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Tips on LB7 Duramax Glow Plugs Delete, Replacement, Location

LB7 Duramax Glow Plugs

About lb7 glow plug

What does it mean by LB7? LB7 is an RPO code for 2001-2004 model year Duramax engines. Some other common RPO codes of Duramax engines are LLY, LBZ, LMM, LGH, etc. As all the Duramax engines are diesel-powered engines, they use glow plugs instead of spark plugs. Similarly, LB7 also uses glow plugs.

LB7 Duramax Glow Plug

In addition, the LB7 Duramax engine is a 6.6L V8 engine. It means it has eight cylinders. To determine the number of glow plugs for an engine, you need to know the number of cylinders of that engine. As LB7 Duramax is an eight-cylinder engine, it needs eight glow plugs in case of a full replacement.  Check LMM Duramax Glow Plugs and LMM Torque Specs.

LB7 glow plug delete

Will it affect the engine if you delete the glow plugs of your LB7 Duramax? Well, it depends. Primarily, we can say no, it won’t affect the engine. Because a diesel engine doesn’t depend on glow plugs solely. Glow plugs merely help the engine for starting up. Especially, in the cold weather.

Mainly a diesel engine depends on compression to start up. So, you won’t be in any problems during the summer. But in winter, you will face hard times starting the engine.

How To Remove Broken Lb7 Glow Plug Duramax

Once you have located the glow plug, you can begin to remove it using the following steps:

  1. Disconnect the battery and the power to the engine.
  2. Locate and remove the glow plug wire. Unscrew the nut holding the wire to the plug and gently pull the wire from the glow plug.
  3. Remove the broken LB7 Glow Plug Duramax with a spark plug socket.
  4. Clean the area around the spark plug to ensure no dirt, oil, or debris interfere with installing the new glow plug.
  5. Grease the threads of the new glow plug before installing it.
  6. Install the new glow plug into the cylinder head and tighten it to specifications.
  7. Reconnect the spark plug wire.
  8. Reattach the battery and reconnect the power to the engine.

How Do You Test Lb7 Glow Plugs?

Once all the plugs are removed, turn the multimeter to the ohm setting. The ohm setting displays the resistance of the plug by connecting the probes to both core elements.

If the reading falls within 0.3-0.8 ohms, your glow plug is in proper working order. However, if the reading comes out lower or higher than this range, the glow plug has a higher resistance and should be replaced.

How Do I Know If My Glow Plugs Are Bad Duramax?

  1. Hard starting: A bad glow plug can significantly reduce the ability of the engine to start up. If your engine is having a hard time starting, it could be a sign that your glow plugs are malfunctioning.
  2. Engine misfiring: When a single cylinder is cold and has a malfunctioning glow plug, it can cause the engine to misfire. This can also be caused by a weak battery or a problem with the fuel injection pump.
  3. Rough idling: If your engine is running rough, it could be a sign that your glow plugs are malfunctioning.
  4. Reduced fuel efficiency: After the engine has warmed up and running properly, a malfunctioning glow plug can cause a significant drop in fuel efficiency.
  5. Smoke: Smoke from the exhaust pipe is never a good sign and if you are seeing smoke from your Duramax Diesel, it could mean that something is wrong with your glow plugs.

How Many Glow Plugs Are In An Lb7?

For an LB7 engine, the number of glow plugs you need is 8 – so make sure that your replacement engine parts are up to this number to keep your engine running as it should.

Will New Glow Plugs Improve Performance?

Yes, they can. While the effects won’t be as noticeable as those offered by spark plug replacement or engine tuning, a quality set of glow plugs will still make a measurable contribution to a car’s performance.

How Long Do Lb7 Glow Plugs Last?

In most cases, the plugs should last up to 100,000 miles, though occasionally, some need replacing before that.

How do I Know if My LB7 is Duramax?

Fortunately, it’s easy to determine whether or not your truck is a Duramax. The easiest way to do this is to simply look up the truck’s VIN (Vehicle Identification Number) and search through a specialized VIN decoder. This should tell you what kind of engine your truck is equipped with.

LB7 glow plug replacement

When will you need the glow plug replacement on your LB7 Duramax? First things first. Surprisingly, Want to know the major difference between spark plugs and glow plugs? You don’t need to replace the glow plugs regularly like the spark plugs. You have to change the glow plugs only when you see the symptoms and are sure of any damage to the glow plugs.

You can either change only the faulty ones or the whole set. It is up to you. But we recommend that if more than three or four spark plugs get damaged, replace all eight spark plugs. Otherwise, replacing the whole set won’t be necessary.

Removing swollen glow plug -lb7 Duramax

How to change glow plugs on lb7 Duramax

Changing the glow plugs on LB7 Duramax is a bit difficult. You have to soak them for a couple of days to finish the first step. To safely change the glow plugs, you should not use too much muscle power. If the glow plugs break, you are in a world of trouble. After soaking and removing the older plugs, you are all set to rock with the new glow plugs.

LB7 glow plug location

LB7 has eight glow plugs on each of its cylinders. That means they are in different locations. You can access the glow plugs in different ways. Experts suggest that you remove the wheel fender liners to get to the glow plugs. However, some of the mechanics also stated that you can also reach the glow plugs from the top.

LB7 glow plug removal tool

Although it is a little tough job to remove the glow plugs of LB7 Duramax, you can do it with the right tools and guidelines. You should never go for removal with some unknown tools. It can damage the cylinder heads and break the glow plugs. If you don’t find the right tool in any nearby stores, no worries. There are plenty of good products online. Go and pick the right fit.

LB7 glow plug relay      

If the glow plug relay of LB7 Duramax goes bad, you need to change that too. But how do you know that the glow plug relay has gone bad? And how do you find the glow plug relay?

LB7 Glow Plug Relay

Whenever you see codes related to glow plug problems, there is a chance of glow plug relay going bad too. That’s how you know it. And you are going to find it in a black box behind the valve cover on the driver’s side.

LB7 glow plug strap

You may need to change the glow plug straps of your LB7 Duramax too whenever you are going for a glow plug replacement. If the straps get corroded, it will be better to change them to get better capacity at carrying current. You can either buy only the straps or can buy a package with glow plugs, relay, and straps. Both will do just fine.

LB7 glow plug module

We know the functions of glow plugs already. They heat up to help the engine getting started. But how the overall control is done? Here come our glow plugs control module.

If you see any codes in your LB7 related to the glow plugs problem, make sure to check whether the glow plugs control module is okay or not. If that is not the case, you are relieved from spending a lot of money.

LBZ glow plug part number

Finding the exact part number for glow plugs on LBZ might be a problem. Don’t worry. We have got you covered in this area also. The glow plug part number for GM is #97364968 and is 61G.

How much does it cost to replace glow plugs on a Duramax?

In total, you need to pay around $250 to $400 for the replacement of the glow plugs on your Duramax engine. $100-$200 for the labor cost and $150-$200 for the glow plugs (full set). Obviously, you can eliminate the labor cost if you have the right tools and expertise.

Best glow plugs for lb7 Duramax         

The best glow plugs for LB7 Duramax are-

  1. Duramax LB7 Glow Plug Kit
  2. Wellman Glow Plugs Diesel Fast Start (Set of 8)
  3. Set of New Glow Plug 2001-2005 for Chevy GMC 6.6L Duramax LB7 & Early Build LLY

Does LB7 have glow plugs?

Yes, it does. As LB7 Duramax is a diesel engine, it uses glow plugs at place of spark plugs to help the engine start-up. And as the engine is a V8 engine and has 8 cylinders, it needs 8 glow plugs to function properly.


To find the origin of LB7 Duramax engines, you have to go back as far as 2001. 20 years back from now on. For this reason, it is quite hard to get the right information related to this engine’s parts. We have tried to do the hard part i.e. research for you, at our best so that you can find the information easily.

Even though glow plugs are not mandatory for your vehicle’s engine, they play quite a role in cold weather. That is why you need to maintain and look out for any problems related to these parts. And if you find one, try to fix it carefully. If you have any doubts, don’t hesitate to go to the mechanics. In that way, you and your vehicle both will remain fine.

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