Question: 1998 Ford F-250
Hi Vincent,
I am hoping you can assist me with a problem. I have a 1998 Ford F-250 4 x 4 with a Triton 5.4 liter V-8 and approximately 70,000 miles on it. Recently, on my way home from work, the truck started running kind of rough and I could feel a vibration in the floorboard. The problem started out as a hit and miss thing and then one night, it occurred when I was giving a friend a ride home The engine light came on at this point but it was flashing.
When I dropped my friend off, within 5 minutes the problem once again departed and the check engine light went off. I wish I could say this was the end of the problem, but the problem was right back where it left off when I went to work that night. An exception; the engine light came on, blinking at first then stayed on with no blinking.
I took the truck to AutoZone for a scan and they said the number 4 plug was fouling. So I bought a new plug and a new coil, seeing how Ford uses coil on plug technology. This was no easy job as the number 4 plug is in the back on the passenger side and is covered by a lot of wires and plugs. The truck ran ok for about 5 minutes, then resorted back to its rough running state,
I took the coil back and got a replacement and once again installed it. The truck ran fine for about 15 minutes, and back to poor state again. The truck accelerates fine but you can feel its vibration. I don't know what else to do as this should have corrected the problem. I made sure the arrows on the coil lined up right and the plug gapped between .052"-.056".
Some mechanics at work said to replace the fuel filter and put some fuel injector cleaner in it and maybe replacing the PVC valve.
Can you assist me in this endeavor please?
Thank you,
Robert Armstrong
Montgomery IL
Answer: Ford has a peculiar problem with 5.4 liter V-8's engines in 1997-1998 Ford Expedition, F-150 and F-250 LD built before 11/1/1997. Water from the A/C drain hose drips on the HO2S causing thermocycling.
To fix this you need to make up a new drain hose or add an extension to the existing drain hose. If you go to a Ford Dealer you can ask for a copy of TSB 00-1-7 dated 01-10-2000 for the detailed repair procedure.
If you would have given me the exact code number I could be certain this applies to your specific vehicle. This problem will cause either DTC P0133, P0171 or P1131 to be stored in memory.
Vincent Ciulla - Vincent Ciulla has been a professional automotive technician for over 35 years and is a certified master technician with experience in ...
