jseabolt
Well-Known Member
- Joined
- July 12, 2009
- Messages
- 232
- Reaction score
- 4
- City, State
- Kingsport, Tennessee
- Year, Model & Trim Level
- 2006 Explorer Limted V8
I installed new plugs yesterday. Compared to the new plugs, the electrods on the old ones looked worn at 114K miles. The gap had increased. So I was confident new plugs maybe what the doctor ordered.
After starting the engine, it seemed to idle OK. After a 10 mile test drive it seems the engine runs worse!! How could installing new plugs cause an engine to run worse?
Symtoms:
1) If I hold the throttle around 1500 rpms at idle, the misfire is felt.
2) If I hold the speed at 45 mph (most apparant at this speed), the misfire seems to be happen every 4 or 5 seconds.
3) When this happens I hear this rumbling sound as if I hit those hash marks carved into the edge of the road to warn me I am about the run off the road.
4) RPMS actually increase a bit when this misfire occurs (shouldn't that be the opposite?)
5) misfire doesn't seem to occur when the cruise control is on (weird).
6) Still the check engine light does not kick on. I have not connected my scan tool since to see if it's throwing a code.
Does any of this sound familiar?
So I installed new plugs. What's my next step? Buy a new coil and start with cylinder #1, test drive and if this misfire doesn't go away, move the coil to the next cylinder?
If I unplug the connector on each coil, and the RPMs do not drop on that cylinder would that tell me is that cylinder is misfiring?
Still not sure if this is a random misfire or a dead coil. Assuming this is ignition related.
One thing that scares me is on one of the plugs, the neck had some slight surface rust on it. That maybe nothing to worry about. I did not notice this on any of the other plugs. Based on the overflow tank I am not seeing any lose of coolant. As if I have a bad head gasket or a leaking intake manifold.
Any tips at troubleshooting this problem? I'm thinking about just taking it to a guy I trust who owns a shop and pay he to troubleshoot it. I normally like repairing my own vehicles but I don't know if I can do this with my 1980s era diagnostic tools. I could be spinning my wheels on this for days.
After starting the engine, it seemed to idle OK. After a 10 mile test drive it seems the engine runs worse!! How could installing new plugs cause an engine to run worse?
Symtoms:
1) If I hold the throttle around 1500 rpms at idle, the misfire is felt.
2) If I hold the speed at 45 mph (most apparant at this speed), the misfire seems to be happen every 4 or 5 seconds.
3) When this happens I hear this rumbling sound as if I hit those hash marks carved into the edge of the road to warn me I am about the run off the road.
4) RPMS actually increase a bit when this misfire occurs (shouldn't that be the opposite?)
5) misfire doesn't seem to occur when the cruise control is on (weird).
6) Still the check engine light does not kick on. I have not connected my scan tool since to see if it's throwing a code.
Does any of this sound familiar?
So I installed new plugs. What's my next step? Buy a new coil and start with cylinder #1, test drive and if this misfire doesn't go away, move the coil to the next cylinder?
If I unplug the connector on each coil, and the RPMs do not drop on that cylinder would that tell me is that cylinder is misfiring?
Still not sure if this is a random misfire or a dead coil. Assuming this is ignition related.
One thing that scares me is on one of the plugs, the neck had some slight surface rust on it. That maybe nothing to worry about. I did not notice this on any of the other plugs. Based on the overflow tank I am not seeing any lose of coolant. As if I have a bad head gasket or a leaking intake manifold.
Any tips at troubleshooting this problem? I'm thinking about just taking it to a guy I trust who owns a shop and pay he to troubleshoot it. I normally like repairing my own vehicles but I don't know if I can do this with my 1980s era diagnostic tools. I could be spinning my wheels on this for days.