Well, my truck is broke again... just got home from a trip to moorehead,nc. pulling a 31 ft fifth wheel and just about an hour away from drop off, I pulled up to a stop light and my oil presure gauge went to zero??? I put my foot on the gas pedal and raised the rpm's to 1000 and the gauge came back up, but when I tried to get going the truck had no power, at least very little. so I stopped to check the oil level and it was down only a quart so I topped it off.. then tried to start it and it cranked and cranked and cranked the finely it started. still acted the same.. so I nursed to drop off the trailer. luckely, I have installed a high idle switch so when I stop i can give it high idle so it will stay running. stopped into a ford dealership and they told me that the engine had to come out to repair...you guessed it, down the road I went. it's alot better without the trailer but it's still not good. I pluged in my scanner and found out that my ICP is low. will not exceed 1400 psi even when it call's for more. if i gently press the throttle it's fine up till say 1400 then fall's off fast to 600 psi. This is getting hard to control because I know that I have the mountians coming up. anyways, I make it back home last night and shut off the truck, now I have to get it to the pole barn and have not tried to start it yet. my problem is, I don't know if it's a problem with the low pressure oil side or it's the high side. If there is a problem with the ICP will it cause the low pressure oil problem that I'm haveing or not?? Thanks for any help you can help with..Dan

 

Your oil pressure gauge is getting its reading off of the the low side. Post oil cooler / oil filter (where gauge pressure is read) is where oil is then fed to the high pressure pump. I'd suspect you have a problem on the low side. The low pressure side is also the source of your other engine lubrication (turbo, valve train, etc...) so be careful driving it like that.

Mark

 

ok, lets get some info. do you have a early or late build 04? (look for an icp sensor on the right valve cover) what kind of weight oil are you using and when was last service interval.

 

sorry about that... It's an 04 build date 10/03 sensor on right valve cover. rotella 15w40 and about 6000 on oil change( I know, Iknow I will do this first thing this am.)

 

if it is the fitting on the back of the pump, and it is bad enough, it will be a lose of base pressure. also are you running low quality oil filters? there was an issue about some filters causing a no oil flow in the filter housing. have you had any injector failures? there have been some issues with the base oil pump getting damaged from snap ring pieces.

 

fitting on the back of the pump? not sure about this...I do have a random injector misfire.number 6 does not like the cold weather and trips the dtc but clears up after a couple of min's of running...if it was snap ring pieces in the base pump, you sure wouldn't think that I wouldn't have made it 1000 miles back home.I've been getting my oil changes done at my local oil change place and not sure on the brand of filter's used but I will change it myself with a better brand.. just to start.

 

i was giving you possiblities. i cant diagnose your truck online. you asked for help and i tried.

 

If they were using one of those "too short "filters, it would be losing pressure due to drain back into the pan. Try putting in an oem filter.

 

BowTieHatr please don't get upset with me. I don't want to come off sounding cocky, my typing skills might do that, but I assure you that that is not my intention. And yes I did ask for some help, and need some help, and I thank you for any help you or others may be able to give... anyways..... I just changed the oil with 15w40 rotella and installed a motorcraft filter. need to hookup my laptop and test ride. should know soon...

 

Still not right. at idle, oil pressure gage goes to zero, just off idle jumps up to normal. ICP does fine up till around 2100 then starts to fall off rapidly. at idle ICP is at 580....starts hard after it sits for awhile and sometimes gets a code for low oil pressure while cranking. if its started soon after its warm it starts fine.

 

no offense taken. it is either a base pump or hpop, or a very bad leak.

 

I agree with you... I'm just having a hard time understanding why two problem's starting at the very same time that are somewhat indipendant of each other. I mean, lets say base pump is the problem...why the problem with HPOP over 2000 psi? or Hpop is the problem, why base oil pressure having problems at idle??? major oil leak? yup, makes sense for the HPOP but how would this make the base pump low at idle? Do you see how I cannot connect the two of these together?

 

the base pump feeds the hpop, and if there is a leak bad enough in the hp system, then you will have flow in the base system, but no pressure. and the flucuations could be signs of a leak.

 

It sounds like a low pressure oil problem to me. The high pressure oil system relies on the low pressure oil system, so a loss in low pressure oil will starve the high pressure oil system.

I would first check the oil pressure relief valve (I can't remember for sure what it is called). It is in the bottom of the front cover on the passenger side just behind the crankshaft damper. It is a large (10mm?) allen plug, spring and valve. Remove the plug and spring and see if the valve slides easily in the bore. Also check the valve and bore for scoring.

BTW, I don't recommend going over 5k miles between oil changes.

 

now that makes sense!! any idea on where to start looking for a leak on the hpop side??