And the Saga Continues - Need More Help

[apextrans]

Back again The latest development in the story is as follows:

Engine has oil mixed with 2 gallons of Lucas & some Trucker's Lube (Restore for trucks). It doesn't seem to be smoking as much while running. The damn check engine & engine protection light continue to light up after the motor reaches operating temp (180*) only when driving. At idle the light are out. Put it back in the same shop that did most of the work, thinking it might be something they missed & I already paid for scan time, so.... They scanned it again & are telling me "the motor is just worn & won't build enough oil pressure to keep from throwing a code to the ECM. Needs an inframe & there's no other fix" They told me a C-12 needs to see a minimum of 30psi to not throw the code. Anyone know if thats true?

I just listed this shitwagon on the internet to get rid of it, thinking my problem was just a sensor or something. Now I don't know what to do to get the lights off so I can get rid of it.

Is there any way to boost oil pressure without an inframe? More Lucas? 100% Lucas? Anyone pipe in. I need to get rid of this thing. I've got a used 05 Peterbilt 379 waiting for me for no money down!!!

 

[Jarlaxle]

Uhh...maybe there's another sender that will read higher?

Or the ECM can be reprogrammed?

(Or maybe it will run another 250K like this?)

 

[EMD Diesel Power]

Put the thickest oil in there that the engine will stand..... I still stand by my straight 50 wieght oil suggestion. Same weight used in most locomotives.

The present oil in the truck is getting thin when it gets hot at normal temps (normal for the oil) but with the terrible engine wear it will drop the pressure and irritate the ECU. 30 PSI sounds about right for the low end sensor value... not much ya can do on that.

If I had the computer I can change some settings for you and make the problem disappear. :Sly I know the forced shutdown and forced limp-home modes can be turned off or delayed greatly on a low-oil pressure value (as well as others). But good luck finding a dealer that will go to that extreme setting for you.

There is always the electrical tape route... or the bad bulb in the appropriate light route too.... but if the truck derates... whats the point? Im not sure what your rig is set to do..... so just guessing. BTW, how many miles are on this thing? Seems to me that its a younger rig and having an inframe now isnt quite right.

There is always the blow it up under a hard pull method too... but I understand you want to get money back... soooo I do hope you break even on it... or even better yet, do some profit.

 

[maniac]

I would think that at idle the light would LIGHT, thats when the oil pressure is the lowest ( and so is the RPM)

I would say heavier oil too, don't know about all Lucas though, maybe 1/2 50 weight and half 15X40 and 2 Lucas.

Did you ask then about just doing the bottom end? seems to me oil pressure is bearing related, I know you don't want to throw any more money at this, but maybe a bearing roll will up the oil pressure enough to trade it away.

 

[scrappy]

I would think that at idle the light would LIGHT, thats when the oil pressure is the lowest ( and so is the RPM)

I would say heavier oil too, don't know about all Lucas though, maybe 1/2 50 weight and half 15X40 and 2 Lucas.

Did you ask then about just doing the bottom end? seems to me oil pressure is bearing related, I know you don't want to throw any more money at this, but maybe a bearing roll will up the oil pressure enough to trade it away.

I found this thread tonight so I am not fully in the loop but Oil pressure is at its lowest point @ idle, if the light is on above idle and not @ idle it could be a bad sensor. or there is something else entirely wrong that the dealer can't or won't find to fix this.

 

[EMD Diesel Power]

Gee did I miss the light out at idle thing.

Does the lights stay on at idle AFTER they have been tripped at highway driving speeds? An on- off- on.... type of scenario? I know the check engine will stay on usually.... however the engine protect should be *as it happens*.

Bearings are usually at the bottom of my checklist on low oil pressures. If bearings ARE suspect in this case, it would be the mains. However if the shop says you need an inframe... the mains are most likely worn or shot, along with rings and everything else from past posts by Apex regarding how the truck ran.

Apex has said that the truck smoked pretty good under load and stuff.... so that tells me the rings are gone. And if the rings are gone, fuel dilution is a real possibilty and that would really thin out the oil, especially when hot. Fuel dilution will also wipe out the mains over time too... although not as fast as a coolant leak into oil would.

Either way its time to get rid of the moneypit and get that Pete. Any possibility you could trade it on the Pete or would you lose your butt on it?

 

[apextrans]

How do you do multiple quotes in one reply?

I called the CAT facility in North Carolina that has worked on my Pete a few times, about this. They are top notch & I trust them a great deal. They have found two problems on the Pete no one else came close to finding. He said that 25-30psi is PLENTY to keep a C-12 happy. They don't kick into protection mode until 8psi of oil pressure!! He suggested if I get the truck to him he could reprogram the ECM to be happy with 25psi. He told me to get it the hell out of wherever it is & take it to CAT locally.

I discussed with the shop it's in, the fact that the lights come on under load when the oil pressure is highest & off @ idle when lowest. "Thats just the way it is when the engine is worn" Things went downhill between me & the service write after that. The truck is coming out of that place tommorrow & going to CAT.

EMD, I'm going to 50wt ASAP (maybe tommorrow) & have thought about pulling some bulbs :Sly because I got a guy who wants to look at it Friday. Unless CAT can slide me in quick & get it straight. I don't want to be dis-honest about the deal so if I pull 'em, I'll still try to get it staightened out & put them back in. I don't want to screw someone like that.

Maniac, any idea what it costs to do the bottom end only?

Scrappy, I suggested a bad sensor & the shop said they "hooked in bypassing the electronics to see if the laptop (engine) told them the same thing the gauges did staight from the motor. ***!! Is that even possible. They're saying there no bad sensor because the laptop read the same as the gauges. I think you hit the nail on the head with your last statement. This place doesn't seem to know what there doing or don't want to see the truck anymore.

I listed this thing for about $5000 more than I got in it & got a hit the first day on the web. I've got some wiggle room so worst case I'll break even......if I can get the lights out honestly.

 

[apextrans]

Gee did I miss the light out at idle thing.

Does the lights stay on at idle AFTER they have been tripped at highway driving speeds? An on- off- on.... type of scenario? I know the check engine will stay on usually.... however the engine protect should be *as it happens*.

Either way its time to get rid of the moneypit and get that Pete. Any possibility you could trade it on the Pete or would you lose your butt on it?

Once the motor is up to temp the lights (both) will light up under acceleration. If I let off the throttle and coast the truck, the lights (both) will go out @ about 1100 on the tach. Get back on the loud pedal & same thing happens. Repeat above. Now, at idle I have no lights at all. Looks fine until you get moving again. The lights are lighting when you would think the oil pressure is the highest.

The Pete is an '05 but isn't for sale by a dealer so no trade in possibilities there. Plus, I would get screwed BIG TIME.

How do you tell if there's fuel dilution? Oil looks like oil on the stick. No bubbles other than normal.

 

[EMD Diesel Power]

Once the motor is up to temp the lights (both) will light up under acceleration. If I let off the throttle and coast the truck, the lights (both) will go out @ about 1100 on the tach. Get back on the loud pedal & same thing happens. Repeat above. Now, at idle I have no lights at all. Looks fine until you get moving again. The lights are lighting when you would think the oil pressure is the highest.

The Pete is an '05 but isn't for sale by a dealer so no trade in possibilities there. Plus, I would get screwed BIG TIME.

How do you tell if there's fuel dilution? Oil looks like oil on the stick. No bubbles other than normal.

Fuel dilution is usually found through smell..... if its a major leak, it will be obvious right on the stick..... The oil will also appear to be thinner and more *watery* compared to the usual where it stays on the stick.

I have had instances where I did not smell it right off hand, but ran it between the fingers and then could smell it. It will jump out at ya.

Oil analysis testing will also find it. Basically its a flashpoint test.

I have a way of doing it myself, basically involves a hot plate, heavy-*** steel cup (like the kind for melting bullet lead in) and a thermometer. Add a real small flame just over the top and heat oil sample until it starts to flash over (will do so with a distinct pop). Take temperature and deduce the info. I've had some locomotive oil samples that all but blew up on me at less than 290 degrees.... not good. A good sample is usually around or over 410 degrees. I can also test for water too by watching it boil out at around 220-230 degrees....

Now as for your truck.... Oil pump being a culprit is now a possibility... low speed low pressure... high speed.... pump cant keep the pressure up due to leakage and its tripping the alarms (ECM will also correlate with engine RPMs as well). This might explain all the cylinder wear too..... if the pump wasnt putting out the pressure... the cylinder ***-pipes and the walls may not have been getting enough lube for full protection.

Heck... it could be a pressure regulator valve too..... Dont think it would be a filter bypass.... you have too good of a PM program for that.

 

[towcat]

scotty-
here's a suggestion again. go find yourself a rollover with a good motor. I am sure they can be found out there alot easier than in Ca. I tend to do better with the big rig wrecks in Or or Wa. It helps I have a friend with a lowboy to pick up the carcassas and room to pick one clean. With three guys going into a wreck, there isn't much left when we get through with it.

 

[maniac]

Cat here advertises the lower end @ $1300.00

Oil pump DOES sound like it can't keep up like EMD said.

Fuel dillution WILL take about 20 pounds of oil pressure out of it also, it will be over the full mark and you should be able to smell it, not usually bubbly though.

 

[apextrans]

I'm leaving now to get it out of the shop & take it to CAT. At this point, I just want the lights off (without pulling the bulbs). Not interested in fixing anything else. I've got a full load sitting on the truck right now that needs to be off-loaded or delivered, then I think it will come off the road (not that it ever really got on the road).

I appreciate all the input. This has been a hard lesson learned. I'll let ya'll know what CAT finds though.

 

[apextrans]

Just got back from dropping the **** @ CAT. I did notice something else this morning though. When I started the truck to leave, oil pressure was about 50-55psi. As I drove & the motor came up to temp, the oil pressure fell off to 25-30psi. The drop in pressure was sorta equal to the rise in temp. What does that mean...if anything?

 

[towcat]

Just got back from dropping the **** @ CAT. I did notice something else this morning though. When I started the truck to leave, oil pressure was about 50-55psi. As I drove & the motor came up to temp, the oil pressure fell off to 25-30psi. The drop in pressure was sorta equal to the rise in temp. What does that mean...if anything?

you have a problem with keeping up oil pressure when its warmed up. I am thinking loose bearing clearences

 

[chris88]

Every engine I have ever seen has higher oil pressure cold than it does hot. I would take it to a good shop that you trust and see what they have to say. If you can break even selling it as is I would do that before dumping any more money into an in frame or any other work. What ever way you chose, good luck.

Chris