At this point, just about everyone knows about the big coolant-burning problem with the Ford Focus RS. As it turns out, it’s not a problem with the engine at all, but really a problem with the head gasket used to seal the mating surface between the cylinder head and the engine block. One Focus RS owner had been digging into the problem for quite some time, reporting this problem to a very long thread on FocusRS.org forums. Upon getting his engine apart found that his head gasket was, indeed, blown. But, it’s not the fault of the gasket itself, as the gasket wasn’t designed for the Focus RS – it was designed for the Eco Boost Mustang, as evidenced by the part number cast into the metal portion of the gasket itself.

Keep reading to learn more about this breaking development

Your Focus RS has a bad Head Gasket? Nope.. It's the Wrong Gasket

The images you see in the tweet above were originally posted on FocusRS.org and later investigated by Bozi Tatarevic. Upon noticing that the part number was likely that of the gasket for the 2.3-liter found in the EcoBoost Mustang. After reaching out to a parts supplier, who has requested to remain anonymous, it was actually confirmed that that part number was marked as originally being built for the EcoBoost:

And, this is where things get interesting because it’s commonly believed that the EcoBoost Mustang and the Focus RS have the same engine crammed under the hood. That, however, couldn’t be further from the truth. There are lots of differences, including different materials used in the composition of the block and cylinder heads. Despite the fact that the engines are the same displacement, and even look somewhat similar at some angles, they are actually unique to one another, which means the coolant passages between the block and cylinder head of the RS are different than those in the engine of the EcoBoost. As such, the incorrect gasket in the Focus RS causes a coolant blockage. This ends up resulting in a hotspot within that part of the engine or cylinder head. The coolant eventually boils and is forcefully pushed out between the mating surface – blowing the head gasket.

As for how this happened remains unclear. It could have been a simple mistake in the rush to get production going. After all, there was a problem with Ford hitting its delivery targets and a ton of drama around it; mistakes happen when you rush. The problem is limited to early models and maybe 3 percent of the entire production run, so it only affects a handful of models in the grand scheme of things. The chances are that someone grabbed the wrong crate in a hurry and, since the engines are so similar, nobody noticed the problem.

Ford, so far, has been sending customers that have fallen victim to this problem back to the dealer for warranty repair, but now you really have to ask: Have the hot spots created by the lack of coolant flow pose any risk to the engine down the road? Is there a higher chance of engine or component failure? An official word from Ford or an official fix has yet to be announced, but with all of this new information coming to light, you can bet the blue oval with start investigating. Ford will likely continue to replace the head gaskets, only under recall instead of warranty, but with any luck, customers will find themselves getting all new engines – it would be an easy way to ensure there won’t be any other problems as a result of this seemingly minor but catastrophic production mistake.

What do you make of all of this? Are you one of Ford’s customers that are dealing with this problem? If so, leave us a comment below telling us what you expect the official fix to be.

References

Ford Focus RS

Read our full review on the 2017 Ford Focus RS.

Read more Ford news.