Surging under load and at 70-80mph cruise

deezul · May 20, 2014

I have been working on this 2004 F350 intermittently for close to a year now. It mostly sits and the customer lives in one province but works in another, the truck doesn't see much action. The truck has been suffering from a surging issue that has been thought to be remedied but it seems to return sporadically, it now surges all the time.

The truck originally came to us as a no start - fellow tech put an IPR valve in it as the valve had the screen punched out of it (bad sign already). When he took it for a road test after the repair it was surging terribly after the IPR replacement - he then handed it over to me. When under WOT the FICM MPWR would drop right off - put a half shell in it and the surging and low voltage was fixed.

The truck came back to us this spring - surging again but not to the same extreme as it was with the faulty FICM. Fellow tech rebuilt the turbo, he felt it was turbo surge (po299 present, failed vvt test and turbo boost test). I agreed with him, the turbo needed to come off, unison ring was so badly seized on center hub that it cracked upon removal. Anyways, turbo rebuilt - surge still present.

I took this truck for a road test and captured selected pid data when the surge would occur. Heavy load and/or between 70-80mph. During the concern the ICP pid graph spikes and drops off, like a saw tooth pattern. An example is ICP @ 2322psi and ICP_Desired @ 3915psi with the IPR @ 85%. The truck has no issues starting - hot or cold. Like I said, this happens irregularly, not all the time but certainly under the conditions mentioned above.

I have tried a known good ICP sensor and have pulled out the IPR to see if there is anything sinister (visually going on). The customer of course is not happy as he has spent a few $$'s on this truck in the last year. Everything that has been replaced needed to be replaced but that's not always how everyone views it.

So after this long winded story my question is: a) This is a high pressure oil concern but other than dead heading the pump (which may not show me anything per se) what other diagnostic procedures could I perform to come to a conclusion - not a hypothesis. Any help would be great, thanks!

Chase · May 20, 2014

Sounds like the HPOP can't keep up, 04 would be an early pump. Definitely could be weak.

Aaron · May 20, 2014

Pump whipped I would say.

deezul · May 20, 2014

I just finished dead heading the pump and it's max pressure was just under 3300psi...

Chase · May 20, 2014

I don't remember dead head spec but it seems that 3300 is a little low.

batmantech · May 21, 2014

The spec is listed as a min which if it only achieved that then it is to low. Usually it should go above that to over 4000.

I think you may have a vgt solenoid concern. If you do a search on the 6.0 section you will find some related past concerns that may help.

Matt Saunoras · May 21, 2014

With IPR at 85% and ICP still much lower than desired I would have to say the pump is at least some of the problem. I would check the reservoir screen under the oil cooler for any contamination and put a pump in it. You know if there's nothing on the reservoir screen then the IPR screen getting punched out was likely from failing pump debris.

I have had VGT solenoids do some weird things (including a cyclical surge at moderate throttle), it helps to have a tester laying around.

deezul · May 21, 2014

Although I have had turbos and VGT solenoids cause some surging issues the pids don't lie when monitoring the data when the event occurs. There is a direct correlation between when the ICP drops off and the surge - it feels like a boat is rocking on the water. It's nothing I have ever felt before, just cruising at 70-80mph this gentle rocking and an ICP pid graph that looks like a bandsaw blade, always short of the ICP_desired pid but usually not by much, 50-200psi. Thanks for the help so far.

deezul · May 21, 2014

So according to Ford Hotline, anything over 3,000psi is acceptable for HPOP pressure when dead headed. I know a few of you guys have said pump is starting to fail, but unfortunately I really need some hard evidence to prove the replacement. I had even isolated heads, pressurised the left head and then pressurised the right and then dead headed the pump. No change in pressure really in around the mid 3500's. Here I go chasing my tail again... Will try a known good IPR and driving the truck with the ICP unplugged.

mchan68 · May 21, 2014

If air testing the high pressure oil system reveals air exiting the oil filter housing, THAT is positive evidence to condemn a high pressure oil pump.

Aaron · May 21, 2014

^^^ good point. I forgot about that.

Matt Saunoras · May 22, 2014

hmmm anything over 3000 deadheaded is good? Not in my book. I've had 3900 PSI actual ICP WOT on a healthy running truck. You're going to know it in the seat of the pants too, more ICP means more complete combustion and in turn, more power.

Bruce Amacker · May 22, 2014

My vote is for a pump, too, this should have the early pump which I don't have specs on. The later 6.0 pump builds 4700 deadheaded. I might suggest doing a LP test while driving to make sure the HP pump isn't starving, it's easier to tap the EOT than EOP if you do it, and the thread is the same as the FP test port, use an extender to make it easier.....

Good Luck!

:grin:

deezul · June 11, 2014

My concern is that this truck doesn't "stutter" when under heavy load which, I would believe it should show it's weakness, right? I can pull wot up a hill and the truck won't miss a beat but when I cruise at 80mph (truck is hot), the truck just starts stuttering, every time it stutters you can see the "blip" on the ICP pid. The ICP voltage either spikes or drops off but does not stay constant when it's "stuttering". I know this information sounds redundant, I'm just repeating myself, once again, I'm nervous about throwing a pump at it. I've checked base pressures when cruising, it's staying constant, driving with ICP unplugged does nothing for the issue.