Q: when should i replace spark plugs

asked by on April 26, 2017

when should I replace spark plugs? I bought it used at 82,000 and don't think it was ever changed.

My car has 157000 miles.
My car has an automatic transmission.

Spark Plugs Replacement $113.11 - $716.47 Get a Quote

The service life of spark plugs on this vehicle is 100,000 miles. If the plugs have never been replaced, exercise caution during removal as the plug threads can get quite stuck to the head, and possibly seized, if too much time has elapsed. In fact, plugs are often serviceable past 100,000 miles, but it’s a good idea to remove them anyway to avoid having them get basically "stuck". When installing the new plugs, be sure the spark plug hole female threads are absolutely free of oil (dry) when you install the new plugs using an inch pound torque wrench. Otherwise the plug WILL be over tightened. There is other scheduled maintenance for your vehicle that may or may not have been performed. If you want to start with spark plug replacement, please use YourMechanic’s spark plug service request page and the responding mechanic will take care of the plug replacement and, as well, let you know of the rest of this vehicle’s maintenance requirements. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Do I need a brake fluid flush when I replace my brakes?
Brake fluid, like other fluids used in our vehicles, is subject to degradation over time. Brake fluid is a hydraulic and hygroscopic substance which means it absorbs moisture if left exposed to atmospheric humidity. Minute pieces of rubber can break...
When rev engine, short lag and slows to idle
You did not mention the engine you have in your truck, but I would suspect the engine turbo vane control is sticking when you rev the engine and will cause the engine to stay revved until the vanes go back...
I am having an oil leak coming from the bottom and the top of my engine, what could cause this?
Hi there. Most of the time these leaks come from the valve cover gaskets (https://www.yourmechanic.com/services/valve-cover-gasket-replacement) or the upper oil pan area (https://www.yourmechanic.com/services/oil-pan-replacement). If the leak is really small, it can be caused by a failure in the PVC system. If...
Transmission replacement - 2006 Jeep Grand Cherokee
Hello - yes, you are correct. Both the 3.7l and 6.1l Jeeps utilize the W5A580 transmission. Should be a straightforward swap. Torque converter may be different however (RPM range engagement), check your transmission supplier for details.
How many bushings are required for each control arm?
Hello - control arms (https://www.yourmechanic.com/article/how-to-buy-a-good-quality-control-arm-assembly) usually have 2 bushings, but sometimes only 1 - depends on the suspension design. If you could provide the year, make and model of the vehicle, and whether it is for the front or rear...
Temperature gauge jumping around?
Hi There, It sounds like you may have a faulty coolant temperature sensor (https://www.yourmechanic.com/services/coolant-temperature-switch-sensor-replacement). The coolant temperature sensor, is a sensor that reads the engine coolant temperature and sends a signal to the engine control module, or ECM, to control...
Fuel line pressure relief.
The fuel pressure can be relieved by disconnecting the fuel relay or inertia switch and letting engine run until it dies. Then try to crank the engine several times to make sure it is no able to start. Then you...
Hazard lights wont shut off on my 2007 Subaru Forester
Generally this is something caused by the flasher relay (https://www.yourmechanic.com/services/hazard-turn-signal-flasher-replacement) going bad. This is a small relay that allows the lights to flash based upon current flow and a resistor inside that causes them to flash. When this is faulty,...
Idle
A faulty or blown fuse in other electronically controlled systems can cause the IAC motor to malfunction, leading to a higher than normal engine idle speed. Other possible causes of a high idle include vacuum leaks, a malfunctioning throttle (throttle...

Related articles

How Long Should an Engine Last?
A car engine can last hundreds of thousands of miles. Get your oil changed often and don't ignore car warning lights to make your engine last longer.
How to Improve Your Gas Mileage
Every driver wants a fuel efficient car. Check your tire pressure, replace old spark plugs, and change your engine air filter to improve your MPG.
How To Keep Your Car From Overheating
Monitoring your coolant level, turning the A/C off in very hot weather, and regular inspections will help you avoid having an overheating car.