Check engine light. Scan said cylinder 2 misfire.New plugs & wires, air filter; re-set codes. Ran fine until 55 mph Light came on & could feel misfire. At slower speed runs great
I'm worried that I need a new engine, but is not leaking oil around heads. the old plugs look like they should have. how would I do a simple test of the coil? what would be better. Have an engine rebuilt or just buy another [rebuilt] one and put it in? what is cost comparison, including labor
Cars & Trucks - Mercury - 2000 Mercury Sable LS Premium
Answers & Comments
Panic not
a misfire (code p 0302 in this case) is most likely from a problem injector ( most misfires are injectors and fuel pressure problems)
fuel pressure problems are from pressure regulators, filters or EVAP venting problems
I suggest that you have the injectors changed , cleaned and tested first
At this point I can see no reason from your statement , that there is serious engine problems
coils will fail early on from overheating component so leave that out for the present until you get a verdict on the injectors condition.
cost consideration --a couple of hundred for the injectors as against a couple of thousand for another engine
always take the cheaper option first
It dosn't sound like you need an engine ,
The oil leaking is likely valve cover gaskets make sure #2 plug wires is snapped on tight at both ends .
Then change your in line fuel filter if this fixes the engine miss fire issue change the valve cover gaskets .
yeah the design sucks. the motor is in sideways and there's all kinds of stuff in the way, which makes it hard to get to the plugs in the back.
you have to be careful in changing plugs
mitsubishi for instance use cheap plugs on the front side--- easy to get to--- and platinum plugs on the rear because plugs seldom need to be changed and the plugs at the back are almost impossible to change
note here, it is a myth that plugs need to changed on a regular basis now because the extreme high voltage doesn't burn the center electrode away like the old points and coil did ( early voltage at the plug was around 17000 volts as to efi electronics which start at around 65000 volts-- the higher the voltage the less the current used )
A high speed miss could be a coil problem , ( weak at rpms ) or injector ( Not operating from a correct pulse )
you may find an accredited auto electrician who has experience on your make of vehicle and the necessary test equipment
if not possible then test by replacement of known good items