MotorBiscuit has covered the rise in Bronco engine failures recently, but now owner complaints filed to the National Highway Traffic Safety Administration are on the rise. That has increased scrutiny by the agency, with Ford acknowledging there are issues. Though speculation as to what the problem varies, it appears to be zeroing in on one problem. 

What Bronco engines are involved?

This is occurring mostly with the 2.7-liter V6 EcoBoost engine. Owners and dealers report valvetrain failures, with the valves themselves being at fault. And the failures have occurred in Broncos with literally just a few miles on them, up to several thousand miles of use. As of now, the NHTSA has received over 50 complaints about engine failures. It opened up more extensive investigations in July. 

The sweet spot for failures to happen seems to be around 2,500 miles. Since there is no information from either Ford or the NHTSA as of yet, we have to rely on forums like Bronco6g. Scanning through, one member says engines built between May and October 2021 are the most susceptive to failures. The procedure for engines like the 2.7-liter built at the Lima, Ohio, engine facility, is to test any new batches of valves that come in from suppliers. That was surely done. 

Ok, so we have problems with the valves, but what is the specific problem? Supposedly, the defect is in the metallurgy, where the valves become brittle due to heat in the valve chamber. Usually, something like a stem breaking or the valve dropping into the cylinder will cause catastrophic failure. Even the engine block can be damaged beyond repair. 

Could this be affecting more than just Broncos with the 2.7-liter?

But this is still forum speculation. At least for now. It is unclear if this is isolated to 2.7-liter engines in Broncos, or is a wider issue with other models using the same engine. The good news is that any and all engine failures are covered under the Bronco warranty. But is a recall warranted?

Right now, almost any Bronco with this engine can be subject to valve failures, until Ford tells us otherwise. If your Bronco shuts down, you will naturally have it towed to the nearest dealer. They’ll know if your Bronco is a victim once they run the codes and conduct some simple tests. 

Here’s how to determine your Bronco’s build date

Should you be curious as to when your Bronco was made, that’s easy. The VIN numbers contain three letters. After the last letter, you’ll see a long line of numbers, but the first five give you the build date. So if you see “22110…..,” your Bronco was built on May 10, 2022, where “22” is the year and “110” is the 10th day of May on the Julian calendar. By the way, if that is your build date, you’re probably not affected. 

Only early production Broncos seem to be affected. The NHTSA is not reporting many complaints related to newer production vehicles. And production has really ramped up since then. And with these failures usually happening to early models, we may have already seen the end of problems for those vehicles susceptible to it.