6.7 Cummins Grid Heater Problems (Bolt Failure and Fix)

Watch out for the hype. There is a guy on YouTube that is making a lot of money hyping this problem and his solutions to it. He may be overstating the situation to make money. It is best to get your information from a trusted mechanic than a YouTube video.

The word is that there is a single bolt that can come loose or be sheared off by corrosion on the grid heater. When this happens, the bolt piece can fall into the intake and make its way to the cylinder causing thousands of dollars in damage to the engine. There may be a solution.

To learn more about this problem, just continue to read our article. It goes beyond the hype to get the whole story. Take a few minutes to see how this information can help you make the right repair decisions and keep your 6.7 Cummins intact.

What Does The Grid Heater do on 6.7 Cummins?


The process of igniting diesel sounds more complicated than it really is. When the piston moves away from the inlet valve, fresh air is let into the cylinder. When full, the inlet closes cutting off the air supply.

When the piston returns to the inlet valves, it compresses that air to about 1/20th of its original size. At this point, diesel fuel is injected into the cylinder which ignites the fuel-air combination. The outlet valve ones and lets the exhaust out preparing for the cycle to repeat itself.

That is the basic diesel operation. The grid heater is a device that heats the air as it passes by it. This device sits on top of the main manifold and makes sure the air is hot enough to ignite once the diesel fuel is added to the cylinder.

This device is supposed to be a starter aid when winter and cold temperatures hit. It is said that your vehicle will start on the first try when your engine has this device on it.

The grid heater is an engine starter device that may replace glow plugs. Everyone is familiar with glow plugs.

The Difference Between Glow Plugs And a Grid Heater

Almost all early diesel engines were made with glow plugs. Their purpose was to help the diesel engine start. The glow plug looks a little like a spark plug and it can heat up to some very high temperatures.

You can find the glow plug in all direct injection diesel engines and their job is to heat the diesel fuel and cause ignition. To activate the glow plug you usually have to turn the key to the start position and wait for the indicator light to go out.

Once it goes out, it is safe to start your engine. Usually, if the glow plugs are still good, your engine will start the first time you try. While the glow plugs and the grid heater do the same thing, they heat different elements.

The glow plugs heat the fuel while the grid heater heats the air. The result is the same and when these parts are functioning well, you should have no trouble starting your diesel engine.

The other difference is that there is only one grid heater on a diesel engine, while you may have 4 to 8 glow plugs depending on the size of the diesel engine in your vehicle.

Glow plugs do not cost that much to replace whereas the grid heater may be very expensive to repair or replace.

6.7 Cummins Grid Heater Problems


There is a recall for over 300,000 Dodge RAM heavy-duty trucks made between 2021 and 2023. The recall is about one of the grid heater parts called the intake heater grid relay.

This part seems to be vulnerable to overheating and may start a fire even with the engine turned off. You can read about this recall at this link. The notices were sent out in March of this year and if you have not received yours, contact the company or use the links on that website page.

That is just one problem that comes with this device. There are two major ones which we will leave one for the next section to discuss. The one we will discuss here will also involve the relay but we are focusing on the wire from the solenoid to the grid heater.

It may not be the relay that is totally at fault as the wire between those two parts also overheats and can melt. Most drivers notice it when they turn the key and see smoke coming from their engine compartment.

The source of this problem is the extreme current being sent through the wires from the battery to the grid heater. There is more than one wire and one or all can melt. If they do, you can’t start your vehicle without a direct jump from the battery to the grid heater.

The grid heater won’t work on its own until you replace those wires. The problem with this fix is that the overheated wires may have damaged the relay as well as the solenoid. You may have to replace those two parts at the same time even if it means just being on the safe side of the repair.

6.7 Cummins Grid Heater Bolt Failure

This is the second major problem that is associated with this grid heater device. it is often called the killer bolt issue and it achieved that label and reputation because it can kill a diesel motor.

The bolt in question is located on the lower side of the grid which means if it does melt or falls off due to corrosion, it will fall into the manifold. When it is sucked into the engine, you will lose a cylinder, or piston and damage other essential parts.

Unfortunately, this was the same problem with the 5.9L engine some Dodge Ram trucks have under the hood. Why it was not fixed for the 6.9 motor is anyone’s guess.

The source of the problem is the 200 amps the battery sends to the solenoid and eventually to the grid heater. This is so hot that the insulation on the wires is melted and in turn, melts the metal nearby. That includes melting the killer bolt.

All this debris falls into the engine which costs approx., $10,000 to replace it. The good news with this killer bolt issue is that it does not happen to everyone. It is supposed to be a rare occurrence but if you do not want it happening to you, you can go with an after-market manifold that does not use a grid heater.

These after-market manifolds use a coil heater instead of a grid heater solving the killer bolt problem. This is a lot cheaper option than towing your vehicle to a repair shop.

One repair shop quoted a $30,000 price tag while another simply replaced the piston, rings, rods, replace the turbo, and possibly the head for $14,000. Be careful of the repair shops.

How do You Check a Grid Heater Bolt?


There is a simple procedure you can use called the jiggle test to check your grid heater bolt. There is a little bolt holding a lead that goes directly to the battery. It is located next to the fuel rail. It is not hard to reach and you should be able to get your hand to the lead without too much trouble.

Once your hand is next to the lead, lightly grab the lead in a safe spot and jiggle it. If you can jiggle the lead and the bolt, it means that the bolt on the underside of the connection is coming loose, melted, or corrosion has taken its toll.

The word of warning that comes with this test is, if the bolt jiggles, do not drive your truck. Have it towed to the nearest trustworthy repair shop and let them handle the repair.

If you drive it you are increasing your chances that the loose end of the bolt will fall into the manifold and kill your motor. The towing and repair costs are far cheaper than any repair cost after the bolt falls into your engine.

6.7 Cummins Grid Heater Bolt Fix

There are a lot of ‘fixes’ suggested on different Cummins owner’s forum threads and most seem to lead back to the Banks YouTube videos and his products.

Before we get to those, there is one simple fix that can be done. If you catch it in time, you may only have to replace the wires and the bolt. This may not permanently solve the problem as the excessive current is still being sent out from the battery.

But it protects your engine until you can find a permanent fix. One repair we already mentioned and that is replacing the stock manifold and grid heater with an after-market manifold that uses a coil heater.

It too is a simple fix and should permanently solve this issue. We are not sure of the cost of this repair but it will be a lot cheaper than $14,000 and $30,000 after the killer bolt destroys your engine.

Or you can follow the hype surrounding the Banks YouTube content and get the Banks Monster-Ram intake elbow. This is supposed to replace the grid heater and the offending bolt making your engine run better and be safer.

You will find different suggestions as you peruse the internet for websites discussing this issue.

6.7 Cummins Grid Heater Bolt Recall


Other than the recall we have already mentioned above, there does not seem to be a recall for the grid heater bolt. Do not expect to find or hear about one either.

The reason this is said is because the bolt melting and falling into the manifold is extremely rare. The after-market hucksters, someone else’s term, use this rare occurrence to scare people into buying their products.

One of these after-marketer sellers says that he has seen this failure in 25% of his vehicles but does not say how many vehicles he owns. 25% is just 1 in 4 and he may just be unlucky as the failure rate may be as low as 0.04%

You have to watch what those YouTube sellers say as they may play fast and loose with the facts. One website has stated that this is not a common problem and it only happens rarely. Unfortunately, you may be one of the unlucky owners.

The best thing to do is to do the jiggle test described above. Do this on a regular basis as this is not going to be a problem that happens a day, week, or month after you buy your vehicle. It takes a while for the wires and bolt to melt.

If you keep your eye on it and do the test regularly, then you can catch the problem before it destroys your engine. Here is the recall information you need to know:

How to contact the manufacturer: Owners of affected vehicles can contact Ram at 800-853-1403.

NHTSA campaign number: 21V798. Ram’s own number for this recall is Y76.

Talk to the company about the killer bolt issue.

6.7 Cummins Grid Heater Replacement

There is one solution and it is called the 2007.5-2022 6.7 Cummins Intake Air Heater Relocation Kit but you may not be interested as it consists of a metal ring and a new bolt for $299.

There may be a few other parts included but it is to be paired with an after-market grid heater plate. Of course, you can listen to the Banks spokesman and buy their Banks Monster-Ram intake elbow.

However, according to some 6.7 Cummins owners, you may have to buy other parts as well to fit this device onto your engine. One owner did that and claimed he lost 3 mpg but got better acceleration after 70 mph.

Then you can continue to explore the after-market parts industry and replace the stock manifold and grid heater with a manifold that uses a coil heater. We are not sure which companies produce this part.

A little research should help you find the right part for your truck situation and at a shop near you. It may fit your budget as well.

6.7 Cummins Grid Heater Cleaning


You can clean this device and it will take some elbow grease to get it done. The recommended tools were a toothbrush and electrical contact cleaner. Other owners suggested that you use a vacuum cleaner and hope that no big chunks fall into the manifold.

Most of the owners discussing this topic simply stated that they deleted the grid heater and had no problems with starting their engine. They did the delete at different times but all reported the same results.

There is a 24-step process to do the delete properly and you can read those steps at this link

. Whether it is legal or acceptable to delete this part is another story for another day.

One thing you should know about is that if you take this step, you may get a check engine light illuminating every time you start your engine. That light has to be bypassed. Or you simply do not wait to start your engine. Just turn the key and go.

Talk to a qualified mechanic about both of these options. It may be best to not delete the grid heater and simply clean it from time to time.

How To Avoid Grid Heater Problems in Your Ram

The first step would be to do regular maintenance on your engine. Watch your solenoid and wires to make sure they are not overheating and melting. If you see signs of melting, replace the wires first and that may spare your bolt.

Another step would be to go to the after-market outlets and find the best alternative that will replace your grid heater. There are different issues that arise due to the high current involved and replacing the grid heater may be your best option.

Some people simply delete it and that also solves their problems. There are different shops that will do a tune on your engine and they can solve some of the problems with their work.

You do have options including replacing the manifold for an after-market model. This solves about every problem you would have but keep in mind, the killer bolt issue is rare and may never happen to you.

Some Additional Words

Modern technology may have made emission and mpg improvements in diesel engines, but it has also created more problems for owners to deal with. This is just one of the many problems you may encounter that never existed in early diesel engine models.

Going to the after-market or deleting your grid heater may not be worth it since the killer bolt issue is so rare. Replacing wires and a solenoid may be the better option to take.

Don’t forget to check the recall notice to see if you are on that list.

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