P0087 fuel rail pressure low limp under high loads

[Jeff Paxton]

First off, thanks to everyone who contributed to this discussion. I believe it has at least some good workarounds, and likely, the real solution to the problem. I am towing a 14,500# res style 5th wheel purchased last April from Southern California. Towed it home through the Rockies and over Loveland Pass with no problems. It was still cold in the Rockies and snowing much of the trip, but warm on the flat desert of southern California/Nevada. Then in August, back over Loveland for camping, and home over Berthoud Pass. The truck did warm up climbing Loveland that time, but no codes, just needed coolant.

My truck is down right now. I am in DesMoines trying to get home to CO. We left CO in March, for work at Perry Nuclear Plant outage in NE Ohio. After outage it was off to PA for a vacation with family. The trip out there went smoothly with the late/cool spring.

We left PA June 9th. Climbing a good hill mid afternoon in western PA, I got my first check engine/limp mode and the temp gauge indicating the the coolant was warming up. Googled up the manual limp mode reset and got back on the road in an hour. Happened again after 40mins, climbing again. Did the manual reset, and decided to look for a stealership. Pulled into the next town which didn't even have a dealer, or a parts house, but did have 2 bay diesel shop for big rigs, and a mechanic who drove a '07 Dmax classic with a programmer. He came over, pulled the 87 code, reset, and said "Must've gotten dirty fuel, get a fuel filter". Off to napa. It clouded up, started to rain, got to napa, installed new filter. Made it to northern MI the next evening to visit more family, without any more trouble. Problem solved?

We left MI on the 15th stopping in Minooka, Il for the night, still no problems. Headed west in the morning hitting the hills in eastern Iowa by early afternoon. Yup, code/limp/pull over/manual reset at Coralville. Pulled off thinking "that was some really bad diesel, if it crapped up another filter that fast." Went to O'reilly's, picked up AC Delco filter, installed and back on the road in little over an hour. Hit the road and noticed check engine was OFF?? Hmmm? Drove a while, got another check engine/limp/pull over/manual reset and each time the coolant temp has climbed, once near red line. It's not the filter, I need a mechanic.

Got it into DesMoines, set up the camper at Adventureland, and took the truck to Bob Brown GMC the next morning. They did not want to hear the details. Their attitude... "Just leave, we'll figure it out and let you know." I get a call..."You need new HP fuel pump, two fuel rails, and 8 new injectors. A ceramic ball valve in the pump is failing and ruined the entire fuel system after the pump. And oh, you have a head gasket leak that we can fix while we're in there for just over $12k." Yea, I'll be getting a second opinion, and if that's the truth, a new motor. They quoted me just over $19k for the new motor. Next stop, West Side Diesel Repair.

They confirmed the HP pump diagnosis, dispelled the leaking head gasket, and agreed to replace the pump, coolant system chemical flush, fuel system clean/flush, and agreed that without one single symptom associated with injector failure presenting, fix those if/when symptoms say to.

Got the truck back first thing Friday morning. Hit the road at 11. Made it 20 mins west of DesMoines (and I was pushing/testing) and we were turning back after another manual reset. Waiting until Monday for them to resume but I am pushing the collapsed fuel line angle, and once they fix that and/or whatever else they come up with, I will be heading to a car wash to do the fuel cooler clean you all recommend, and trying again. Keep you posted....