3 Best Glow Plugs for Duramax - Buyer's Guide & FAQ (2023)

by · Automotive Expert

If you are a lucky owner of a diesel engine vehicle, I bet you’d be interested in my outline of best glow plugs. I’d like to share with you my expertise and help you make the right choice.

I believe you’ve already faced the problem when in cold temperatures it takes all your efforts and lots of your precious time to start your diesel engine. That happens because the mass of the cylinder block and cylinder head absorb the heat of compression and restrain ignition. To avoid this issue the glow plugs have been used for years.

Why you can trust me?I accept nothing from product manufacturers. Never. Here — only unbiased reviews and my opinion. I only earn commission from Amazon

I recommend:

our pick

ACDelco 9G Professional

A trusted quality and perfect service

The product is really worth buying due to its high quality, long lasting performance and it has full range of reaches which matches requirement in wide variety of applications

best value

ACDelco 62G Professional

Performance exceeds all your expectations

I would highly recommend this product since the advantages overtake the only disadvantage which is affordability. The product is good value for money. Don’t cheap out and it will pay you back.



Environmentally friendly and inexpensive choice

This product is really affordable and at the same time provides good quality and service. It has a reliable start and very short pre-heating time. I recommend this item for its safety as well.

Today's market has a rich assortment of glow plugs for various car models, years and other criteria to consider. So when it comes to replacing your glow plug, I believe you get frustrated since you are scared of making a wrong choice or being overcharged for a low quality product.

In this article I selected in my opinion best glow plugs. They have a decent reputation and trusted quality. I highly recommend all of them. Just read through to see what is proper for you in particular!

How often do I need to change glow plugs?

There is no particular durability period for glow plugs, however, it is recommended that they should last for as long as 100,000 miles. They will gradually get worse due to wear and tear over this period. The good thing about glow plugs is that they are incredibly long lasting. What’s more, they are the most cost-effective car parts to replace.

Table of Best Glow Plugs for Duramax

NameOur ratingrequired yearsetpriceShops
ACDelco 9G Professional
ACDelco 62G Professional

swipe left to see more

How I decided

models considered
hours spend
experts interviewed

Best Glow Plugs for Duramax

ACDelco 9G Professional

Our rating:

These glow plugs will do a good service for you and your car. They are designed to provide diesel engines with the heat which they need for cold starts. These glow plugs manage ignition in all cylinders and enhance throttle response. You definitely won’t be able to resist temptation to try these ones on your vehicle. And once you’ve installed them, you won’t ever regret. These glow plugs are of a really trusted quality.

AcDelco 9G is incredibly easy to install. You won’t need any special tools or professional help to do that. A standard kit is all you need.

However, you better keep in mind that it can be a bit tough to remove them, in case you need it. That’s an only challenge you should be ready for.

AcDelco glow plugs stand out as being dependable and providing long-lasting performance.

The advantage over the other plugs is their feature of cutting down exhaust emissions. The price is also competitive. These plugs will meet all your needs.

Key features:

  • GN-type regulating coil
  • self-regulating to manage electrical flow from the battery as temperatures rise to avoid overheating, produced to restore your vehicle’s ignition system
  • a wide range of reaches - from 21 mm to 40 mm
  • provides the best quality at a great price
  • lower emissions

Product score:

  • performance (8/10)
  • quality (9/10)
  • price (7/10)


  • easy to install
  • durability
  • high quality
  • difficult to remove
  • price

ACDelco 62G Professional

Our rating:

ACDelco 62G Professional glow plugs will take all your doubts away since the product is trustworthy and timeless. It meets highest quality standards requirements and you can be sure that it will serve you for a long time causing no troubles at all.

If you come across the difficulty of starting up your car in cold temperatures, then ACDelco 62G Professional is exactly what you have to purchase as soon as possible. Due to new materials and advanced technologies the pre-heating time is less than 5 seconds. Thus it will provide you with a much faster engine start-up than any other glow plug in the market.

ACDelco 62G Professional can function under higher voltages than other glow plugs. It resists corrosion and vibration as well as protects coils from exhaust gas damage.

These glow plugs are a typical example of an experienced engineering product, so with manufacturing these plugs ACDelco have achieved really high quality standards and they will exceed any of your expectations.

What’s more, meticulous design and precise engineering provide you with a really easy installation which can be managed by any savvy car user.

Key features:

  • GN-type regulating coil
  • self-regulating to manage electrical flow from the battery as temperatures rise to avoid overheating
  • produced to restore your vehicle’s ignition system
  • wide range of reaches - from 21 mm to 40 mm
  • maintains ignition in all cylinders
  • improves throttle response and reduces diesel emissions
  • 12-month/12,000-Mile Limited Warranty

Product score:

  • performance (7/10)
  • quality (8/10)
  • price (8/10)


  • high quality
  • 12 month warranty
  • durability
  • easy installation
  • none


Our rating:

This product will attract your interest straightaway for many reasons. Firstly, due to its quality and precise engineering. Secondly, these glow plugs can be used for post-heating which means they are environmentally friendly and produce up to 40% fewer emissions during the phase of warm-up.

Moostore glow plugs have extremely short pre-heating time.

They claim to start-up your engine in less than 3 seconds. What’s more, they will start even at extreme temperatures, even at -30 °C! This is an obvious advantage, I believe.

This product will provide you with a quieter engine running and it will protect your engine during starting up.

It resists corrosion and vibration, so it will have durable performance and long-lasting service.

Installation won’t take much of your time. Following some video instruction or manual guide you can replace your old glow plugs with these ones without any trouble. You won’t need any professional help or to be well-equipped to manage it.

Be aware that these glow plugs can be easily damaged during transportation and there are a lot of complaints about broken items. The other thing is if you were planning to replace AC Delco 9G with this product, don’t have really high expectations.

Key features:

  • fast start-up
  • extremely short pre-heating time
  • environmentally friendly
  • protects engine
  • starts at extreme temperatures

Product score:

  • performance (7/10)
  • quality (6/10)
  • price (9/10)


  • faster starts
  • much lower emissions
  • reliable starting
  • can be misfit

Best Glow Plugs for Duramax Buying Guide & FAQ

How to install glow plugs?

Many of us have concerns whether to replace glow plugs by themselves or better address a professional mechanic to do it. The answer is pretty simple. If you have the tools, you don’t need to pay extra labor costs and you can do it yourself. If you are still not sure you can do it correctly, be ready to be charged between 90 $ to 200$ for glow plugs replacement.

Anyway the process is pretty simple. I can assure you that you are able to do it yourself. I’d recommend you to spray the plugs with penetrating oil a few days before you remove them. Put a little anti-seize on the glow plug threads.

Check the video

How do glow plugs affect power?

They can make a significant effect on power. In case glow plug fails, they will not provide the additional heat that helps diesel combustion. As a result it causes the engine to experience misfires. The misfires in their turn may cause a loss in power, acceleration, and even fuel efficiency.

Best Glow Plugs for Duramax FAQ

Q: Does it make a difference which glow plugs I buy?

Yes, it definitely does. Nowadays there are a lot of low quality cheap glow plugs or what can be worse fake copies of famous brands glow plugs. It does matter what quality glow plug you install since it can heavily damage your engine.

Cheap aftermarket glow plugs can swell and make the removal impossible. Moreover, the tip can swell and break off in the cylinder. It can result in damage of the piston, cylinder, valve and head, which can make you have a costly engine rebuild. If you do care of your vehicle and your safety as well, don’t hesitate to buy a more expensive but reliable set of plugs. This will help you save money as a result and won’t cause you any further troubles with your car.

Q: What are some symptoms of bad glow plugs?

Of course, to spot the problems with your glow plugs is not that much difficult. You will feel it straightaway. Thus if you have a slow starting or there is a complete failure to start, they are clear signs of a glow plug malfunction.

If you have a four cylinder, one damaged glow plug will cause slight hard starting and a miss. Two plugs out of order will cause a very hard start and very rough operation. Three bad plugs make the car almost impossible to start and keep running.

If we are talking about larger engines, the story is the same.

If your vehicle starts alright if you plug in the block heater overnight, but will not start if you do not, then you most probably have a glow plug issue unless your engine has very low compression.

Q: How do I check my glow plugs?

Testing glow plugs is as simple as that! You can do it even if you are a non-experienced driver!

You need to start with disconnecting the wires from each of your glow plugs. Then, hook the clip of your 12 volt test light to the battery POSITIVE terminal.

After that touch the probe of your test light to the terminal of the glow plug itself (NOT the wiring harness!). Any glow plugs that do not light the test light is bad.

There is one more way to test your plugs –use an ohmmeter – Again, disconnect all wires from each glow plug to prevent parallel paths. The measure resistance between ground the terminal of each glow plug.

Any glow plug that indicates infinity or more than a few ohms is bad. The other way is an ammeter – measure the current draw of each plug individually – using this method, you can catch glow plugs with slightly low current draw that are starting to fail.


As you can see all above presented glow plugs are worth considering. They have been proven as decent products which can serve for years. These glow plugs help your engine start within a few seconds and at the same time decrease emissions. If you had any doubts before, I am sure now you know what to pick out of the wide range in the market. Don’t cheap out, believe me, low quality glow plugs will cause only headache and will demonstrate their flaws sooner than you can even think of. So as a result you will have to pay double price. In these cases the prices are reasonable and the products are good value for money.

If you have doubts as for being able to install them without anyone’s assistance, don’t worry, you definitely can! You can use youtube link below to check if you are doing the right things and read some tips below in our Buyer’s guide.

If you pick one of these glow plugs, you will never regret it!


  1. How to Test Glow Plugs, wikihow
  2. 5 Symptoms of a Bad Glow Plug (and Replacement Cost), cartreatments
  3. Glow Plug Replacement, forum