Replacing Your Spacer Plate: When Should It be Done?

CATERPILLAR 3406E/C15 SPACER PLATE, NEW | Highway & Heavy Parts

Installing a cylinder head, whether on its own or as part of an engine overhaul, is a big job--and expensive. It's not unusual for diesel owners to want to find ways to save money where they can on the repair. But is your spacer plate a good place to do that?


What Does a Spacer Plate Do?

In older engines, spacer plates weren't really used. Instead, counterbore engines were popular to help reduce pressure and stress on the liner flange. In these, a ledge is machined into the block for the liner to sit in. This wasn't always as successful, though, especially as load demands on diesel engines increased. Cracks would still occur on the head, leading to leaks and other engine problems. So spacer plates and spacer plate gaskets were developed.

In a spacer plate engine, the spacer plate sits on top of a spacer plate gasket on the block. The head gasket then goes between the spacer plate and the cylinder head. It's designed to reduce stress on the liner flange while maintaining the seal of the head gasket. By reducing the stress in this way, the spacer plate helps to prevent cracks and prolong the life of your cylinder head.

Replacing Your Cylinder Head

Many factors can force you to replace your cylinder head. Most commonly, though, cracks from overheating are the culprit. Rapid heating in the engine forces the head to expand and then shrink back down quickly as the engine cools. This motion eventually leads to cracking. If cracks occur in your cylinder head, you'll almost definitely need to replace it.

You might notice some of the following signs if your cylinder head needs to be replaced:

  • Overheating
  • Poor Fuel Economy
  • Excessive Oil Consumption
  • White Smoke

These symptoms don't always indicate a cylinder head problems, it's one place to start investigating, especially because a cylinder head problem can lead to so many other failures within your engine. You might experience oil contamination, damage to your engine block, or cylinder damage. Not only would you have to replace your cylinder head, but you'd have to address these other costly repairs. So it's important not to rule out cylinder head problems right away. For more in depth information on signs of an issue with your cylinder head, take a look at our earlier blog.


So, Do I Need to Replace My Spacer Plate?

The short answer is that in most cases, yes, you want to replace your spacer plate. Odds are, if you're experiencing issues with your cylinder head or head gasket, your spacer plate has been affected as well. The most important thing to think look for as you decide whether or not to replace your spacer plate is the amount of visible damage. Do not reuse a plate with cracks or wear, as this will not maintain the seal of the head gasket properly.

If the spacer plate has only slight indents on it, you might be safe to reuse it, but in the long run, it still might be best to replace it. This way, you know all your parts should be functioning at their best. You spent all that time and money taking out your cylinder head or doing an overhaul, is this really the place you want to cut corners? You can save yourself time and headaches later on by addressing the problem now.


So while it might just seem like one more thing to replace, in the end you'll probably be glad you didn't ignore the spacer plate when you removed your cylinder head.

If you're wondering about spacer plates or cylinder heads, it might be time to talk to some experts. Call our certified techs at 844-215-3406, or request a quote online. We can help you with this or any of your other diesel part needs!