Spark plug replacement?

Dan

Replace the plugs now! They're cheap and should have been done long ago, coils are not needed unless new plugs don't resolve a misfire. The hesitation you're feeling is the primary reason catalytic converters fail - simple lack of maintenance.

Anonymous

A year, make and model would be nice. Replace the plugs. Issue does not go away, car has other issues like a bad idle air control valve or throttle body. And it seems you are NOT taking care of your vehicle. You are likely to have many other problems in the future.

thebax2006

C'mon...what kind of vehicle is it? I'd just replace the spark plugs first since you know they are way past being needed. If you have a Honda or Acura the valves need adjusting every 60,000 miles or the motor will have the same problem you're describing.

don r

You will see after removing the old plugs how bad they are worn out. Very likely plugs are only what you need.

JJ

Certainly the plugs are past due so just do them first .

Bertsta

Before spending money, gap the old plugs. If that doesn't work, try new plugs, the cheap ones will do. If that doesn't fix things, then investigate some more. Don't buy stuff unless it is cheap and/or you can fix it yourself, or you know you need to.

dtstellwagen

If you are driving a V8 Ford then I would seriously consider changing the coils too, they are near end of life, you can get a set for $30. Otherwise it will cost more for diagnostics and replacement when the first one fails.

Evil C

Without knowing what kind of car you drive, it is difficult to give you accurate advice. Not every car has the same engine control systems. But, to broadly explain what your issue could be, your description leads me to believe your issue is not with the spark plugs, but with the throttle body and idle control valve. If your car is old enough to still have a cable operated throttle body, locate the idle control valve (ICV), remove it from the throttle body, and clean it using a nylon or brass wire brush and carburetor cleaner until you remove all the carbon buildup. It would also help to spray and brush out the cavity in which the ICV lives. If your car has an electronic throttle body, the throttle body itself needs to be removed and cleaned. In either case, after cleaning, allow the parts to dry out for about 30 minutes before reinstalling on the vehicle, or else any vapor from the cleaner will cause an initial hard start. As for the spark plugs, you should probably change them just for preventative maintenance reasons, because 150k miles on a set of plugs is quite a lot. Even iridium plugs are only designed to last around 100k miles. And only focus on the coils if nothing else helps, because the coils can get expensive, and should only be replaced if they test bad. If your check engine light is on, have your vehicle scanned if you do not have a scan tool or know how to decipher trouble codes. That can also be very helpful in narrowing down your problem.

STEVEN F

This is as good a time as any to have the coils tested. I would replace the plug wires as well as the plugs if they have gone 150,000 miles.

arther

if the coils are under the inlet manifold Id be replacing while the manifold is off to get at the plugs? What does the book in the glove box say about replacing them?