Diesel Diagnosis: 7 Common Caterpillar C15 Cylinder Head Problems

Caterpillar has been a renowned manufacturer of heavy-duty diesel engines since its inception nearly 100 years ago. The C15 has been an integral part of helping keep the Caterpillar name at the top of everyone's list. Have a look at our Cat C15 engine spotlight here!

Here at Highway & Heavy Parts, we pride ourselves on providing you with as much information as possible when it comes to diesel engines like the Cat C15. But like with anything, this engine comes with its downsides. Cylinder head issues are not common, but do happen depending on how the engine was used, maintained, and what it was used in. We have a variety of Caterpillar cylinder parts that cover the most common models including the C15.

We have created this article to help you understand the reasons why cylinder head issues happen on a Cat C15 diesel engine, what are the common failure symptoms, and what can be done to prevent them. Of course, other problems could affect the cylinder head, but these are just the most common. We also have created a short video outlining the C15 diesel engine cylinder head issues. Check it out below!  

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7 Common Caterpillar C15 Cylinder Head Issues

As previously mentioned, the Cat C15 diesel engine is very robust. Unfortunately, cylinder head issues on this legendary engine have happened in the past. These include, but are not limited to: 

1. Coolant Loss 

No matter what engine you have, a loss of coolant is never a good sign. The cooling system on a vehicle is sealed, meaning that any drop in coolant levels should be cause for concern. A defective cylinder head could very well be the cause of your coolant loss. 

2. Compression In The Cooling System 

Added pressure in the cooling system could be caused by several factors including a damaged cylinder head. Alternatively, it could be caused by a damaged head gasket. An experienced shop such as Highway & Heavy Parts can easily help diagnose the problem. 

3. Fluid In The Exhaust

A cracked, damaged or warped cylinder head could allow fluids such as coolant into the exhaust system. This can be noticed through the excessive amount of white smoke that is associated with burning coolant. In most cases, the smoke is accompanied by a distinct smell. 

4. Compression Leak Or Chirp Under Load

A compression test can be easily performed to determine if there is a head gasket issue or even worse, a cylinder head issue. When an engine is idling, all may seem fine. But put it under load and issues such as a small compression leak or “chirp” may show their ugly head.

5. White Smoke

As previously mentioned, white smoke is never a good sign. It is caused by coolant making its way into the exhaust system. This can be attributed to a failing head gasket or defective cylinder head.

6. Sludge Under The Oil Cap

Oil and water just don’t mix. The same goes for engine coolant and oil in your Cat C15 engine. Finding something similar to chocolate milk under your oil filler cap should be an immediate cause for concern. It could be something as simple as condensation or as serious as a cracked or warped head. In either case, it should be checked out as soon as possible. 

7. Overheating

Possibly one of the most noticeable signs of a damaged or failing cylinder head on your Cat C15 diesel engine is that it overheats. If this happens, pull over immediately to prevent any further damage from occurring. 

Recognizing that your C15 has an issue is one thing, but knowing what to do about it is an entirely different ballgame. Do you think your cylinder head may need to be replaced? Have a look at the article we have about replacing your cylinder head here.

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What Causes C15 Cylinder Head Issues?  

When it comes to cylinder head issues, the most important question to ask yourself is “why”? Understanding what caused the issue in the first place will help prevent it from happening in the future.

As far as overheating goes, there could be several causes for it. A damaged cylinder head will cause a loss of coolant and therefore increase engine temperatures. Abnormally high temperatures mean that cracks or other cylinder head damage are unavoidable.  

Cracks will cause the coolant to enter areas of the engine where it shouldn’t, like the cylinders. This can lead to a variety of issues such as contaminated oil and a buildup of pressure, which will, in turn, create more stress on the cylinder head and cause more problems.

Cylinder head warping is another issue that can be caused by overheating. Over time, the constant extreme heating and cooling cycles of the engine head will cause issues. Constant expansion and contraction will eventually lead to a surface that is not completely flat and “true”, therefore not being able to create a perfect seal between the head gasket and head. 

Want to know more about cylinder head issues and what causes them to crack? We have put together an in-depth guide on what causes cracks and what you can do about it. Read it here.


Final Words

If you didn’t catch the problem in time, it is important to find out what caused it in the first place so that future issues can be avoided. Sometimes just replacing the damaged head will not get rid of the initial issues. Was it a defective thermostat? How about a bad head gasket? Crucial questions such as these need to be answered to prevent further headaches down the road. 

Looking for a new cylinder head, engine rebuild kit, or virtually any other part for your Caterpillar C15 engine? Highway & Heavy Parts has you covered. Our knowledgeable, ASE-certified staff will help get your C15 back up and running in no time. Give us a call at 844-447-1453 or request a quote online today.

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