The CKRA 2.0L TDI engine found in the 2012-2014 NMS Passat has earned a reputation for decent fuel economy and long-distance reliability. But for some unlucky owners, the engine is infamous for something much more alarming: fuel injectors launching out of the cylinder head like miniature missiles.
This image was (obviously) enhanced for dramatic effect.
To understand why the injectors are shooting out of the engine, we need to look at how they are secured into the cylinder head:
The four injectors on a CKRA are secured with two clamps, each held down by a single bolt. Since two injectors share the same clamp, they are normally ejected from the head in pairs.
The bolt used to hold down the injectors is what is commonly referred to as a “TTY” bolt. TTY or Torque-To-Yield bolts are designed to be tightened beyond the bolt’s elastic limit, causing permanent stretching resulting in consistent clamping force. These are different from conventional bolts, which are tightened within their elastic limit. Conventional bolts can be used, but TTY bolts can NOT be reused as they have been stretched and weakened. The CKRA injector cover plate bolts are very thin to begin with, and once they have been torqued down, reusing them or overtorqueing them can cause them to snap.
Compare this photo to the threads in the next photo:
When this bolt snaps and the clamp releases, there is nothing holding the pair of injectors inside the head. The pressure of the fuel system will send the injectors straight up into the hood of the vehicle and can cause a visible dent on the hood.
Yes, this actually happened.
It is always important to replace these bolts, as well as the seals, any time the injectors are removed from the vehicle. We offer a fuel injector install kit that includes all the bolts and seals, so you will have no issues reinstalling the injectors.
