The Mk7 Golf GTI came out almost a decade ago (in Europe) with one of the best 2.0-liter engines around. While it didn’t have substantial power increases over its predecessor, the 3rd-gen EA888 TSI four-cylinder had torque and great fuel efficiency which make the GTI a great daily. Generally, these engines are seen as reliable, but one issue has begun to creep into online forums in the past months: failures of the intake camshaft system.
The Gen 3s came with an entirely new cylinder head, a 16-valve aluminum DOHC redesign that integrates a water-cooled exhaust manifold for efficiency. As with older generations, the camshafts are driven via a timing chain. You have a variable valve timing system on both intake and exhaust cams.
In short, the intake valves let air into the cylinder, and the exhaust valves let the air into the exhaust system. They’re operated by the lobes on the camshaft which spins with the motor. But an all-mechanical system operates the same at all rpm, all the time, which may not be optimal.
Unlike variable valve lift (VVL) which has different lobe profiles on the shaft, VVT just has one set of lobes and uses oil pressure rotate the shaft and make the valves open sooner or later. The computer module decides if it wants to advance or retard the timing and activates a solenoid to move a valve and rotate shift in relation to the sprocket that’s on the chain.
What adjusting the intake valves does
Honda’s VTEC is famous for added performance and cool noises. Volkswagen’s variable valve timing serves a less exciting but still important role, which is to generally reduce emissions.
By closing the intake valve late, some of the air is pushed back into the manifold. You have less air in the cylinder, less fuel is added which lowers the combustion temperatures and you have lower NOx emissions. Meanwhile, closing the valves early is great for low RPM. Essentially, it reduces the losses of the motor by having it push less air around.
2.0 TSI intake camshaft failure: diagnosing the issue
This issue has the potential to cause a lot of money Fortunately, there are ways to diagnose this way before something major happens. Specialist parts store and VW shop Deutsche Auto Parts does a great job of walking you through the process.
First, there’s a sound. Unfortunately, this sound is quite similar to the rattle of any TSI direct-injected engine. But if you unplug the cable connected to the solenoid/magnet on the upper timing cover. If the noise stops, you know what’s going on. DAP goes further by highlighting an error code on OBDeleven, a diagnostics app that seemingly every GTI owner has. The actual value of the intake valve adjustment is moving all over the place as the system is trying to adjust.
Unfortunately, fixing the issue isn’t easy as it means the engine needs to come apart and a new camshaft needs to be installed. Most likely, the seals (they look like rotary engine seals) in the VVT system are failing and oil is moving around the way it’s not supposed to, allowing the system to make that knocking noise. The part isn’t expensive, but there’s a lot of work involved.
Consider doing these things first
The camshaft problem is way more common on the Gen 3 1.8 TSI engines which are known for starving themselves of oil. So make sure your GTI is always topped on oil and use high-quality stuff.
Second, if your dashboard showed a check engine light, it’s worth seeing if the magnet/solenoid module is working because that can fail as well. Owners are saying that the magnet fails due to sludgy oil adhering to the solenoid plunger (again, more common on 1.8 TSI). This is a way cheaper fix. Also, if you unplug the magnet but the timing still wonders, it’s likely that the lock pin has stopped locking the cam system.