ambient temp the pressure at idle was 68 psi. The pressure was measured at the filter head with an Effector PNI024 digital sensor. Totally stock lube system with a stratapore filter. Once up to normal operating temp the pressure at idle was 23 psi.



Maybe AH64ID can post pressure rise times using his mechanical gauge.

 

[steved]

I have a mechanical gauge on the hose between the filter head and my bypass... it takes less than 15 seconds to prime even on the coldest morning. 85psi cold is about right... it should settle down to around 25psi hot idle and 60psi hot cruise.



Unless its a multifit application, our filters don't have bypass valves built into them like other applications since that feature is built into the filter boss. At the moment I also want to remeber they don't have anti-drainback valves either.



Here is my thoughts... you have an air leak or something in the system that is allowing the engine to completely lose prime, and the oil pump is needing all that time to reprime. That's the reason it takes so long to get oil pressure in the AM, and also the reason it comes on so quick upon restart... and the reason it doesn't happen driving down the road.

 

[DogramTD]

Just went out to time the OP build, of course it didnt do it this time; full pressure within 8 secs. This has always been intermittent but lately is becoming more frequent.



Steved, I can agree with you that in one way or another the oil is draining back. I've read in another post where someone had an inner gasket issue on their oil cooler, once replaced, it fixed the problem for him; someone else tried the same thing with no luck.

 

[steved]

If it were my truck, I would NOT be taking it to a Dodge dealer as most of them don't have the skill/experience to diagnose a shoebox, plus you are beyond warranty and don't need to take it there for repair. I would be finding a local Cummins dealer and explaining the problem to them, and let them fix it... likely they will be able to pinpoint the cause or will at least know where to start. I would be prepared to show them what work has been done to date, to help narrow down the possibilities.



At this point, I think you have enough data to provide to the mechanic for them to start pulling it down and look for the underlying cause. Again, if it were me, I would be looking to inspect every seal, gasket, and mating surface in the oil lube system between the pan and the filter.

 

[Mhannink]

cracked pickup tube? what are the chances the pump as a crack in it somewhere that allows air in and it drains back? maybe a poor seal on the filter when it sits? i know you said your running good oil, but could the pump housing be damaged and its not sealed as well as it needs to be. just more thoughts on what could do it.

 

[DogramTD]

Agreed, just want to start with the easy accessible item first before I dig into the front of the motor to get to the Oil Pump.



I have NO intention on taking it in to the dealership, i did the first time because I was on a 1 year deployment and I wasnt around to do anything with it; my wife took it in for me. There is a cummins repair facility near me that I plan on going to visit here shortly.



Thanks all for the inputs, if you have anything else, please keep em coming! And BTW, for those of you who run the Smarty tuner, MADS has just updated both the revo and TNT programs adding an additional 30-35 HP to the SW9 tune. I saw it when I was updating the box as i am going back to stock for the winter... Cheyenne winters can be brutal!

 

[rscurtis]

I would also vote for a problem on the suction side. Years ago, I had a '74 International PU with the 345 engine. This was the first year (of only two years) of this design, they moved the engine down and back in the chassis, necessitating a rear-sump pan. After I had the truck several years, I would get a collapsed valve lifter at almost the same spot in my daily commute to work. I borrowed the tool from the dealer and replaced the offending lifter. It happened several more times, so I bought the tool and a new set of lifters. One morning as the weather got cold, the truck was warming up, but the engine had a strange vibration and a little noise from one bearing. I shut if off and used my car. Later in the day, it was fine. I pulled the oil pan to check the rod bearings, and they all looked OK. Then, before I installed the oil pump and pickup, I set it in a pan and ran it with a drill. Sure enough, it wouldn't pick up oil at low speed- the pickup leaked air at the pump. I repaired that with the addition of a second "O" ring and put it back together. It now had oil pressure I had never seen before, even when it was new. I think it's safe to say that was the problem with the lifters- they were getting air bound. After 1975, IH was out of the pickup business, which was no great loss at that time as it drank gas like it was free and could hardly go up a hill. It also rusted faster than the Chevy/GMC products of that era.

 

[mwilson]

85psi seems high for idle. i think it should be in the 20psi range. i too am thinking that its the pressure relief valve. this is more to mike, but working professionally i have ordered parts where you have to take old parts and install them in the new one. i dont know if this is a similar situation however if they changed the oil cooler maybe they didnt change the prv. even at 80 bucks i would pull it out and inspect it before replacing it. im probably preaching to the choir, but look for shiny areas that indicate wear, broken or weak spring, propper seating, etc. if nothing is found, i would replace those parts and see if it changes.

To add to the above quote.....



Where it looks up piece by piece, (the cooler cover assembly only consists of the cover and threaded filter insert according to the parts breakdown) they may indeed have used the rest of it over.



Parts man ordered it for your warranty repair, not realizing that it was not a complete unit. Parts come in, truck gets in shop, they tear into it and then discover the replacement part is only the cover, look it over and then transfer all the small parts into the new cover rather than put it back together and have to bring it back into the shop again.



I can see it happening quite easily.



I would begin there for two reasons,

(1) Easy to get to.

(2) It has been torn into once already in the past.





Mike.