Volkswagen’s troubles continue, but this time it’s not emissions-related cheating, it’s failing camshaft lobes which can wreak havoc on braking performance.
Volkswagen is recalling 91,867 cars including the 2015-2016 Jetta, the 2015-2016 Beetle, 2015-2016 Golf SportWagen, 2015-2016 Volkswagen Passat and 2015-2016 Golf
and Golf GTI (see update below). It’s all over troubles with the new EA888 engine.
That engine is a good one. I just reviewed the 2016 Passat and found that little 1.8-liter Turbo version of the EA888 to be a darned good mill.
But, it turns out, I got lucky, because the EA888’s exhaust camshaft lobes have a tendency to shear off. The exhaust camshaft drives the fuel pump and brake vacuum pump, so once that camshaft is toast, there go your power brakes. And without power brakes, that corner up ahead is gonna get really hairy.
Normally camshafts are machined from bar stock or cast from molten iron, but Volkswagen opted for modular sintered camshafts, whose lobes are pressed on. The friction from interference fit between the lobe’s and the shaft causes the lobe to “become one” with the shaft.
NHTSA says the camshafts are shearing due to “high load” on the cam. Whether that’s the only cause is not yet clear. I’d guess that the failures have something to do with the assembly process and too high of an interference between the shaft and lobe. This could impart high radial stresses on the lobe and weaken it.
Volkswagen, will your woes ever end?
Update: We called VW for more info, and they told us the GTI is actually not part of this recall (they’ve submitted a new form 573 to NHTSA that does not include the GTI). Additionally, VW’s rep says it’s more likely that the lobe is actually spinning around the shaft, rather than shearing, but that hasn’t been confirmed.
Update 2: After another call to VW, it looks like they will issue a stop-sale on 3,500 affected vehicles.
Update 3: NHTSA has updated their Safety Recall Report so that it no longer includes the GTI.