Find Out: How to tighten spark plug without Torque Wrench?

How to Tighten Spark Plug without Torque Wrench

Do you remember how much you paid for an auto repairer to tighten the spark plug the last time? It usually costs around $100 or a bit less. What if you can do it yourself even if you don’t have a torque wrench?

Sounds weird, right?

Spark plug requires a torque wrench to tighten them as manufacturers have a specific amount of torque. However, you can also hand-tighten it if you don’t have a torque wrench around.

This article will give you step-by-step guidelines on how to tighten the spark plug without a torque wrench in a proper way.

Types of Spark Plugs

There are several types of spark plugs with different lengths, thread reach, thread type, and heat range. They can be generalized into two types; gasket plugs and tapered plugs.

1. Gasket Type

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These spark plugs have a washer at the threaded end. Also referred to as a crush washer, it deforms as the spark plug is tightened into its slot, creating a gas seal between the plug and the cylinder head.

2. Tapered Type

Tapered Type Spark Plug
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As the name suggests, tapered plugs have a flat surface, which requires less torque to tighten than plugs with a gasket.

How to Tighten a Spark Plug without Torque Wrench?


Before taking out a spark plug, removing dirt and oil around its slot is good to keep the inside clean. If you are getting new spark plugs, make sure to use the factory-recommended plug type. 

You can tighten a spark plug with the following steps –

  1. Screw the plug into its socket by hand until it sits.
  2. Tighten as far as it goes. But be careful not to over-tighten it. Usually, around a half turn after the plug bottoms out will be enough.
  3. Check if you can unscrew the plug with a little force. If not, the spark plug has been installed properly, or you have to tighten it again.

The process is the same for tapered plugs, but it does not have to be tightened as much. Be careful not to over-tighten a plug as it could damage the threading and get stuck in its slot.


What happens if spark plugs are loose?

A loose spark plug may cause overheating and lead to pre-ignition and misfire issues, proving fatal for the engine. Therefore, make sure to tighten the spark plugs properly.

How long should spark plugs last?

Generally, a spark plug should last up to 100,000 miles.

Do you need a torque wrench for spark plugs?

Spark plugs have their respective torque values, mainly to prevent over-tightening. Although using a torque wrench is not required, you can tighten spark plugs correctly by using one.

How tight should spark plugs be?

It is best to refer to a spark plug torque chart but generally, spark plugs should usually be tightened until they sit firmly in their slots.


Fixing your own car is probably one of the most satisfying tasks. While it does not require a lot of expertise, you can also save some bucks by not visiting a mechanic.

You should now have a clear idea of tightening the spark plug without a torque wrench. Best of luck!

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