Would bad spark plug wires cause a check engine light?
I just changed the valve cover gasket on my car. Then when I tried to start it, it started violently shaking and the check engine light turned on. The only thing I could think is that maybe the spark plug wires broke when I took them off. Would that cause a check engine light? It's a 2002 Ford Focus ZTS with 150000 miles
My guess is that you did not put the plug wires on the right cylinder or that you unplugged a sensor and did not plug it back in yet.
HI, you could still have them on the wrong plugs if the motor is a V8 or V6 and you didn''t follow the order of the motor. On some V8 motors the driver side is 1234 and passanger side is 5678 and on some the driver side is 1357 and the passanger side is 2468. And on some #1 is on the left bank and on some #1 is on the Right bank.
So you could still have them off. That's what it sounds like anyway
You put the leads back on the wrong plugs. That's why it's misfiring and bringing up the light.
It is safe to say whatever is making the engine shake like a wet dog is responsible for the light, and I would believe the spark plugs and wires are high on the suspect list. Even a little bit of that nonsense will set the check engine light with misfire codes (P0300-P0304).
More likely you plugged the wrong wire to the wrong coil/plug
Quite possibly yes. If the outer lining of the wires is old and brittle, it would have cracked and make the spark jump out of the side and ground on the block somewhere without ever reaching the spark plug. Try getting a new wireset.
If you took the wires off, perhaps you did not put them back on correctly. There's a prescribed firing order and if the plug wires are not put on the proper spark plug it will cause a misfire resulting in violent shaking.
If you're sure the wires are properly installed it's possible the removal and flexing caused internal damage check with ohm meter… Or
you left off or broke a vacuum line or cracked the pcv valve elbow… Check the code… I've seen crossed wires give fueltrim codes not misfire, but on a four I'd think the crank sensor might sense it as such.double check everything before you toss parts at it…
Obviously, the wires length will only allow them to go to the right plug… But maybe on the wrong coilpak terminal.
If you're sure it's wired properly, get your code read for free at your nearest auto parts store. It will tell you a cylinder is misfiring. Switch the wire from that cylinder with the wire from another cylinder and read codes again. If the problem moves, then change the wire. If it stays put, then the problem is something else.
- Difference between SERVICE ENGINE SOON and CHECK ENGINE light? Is there any difference? I have a Ford Mustang 2002 and my SERVICE ENGINE SOON light is on. Does it mean something is wrong with my car? Do Mustangs also have a CHECK ENGINE light?
- My ford focus 2000 model check engine light just came on what could be the cause? My Ford focus check engine light came on when l suddenly climbed a speed breaker. What could have caused the problem more so l just bought the vehicle thought not brand new, l am in Nigeria where you don't really find expert easily to know what wrong, what can my mechanic check to clear the light.
- Is it bad to have check engine light on for too long? Trouble code P1450: Unable to bleed up fuel tank vacuum? My check engine light came on in my 2015 Ford Focus SE a couple days ago and I went to autozone to see what the problem was, and it said it was trouble code p1450 and it's unable to bleed up fuel tank vacuum, and the solution is to replace evaporative emissions. I won't have any money to go get it fixed until Christmas, which I'm supposed to be spending in Chicago and I'm driving 6 hours. Is it safe to drive 6 hours straight and wait about a week to get this fixed?
- F150 Ford, rain and humidity prevents starting. It's not the distributor or plug wires? It's not the distributor or the wires. Fuel pump is pumping? If it's already running when it's raining, it will continue to run just fine. It's definitely condensation somewhere?