Car ('99 auto GT) has been running rough the last few times I had it out. Don't run it much, so thought maybe it was condensation in the fuel (ran similar when I "washed" the engine bay and soaked the coils). Added some dry gas but no better.
Today I took it out again and it got much worse. Seems like it runs ok until it warms up then runs terrible. Stumbles and bad hesitation when driving. Idles, but like it's got a lumpy cam. So today it's running terrible, but I'm 10 miles from home and the MIL (Service Engine Soon) lights up for the first time. Drive home and pull a P0403 code. Searched this forum with no luck so I did a general Yahoo search and found some threads about F150's with this code being related to a #4 cylinder misfire.
Guess that's question #1: is that what a P0403 means?
Armed with this "knowledge", I decide to change the spark plug on cylinder #4. Not sure, but the plugs may be original factory (46k miles), they were Motorcraft. When I removed the coil (attached to plug) it seemed to have coolant on the spark plug end. Not soaked, but enough to make my stomach turn. I'm figuring cracked head or block... So when I finally get the guts to remove the spark plug all the way, it's not really too wet, the tip was dry. No coolant in the oil pan by inspection of the dipstick. Coolant also looks ok (visual inspection into the fill cap). I'm hoping that it was just a small leak from one of the heater hoses (cylinder #4 is closest to the firewall, passenger side, just under the heater hoses to/from the heater core).
Change the plug (Autolite 754 gapped to .054"), clear the MIL code, and take it for a test spin. Seems to run better and the MIL stays unlit. However, later I restarted the car for another test ride (to be sure and trying to find the coolant leak). This time I let the car warm up pretty well and the hesitation is back. Not terrible, but not fixed either.
Any ideas? I plan to check the coil tomorrow, maybe coolant leak damaged it? Question #2: anyone have a similar experience? Wow this got long, sorry, but I'm a bit frustrated...why just when the car is warm? Any ideas are appreciated.
Today I took it out again and it got much worse. Seems like it runs ok until it warms up then runs terrible. Stumbles and bad hesitation when driving. Idles, but like it's got a lumpy cam. So today it's running terrible, but I'm 10 miles from home and the MIL (Service Engine Soon) lights up for the first time. Drive home and pull a P0403 code. Searched this forum with no luck so I did a general Yahoo search and found some threads about F150's with this code being related to a #4 cylinder misfire.
Guess that's question #1: is that what a P0403 means?
Armed with this "knowledge", I decide to change the spark plug on cylinder #4. Not sure, but the plugs may be original factory (46k miles), they were Motorcraft. When I removed the coil (attached to plug) it seemed to have coolant on the spark plug end. Not soaked, but enough to make my stomach turn. I'm figuring cracked head or block... So when I finally get the guts to remove the spark plug all the way, it's not really too wet, the tip was dry. No coolant in the oil pan by inspection of the dipstick. Coolant also looks ok (visual inspection into the fill cap). I'm hoping that it was just a small leak from one of the heater hoses (cylinder #4 is closest to the firewall, passenger side, just under the heater hoses to/from the heater core).
Change the plug (Autolite 754 gapped to .054"), clear the MIL code, and take it for a test spin. Seems to run better and the MIL stays unlit. However, later I restarted the car for another test ride (to be sure and trying to find the coolant leak). This time I let the car warm up pretty well and the hesitation is back. Not terrible, but not fixed either.
Any ideas? I plan to check the coil tomorrow, maybe coolant leak damaged it? Question #2: anyone have a similar experience? Wow this got long, sorry, but I'm a bit frustrated...why just when the car is warm? Any ideas are appreciated.