I have a '02 f350 I purchased from my neighbor 6 months ago. It ran great 2 weeks ago. 3 weeks ago I had the CPS replaced at ford, when I picked it up it seem to idle rougher and seem to lack the power it had when I dropped it off in the morning. It had a #4, #5, #8 contribution failure codes stored, so I replaced the CPS with a "black" CPS from international. It seem to idle better but #4 still fails the contribution test and rotational velosity bounces between 0-18% so I'm thinking # 4 injector is going bad, # 5 will bounce up to 8-10% but they are next to each other in the firing order so I'm thinking its #4 affecting #5. So I got a new injector, but before i had a chance to replace it I lost oil pressure on the factory gauge, I replaced the sending unit on top of HPOP res. still no pressure. When the oil pressure gauge started acting up the trans gauge started acting weird also, when I start the truck it comes up to the bottom of the scale and withing 30 seconds it is 3/4 up the scale. I have a Genisys scanner, trans temp showed 59* at the bottom of the scale and when it went to 3/4 the fluid was only 68*. The oil level stays the same in the HPOP res. about 1/4-1/2" below the filler plug after starting and after sitting for 10 hours. I tried changing the oil, I cut the filter open and looked for any bearing material, it was clean. I changed the low pressure oil pump, it had more play in the housing then the new one, but still not enough to move the gauge, there were no marks on the timing cover, where it may have been grinding the cover and losing pressure. The guy i bought it from changed the oil every 4000 miles with rotella and a wix filter (has the recipts to prove it) ICP is 550-625 at idle and will climb to over 1500 psi just reving in neutral. I tried adding a quart of oil and jacking the rear of the truck up, no change in pressure. Also the turbo makes a "gurgling" sound when you let off the gas, almost like wastegate is no opening fast enough to vent pressure and its rattling the turbo. The turbo shaft spins free and there is no movement in the shaft. I know it need a # 4 injector based on rotational velostiy readings, but I want/need to fix the oil pressure problem first. So far I have checked/changed

CPS with international part
Oil pressure sending unit for the gauge
LP oil pump, and check cover for wear
Added a quart of oil and jacked the rear of the truck
Oil level in HPOP res. hot/cold
verified ICP pressure idling and reving

Do the clusters in these trucks go bad? Any known electrical issues with oil pressure/trans temp wiring harness? Does the wiring go directly to the cluster or does it go through a module? I have alot of automotive experiance but this is my first diesel and first Ford, so I'm going over the basics but need a little more insight from a pro, any help/ideas would be appriciated, thanks

Rob

Sorry for the long post, just tring to give you as much info as possible, thanks

 

Bump. Good information. Some of the experts will be along shortly that will help. Hang in there.

 

Did you verify the low oil pressure with a mechanical gauge?
You might be chasing your tail with an electrical gremlin.

 

That is just what I was thinking Dan.

 

If it is still running & starting normally , you still have oil pressure , Like was said I might check it with a gauge as well

 

Curious to hear out come. Bump

 

I went to check pressure last night, and I lent my pressure tester to someone else, as soon as I realize who I lent it to I will verify oil pressure..

 

That sounds just like me. Good luck.

 

Does anyone have or have a link to a wiring diagram for the oil pressure switch?

 

PM your E mail address, I will send one to you, I am not bright enough to post here, otherwise I would.

 

For some reason PM isnt working for me so its

rodneyalligator@hotmail.com

Thanks

Rob

 

Check your mail box, should be there shortly..

 

Cool, thanks Pat!!!!

 

Starting in 2002 the instrument cluster got it's data from a serial line. Some things are wired directly, but trans temp isn't one of them. Only oil pressure switch, coolant temp (diesel), and fuel sender go directly to dash gauges (other indicators are direct from their respective modules too but not important here.)

The oil pressure gauge is just an idiot light if you didn't know that. Find the oil pressure sender. It should only have one wire going to it. I'm not sure you changed the right one. Unplug the wire and ground it and the gauge should move to the normal position. If it doesn't you have a problem in the wiring or the dash.

It's rare for the HEIC (hybrid electronic instrument cluster) to have issues outside of the mileage display not working. Usually the gauges etc don't fail. Again, that said, the trans temp gauge is also an idiot gauge, so a small amount of temp change could change the gauge a lot, to get it into the normal range. Then a lot of change is necessary for it to move again to hot.

The gurguling sound is probably normal, the wastegate isn't designed to open fast to vent pressure, it is used to regulate drive pressure or exhaust back pressure. You are probably hearing some compressor surge.

Check your voltage readings, if they are off, I have seen where the internal voltage regulator in the PCM will go bad and make all sorts of things act weird. You can put the instrument cluster into self diagnostics by holding the trip reset while turning the key to the on or start position. You can then cycle through different tests and modes by pressing the trip button. A couple of imporance are the RPM, needle sweep, and voltage reading. That can help troubleshoot other issues.

That was a lot of work to change the oil pump on a whim, so lets try and diagnose this and get it figured out. I really really don't think you truly have a low pressure oil pressure problem, the truck probably wouldn't run if you did.

 

Cool thanks for the info. I know ford uses idiot gauges to keep people from coming with problems/complaints "the gauge always used to be here".. The compressor surge noise may have been there before I am just more aware of it now because of the other problems. Changing the oil pump was actually fairly easy, it only took me about 3 hours. That included the trip to retreive my balancer installer. The switch I changed was located on the HPOP res. on the passenger side, it was a 1 wire sensor. If I remember it was a white/red wire. I also noticed the brake warning light doesnt work. The diagram for the cluster shows the oil sending unit on pin 8 and brake warning light on pin 9, I'm wondering if the 2 could be connected?