For most motorists, a cracked head is the end of the road for their vehicle. However, when the engine powers commercial transport and hauls up to the million-mile mark, it’s worth a lot more to get it fixed.
If your Cummins ISX engine suffers the fate of a blown head gasket due to high-mileage wear and tear or as the fallout of another system failure, the repair is expected to be costly.
The average cost to replace a Cummins ISX head gasket is $5,700. This includes the cost of parts and an average of 30 hours in labor.
It’s a big price tag, but compared to the cost of dropping a new engine at upwards of $14K, it is barely more than one-third of the cost. This price tag includes an average of $4,100 in labor and $1,600 in parts.
- Cummins ISX Head Gasket Replacement Cost
- What Causes a Head Gasket to Fail?
- Symptoms of a Blown Head Gasket
- What Factors Affect the Cost of a Head Gasket Replacement
- Is it Worth Getting a Cummins Certified Repair?
- Related Guides
- The Bottom Line
Cummins ISX Head Gasket Replacement Cost
A head gasket is a vitally important seal that closes off the combustion chamber of the engine.
This gasket allows coolant and oil to circulate through the engine. It also allows the combustion chamber to build up enough pressure to function. As you might imagine, when a head gasket blows, the damage can be catastrophic.
What Causes a Head Gasket to Fail?
The most direct cause of a blown head gasket is high engine temperatures. What causes engine temperatures to rise is another matter that will need to be diagnosed and addressed.
Most often, the problem begins with a coolant leak. As coolant levels drop, engine temperatures rise.
Modern head gaskets have higher thermal ratings and are more resilient, but every component has its limits.
When a head gasket blows, timely intervention is critical to preventing irreparable damage that locks the engine up and tripling the price tag to get the truck back on the road.
Symptoms of a Blown Head Gasket
As the head gasket begins to fail, small leaks of coolant begin mixing with the oil. This significantly reduces the coolant’s ability to do its job and causes the engine to overheat.
The most obvious signs of a problem with the head gasket include:
- High Engine Temperatures
- White, Blue, or Gray Smoke
- Loss of Power
- Discolored Oil
As already explained, an overheating engine is caused by a loss of coolant or mixed fluids, reducing the efficacy of the coolant to do its job.
In addition to running the temperature gauge higher than normal, drivers might also see white, blue, or grey smoke that indicates a mixture of fluids.
White smoke is produced by leaking coolant that enters the combustion chamber and is turned into steam. Grey smoke is produced by oil that enters the combustion chambers, emitting a thick carbon smoke as it burns.
Oil smoke can also sometimes look like it has a bluish tint. Another sign of mixing engine fluids can usually be found in the oil reservoir.
Engine oil should range from a translucent golden color to dark brown or even black color, depending on how fresh the oil is. On either end of the spectrum, the color is pure, with lighter tones appearing translucent.
As the colors become darker, the opacity becomes thicker. When oil mixes with other fluids like coolant, it becomes milky in appearance.
All of these signs are symptoms of a bigger problem. When the head gasket blows, the seal to the combustion chamber is compromised, making it difficult to build up power to operate the engine. This results in a lack of acceleration power.
A blown head gasket gives plenty of warning signs. At the first sign of trouble, it is time to get the engine to a shop right away in order to minimize the damage to your engine.
What Factors Affect the Cost of a Head Gasket Replacement
As with all engine repairs, there is a range of options, from budget-friendly options to full-service rebuilds. This is why there is such a range of prices from one head gasket repair to another.
A mom-and-pop repair shop in a rural area using aftermarket parts is likely to offer a more reasonable price tag than a big city dealership offering OEM parts and a full rebuild with dozens of additional replacement parts that will help the longevity of your engine but are likely unnecessary.
OEM Parts Vs. Aftermarket Parts
OEM parts stand for an original equipment manufacturer. These parts are made by the same manufacturer as the original engine and provide a quality level that consumers can trust.
OEM parts also tend to come with warranties and premium price tags. But for many consumers, the higher price is worth the peace of mind.
Aftermarket parts are made by a variety of manufacturers, and while they are designed to work with a certain model, there are no guarantees made by the engine manufacturer regarding compatibility.
Most often, aftermarket parts from reputable brands perform just as well as OEM parts. However, with a more saturated market and often slimmer warranties, they come at significantly lower prices.
The main problem with aftermarket parts is comparing apples to oranges. For every reputable manufacturer that provides a quality product, there is another one trying to make a quick buck.
Sometimes sorting through all of the options can be overwhelming, and many drivers prefer to pay for the name on OEM parts.
Certified Dealer or Qualified Mechanic
Who installs the head gasket and how much they bill for labor is a significant part of the overall cost of replacing the head gasket.
The whole job can take anywhere from 30-40 labor hours from start to finish, so those costs are going to be a significant portion of the final price.
Labor rates for truck repairs vary significantly, with averages falling as low as $47 per hour and reaching as high as $215 per hour. A lot of factors go into determining how much a shop can charge for labor.
Small shops in rural areas will have lower prices than big dealers in larger cities. Similarly, a new business will have lower rates than a well-established business with a solid customer base. And reputation counts too.
A Cummins-certified shop will charge more than an otherwise qualified mechanic who is not part of their certified network.
The extent of the Damage
If caught early, the shop may be able to salvage your engine with just the replacement of the head gasket. That is a best-case scenario.
However, every mile that your engine drives with a compromised engine, the damage is being done to the entire system. If the repair involves multiple parts of the engine, up to and including a complete engine rebuild may be necessary.
And the price tag goes up with each repair. In certain cases, it is recommended to polish the head before putting the new gasket in order to avoid leaks.
Is it Worth Getting a Cummins Certified Repair?
With parts and labor cost significantly more under the Cummins name, many drivers may be weighing their options. But what do you really get when you buy name-brand OEM parts and services?
Cummins costs more because they have invested some serious time into testing various components for compatibility and longevity. Using non-genuine parts may be a cost-effective option that generally works out in your favor.
But it can also be a costly and avoidable mistake. And when you rely on your engine to provide your livelihood, those are risks you may not be able to afford to take.
And the same goes for labor. When technicians are trained in factory-authorized training centers, they carry the same quality of service into every repair job.
And the service and parts are backed by outstanding warranties with exceptional coverage.
The answer is a strong yes. If you have access to use Cummins certified repairs and parts, always choose the best to keep your truck in top running shape.
There are some frugal-minded drivers out there who would argue this point until they are blue in the face. And the truth is that it is possible to get something that works just as well for a fraction of the price.
There are quality mechanics that aren’t certified by Cummins. And there are plenty of drivers getting good outcomes outside of the Cummins brand name.
But the risk lies in details. There is a lot of uncertainty between one mechanic and another and between one parts manufacturer and another.
If you make the right choices, your outcomes will be good, and if you don’t make the right choices, you could end up saving a little right now and spending a lot down the road.
The Bottom Line
Replacing a head gasket is a labor-intensive endeavor. Your mechanic will spend at least a week working on it.
And with labor costs ranging from $47-$215 per hour, the labor alone will cost $1,645-$7,525. For OEM Cummins parts, plan to spend about $2,000, making the total cost to repair between $4,000-$9,000.
While this is one of the more costly repairs, it is still significantly less than the $14K price of dropping a new engine.