Greetings fellow Expedition owners/mechanics/stakeholders:
I’ve got a tricky issue with my 2003 EB 5.4L V8. It is one of the trickiest I’ve dealt with in my 20 years of owning it (sole owner). Started in March. I’d be most grateful in someone can spend an extra few minutes to read the details and provide a few ideas.
Is there something my shop(s) and me are missing?
In March started having bucking/missing engine. Assumed I was having another coil pack go out. Coils in the Expedition are flakey. Replaced almost all of them over the 212,000 miles, but been several years since the last coil got replaced. Took it to a shop I’ve been using the last year when the SES light came on in March. They primarily do AC work – which is how I “met them” a year ago when they replaced the clutch and did some AC work on the Expedition. Since then they replaced my intake manifold, central junction box, and fixed a vacuum leak. Not knowing how extensive their diagnostics are beyond just pulling basic codes, I took to them in March when the SES light came on.
So… they did get P0357 but did NOT believe it was any coil. They said it might be internal timing going bad on the engine. Self-stating they do not really like getting in to all the mystery oils, they did change the oil and filter after running BG EPR (Engine Performance Restoration) because they stated they have had positive experiences on other customer vehicles with BG EPR removing sludge and restoring rough running engines. I am not one to skip an oil change in 20 years. But the BG EPR and oil change seemed to work. For about a month, the engine ran smooth.
…Then April came. Back comes the roughness again. So, I did my own BG EPR (two cans) ran for 20 minutes, then had a quick change immediately change the oil/filter. Did not really help much this time. SES light came on and stayed on. My basic $20 Ancel code reader shows same code P0357.
But this time, elected to go a local shop in the city, recommended by another friend, for whom claims they have the expensive $5K plus diagnostic computer. They confirmed P0357. Replaced coil #7 last week. Sent me on my way. Engine then ran GREAT for three days, all the way to and through parking at the airport for a three-day trip. Best three day stretch of engine operation in many weeks.
Flew home three days later, and IMMEDIATELY on startup the engine is running rough again, and the SES light this time starts flashing. The next day – Tuesday May 30 took it back to the same shop that replaced coil #7, after I pulled codes on my Ancel. My cheap Ancel said I had P0303 cylinder #3 misfire. But the shop Tuesday said their $5K+ computer said code P0306 cylinder #6 misfire. They replaced coil #6. All coils BTW replaced with OEM DG508….. They test drove several miles. All good. I drove it home several miles. All good. Then wife drives its several hours later when I am gone. She said the engine SHUT OFF at the intersection near our house sitting at a light. She was able to restart. But the rough running was back.
I got home late Tuesday night. Can confirm it was running rough yet again. My Ancel has no active code, but it is showing a pending code of P0308 cylinder #8 misfire. I drove it several miles with engine missing but otherwise driveable with good power. The engine never cut off on me. The SES light occasionally blinks then turns off. BTW, badgering the shop if their $5K+ computer shows misfires at the cylinder level. Last week they said it showed misfires galore but ONLY on cylinder #7 until coil #7 replaced. Tuesday they said it showed misfires but ONLY on cylinder #6.
… I’ve had to replace in years past two coils at one time, but never three or more… But any guesses as to what is going on…. Bad run of three coils in a very short period? Something else?
BTW, all eight plugs replaced in December 2019 at ~160,000 miles.
Thanks so much,
Todd
I’ve got a tricky issue with my 2003 EB 5.4L V8. It is one of the trickiest I’ve dealt with in my 20 years of owning it (sole owner). Started in March. I’d be most grateful in someone can spend an extra few minutes to read the details and provide a few ideas.
Is there something my shop(s) and me are missing?
In March started having bucking/missing engine. Assumed I was having another coil pack go out. Coils in the Expedition are flakey. Replaced almost all of them over the 212,000 miles, but been several years since the last coil got replaced. Took it to a shop I’ve been using the last year when the SES light came on in March. They primarily do AC work – which is how I “met them” a year ago when they replaced the clutch and did some AC work on the Expedition. Since then they replaced my intake manifold, central junction box, and fixed a vacuum leak. Not knowing how extensive their diagnostics are beyond just pulling basic codes, I took to them in March when the SES light came on.
So… they did get P0357 but did NOT believe it was any coil. They said it might be internal timing going bad on the engine. Self-stating they do not really like getting in to all the mystery oils, they did change the oil and filter after running BG EPR (Engine Performance Restoration) because they stated they have had positive experiences on other customer vehicles with BG EPR removing sludge and restoring rough running engines. I am not one to skip an oil change in 20 years. But the BG EPR and oil change seemed to work. For about a month, the engine ran smooth.
…Then April came. Back comes the roughness again. So, I did my own BG EPR (two cans) ran for 20 minutes, then had a quick change immediately change the oil/filter. Did not really help much this time. SES light came on and stayed on. My basic $20 Ancel code reader shows same code P0357.
But this time, elected to go a local shop in the city, recommended by another friend, for whom claims they have the expensive $5K plus diagnostic computer. They confirmed P0357. Replaced coil #7 last week. Sent me on my way. Engine then ran GREAT for three days, all the way to and through parking at the airport for a three-day trip. Best three day stretch of engine operation in many weeks.
Flew home three days later, and IMMEDIATELY on startup the engine is running rough again, and the SES light this time starts flashing. The next day – Tuesday May 30 took it back to the same shop that replaced coil #7, after I pulled codes on my Ancel. My cheap Ancel said I had P0303 cylinder #3 misfire. But the shop Tuesday said their $5K+ computer said code P0306 cylinder #6 misfire. They replaced coil #6. All coils BTW replaced with OEM DG508….. They test drove several miles. All good. I drove it home several miles. All good. Then wife drives its several hours later when I am gone. She said the engine SHUT OFF at the intersection near our house sitting at a light. She was able to restart. But the rough running was back.
I got home late Tuesday night. Can confirm it was running rough yet again. My Ancel has no active code, but it is showing a pending code of P0308 cylinder #8 misfire. I drove it several miles with engine missing but otherwise driveable with good power. The engine never cut off on me. The SES light occasionally blinks then turns off. BTW, badgering the shop if their $5K+ computer shows misfires at the cylinder level. Last week they said it showed misfires galore but ONLY on cylinder #7 until coil #7 replaced. Tuesday they said it showed misfires but ONLY on cylinder #6.
… I’ve had to replace in years past two coils at one time, but never three or more… But any guesses as to what is going on…. Bad run of three coils in a very short period? Something else?
BTW, all eight plugs replaced in December 2019 at ~160,000 miles.
Thanks so much,
Todd