CR Oiling issue

J.Keith

J.Keith

Pro Diesel Tech
Joined
Feb 14, 2007
Messages
708
I have an early 03 (250hp) cr here at the shop that pretty much has me stumped so I'd like some ideas on where to go from here.
Truck came in for a hard start cold which led to a new set of injectors as the stockers were returning TONS of fuel. No cross contamination into the oil. When I got it running in the bay to do the return flow test, the check gauges light came on and the oil pressure gauge dropped to 0. So, I threw a mechanical gauge on it at the filter head to verify and sure enough, this sucker takes a good minute to a minute and a half to build any oil pressure at all and even then it came up very very slowly. So, I stopped, called the customer and he told me it's been doing this for the better part of a year every morning. He just revs it up right after he start is so the light stays off :bang He was writing it off to a "damn computer thing"

Truck needed the gearcase resealed anyhow so I sold that job and tore it down hoping to find some damage at the oil pump. Wrong, everything looked perfect in there. Put in a new pump anyhow and closed it back up.
Fired the motor and again, took more than a minute to build pressure and threw the light on. Once it starts getting pressure it builds to about 60psi at idle (cold) and from then on acts totally normal, even when its up to temp.
Pulled out the pressure regulator and mic'd it and measured the spring and they are dead on. Primed a new filter and spun it on. Still the same damn problem. When I pulled the filter I noticed that it was about half empty even though the truck had been running just 10 mins before.

Let it set for about 4hrs and the filter was completely empty.

So I'm thinking that it's draining back/siphoning and the oil pump is losing its prime.

Fast forward to today and I have changed the filter (again. Rule out the simple), no change. Pulled the pan, pickup is clear and bolted up nice and tight. Pressure tested it and it's not cracked. Pulled the filter head/oil cooler and the gasket was fine, nothing that I can see is compromised in there. Pulled a rod and main cap and the bearings look new.....


What the hell am I missing?
Thanks in advance fellas. I feel like I've inspected the entire oiling system and cant find anything wrong.
 
Maybe an oil cooler restricted have you tapped gauge into main block oil rail and tested presure ?
 
Mine has been doing the same thing for about 8-9 months too, I just felt it was oil density related since even thought the oil is a little thicker as it gets a little older the analysis was OK, and every oil change it acts fine for about a month then starts up again. The other day is stopped doing it on it's own but that was because the oil pan was having fuel added to it thinning the mix. I just start the truck and rev it to about 1300-1400 RPM's and if you do that for about a minute all is well and the light never comes on, if you drop the RPM's too soon you loose pressure and have to start the process over again, the other thing that made me think it was oil thickness was because when it is cold out it happens more frequently then warmer weather...
 
yep mostly likely could really be any of the bearings, I've found cam bearings in the past.
 
I would go with cam bearings to be honest.

I would "hope" for something easier but I think you are going to find some actual damage in there.

I'm on my phone do I can't go back to re-read what you found with the mech gauge but if it was reading basically the same as the dash then again you have a problem in the bearing clearances somewhere in there.

I'll be watching and hoping right with you that that's not the case.



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Usually extra clearance on bearings will have good pressure when cold when the oil is thicker and will drop steadily as the oil warms up and thins out down to 0 psi at idle.

I dont have any ideas for ya at this moment though.
 
bdp said:
Usually extra clearance on bearings will have good pressure when cold when the oil is thicker and will drop steadily as the oil warms up and thins out down to 0 psi at idle.

I dont have any ideas for ya at this moment though.
Click to expand...

exactly it should get worse as it warms up
 
I saw a Cat dozer in our shop a few years back that had a similar problem. After a bout a week we discovered that some gunk had built up in the filter head, right at the pressure sensor and test port, that was blocking the flow of cold oil. As soon as the oil had warmed up enough it was able to squeeze past and push the sensor. Have you had the oil analyzed or cut the filters open?
 
Forrest Nearing said:
what brand oil filter is on it?
Click to expand...
Amsoil filter is what it came in with, swapped it to a AC Delco for testing.

I think I've fixed it guys. The filter housing had a very small amount of buildup around the outside of it near the top. I'd written it off at first as residual from a leaky valve cover gasket. However once I'd been into the rest of the system I put this back on the table and looked into it from every angle. What I think was happening was the outer edge of the filter housing wasn't sealed all the way anymore and it was causing not only an entry place for air to allow drainback, but it would have created a vacuum leak when the pump was trying to prime, thus causing this problem.

I flat sanded the filter housing, both sides of the cooler plate and the block. Put in new Cummins gaskets (thanks Jeff!) and so far, it's fixed. Only taking around 4-6 seconds to build pressure. It's sitting overnight and I'll know for sure in the morning.

Its sure kicked my ass. Got my fingers crossed!
 
Warpig said:
I have always used Fleetguard, recently I heard a rumor that they are now being made in China.....wtf?
Click to expand...

The last shipment that I received were made in Mexico, the paint sucked azz! I just hope that the filter is as good as the US made product.
 
OK, so since mine is the Amsoil filter on the amsoil filter base since it's relocated for the bypass should I look into new filters and cleaning up the mounting surface? It makes sence that it seems find for a little while after I do an oil change if it is just something up with the filter mount, I will look into that on mine...
 
Had a 6.7 do the same thing and ended up being pick-up tube/gasket issues.
 
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