Chrysler has recalled the timing chain assemblies in just over 50,000 5.7-liter Hemi-equipped Dodge Challengers, Dodge Chargers, and Chrysler 300C models built between 2009 and 2012. (SRT vehicles are not named in the recall, at least not yet.) All have the MDS feature with automatic transmission, and can encounter sudden, catastrophic engine damage when in fuel-saving mode. We know this first-hand as our very own bone-stock 2011 Dodge Challenger R/T recently encountered engine failure on the highway at speed. (See pics.)

A quick internet search reveals that the Hemi timing chain defect has plagued the affected cars for several years, and message boards had been discussing the failure for some time prior to the official recall (often running against strong denials by Dodge and Chrysler techs as well as Chrysler officials). Of the threads we discovered, the most significant one with over 500 pages can be found at www.ChallengerTalk.com.

Owners of affected cars at ChallengerTalk.com report that the timing chain on 5.7-liter Hemi cars fails suddenly and without warning, in most cases at highway speed and in four-cylinder fuel-saving mode. (Six-speed manual cars are not affected because they are not equipped with MDS, which is Chrysler’s patented cylinder deactivation technology.)

Now that Chrysler has taken ownership of the timing chain defect, the blaming of customers has finally subsided. Dealers are handling the recall by replacing specific engine equipment under Customer Satisfaction Notification P01. The affected parts include the timing chain, timing chain guide, timing chain tensioner and spring, pick-up tube and o-ring, heater tube o-rings, and timing cover gasket. A known fault in the oil-control valve assembly for which an updated part exists (earlier versions have a filter screen that comes loose) are not currently approved for upgrade/update as part of the recall.

Now that Chrysler has taken ownership of the timing chain defect, the blaming of customers has finally subsided.

Not all is going smoothly with the recall of the timing chain defect. If your timing chain fails before you get your Hemi to the service department for the recall work, the repair may be drawn out over a much longer period of time due to an obscure provision in the repair procedure that hopes to ignore certain laws of physics. (It boils down to dealers wanting to double-bill the factory for one operation and being able to get away with it, while the factory hedges its bet that no damage actually took place.)

According to the service department where we took our Hemi Challenger (Moss Dodge in Moreno Valley, CA), Chrysler policy on failed engines is this: Technicians may perform only the recall service work to the timing chain—irrespective of whether or not the chain has broken. They are required to reassemble the car, attempt to start it, and then once engine damage is subsequently confirmed can the engine be torn down (again) for the far more significant mechanical damage to be repaired.

In our case, all 16 valves were hammered, with leakdown between 20 and 80 percent on all cylinders. New cylinder heads, valves, and springs are being installed with a total down time of at least two weeks. As the 5.7-liter Hemi is an “interference” engine by design, it’s inevitable that piston-to-valve damage will occur if any attempt is made to start the vehicle after the timing chain breaks. And here’s the irony: The service procedure is to crank the engine as the first step in the diagnostic process—an act that locks in the engine damage before the first wrench is turned.

There are some interesting consequences to the recall. First, it appears that members on the ChallengerTalk.com board who have made engine modifications and have also experienced failure from the timing chain defect are not being covered under the warranty or the recall, in spite of the fact that the MDS system—not aftermarket parts—are the culprit. The lesson here: do not modify your automatic-equipped 2009-’12 Hemi under any circumstances while under the 100,000-mile powertrain warranty.

The second interesting thing is that disabling the MDS fuel-saver mode with an aftermarket tune appears to prevent the timing chain failure from happening. That’s also ironic, because saving the engine from damage in effect voids the warranty. In fact, anything you do on your own to fix it while waiting for the recall notice will void the warranty.

If your car falls under the recall and you haven’t had the warranty work done yet, but you still need to drive your car, the consensus at ChallengerTalk.com is that it’s best to drive the car in manual auto-stick mode, which forces the computer out of MDS fuel-saver operation and into V-8 mode. Our dealership says Hemi cars with snapped timing chains and broken valves are coming in faster than running cars with recall notices, which should give you an idea for the severity of the problem. No word yet if Chrysler is paying for damaged cars that subsequently get in an accident as a result of engine failure, so our advice is to park it until you get a recall notice.

To find out if your Chrysler vehicle is part of this recall or any other, click here, then click on “Your Vehicle," select “Recall Information” from the pull-down menu, then enter your VIN number.