Elusive noise
I bought a 2005 VW Golf 2.0 FSI GT (not GTI) with 45,000 on the clock, which appears genuine. It is now at 57,400 miles. I'm aware that the FSI engines are noisy – particularly at idle – due to direct injection and a highpressure fuel pump, etc. However, I am concerned about a strange noise when either pulling away or accelerating and, to a lesser extent, when revving the engine in neutral. I can only describe it as a metallic rattle or resonance. Initially, I thought it might be a loose heat shield or exhaust part. I have had two different garages check for this – or anything loose underneath – and they haven’t found anything.
The noise tends to get worse after some miles and is very noticeable in a covered area, for example when parking in a multi-storey car park. A mechanic friend thinks it might be the dual mass flywheel (despite not being a diesel, it is fitted with one), however I can’t hear it rattling at idle, which seems to be the typical symptom of a failing DMF. Another independent VW garage thought “it might be coming from the engine", but weren’t very interested in trying to pin the noise down. I’m reluctant to spend £800+ getting the DMF replaced unless it’s definitely that. Do you have any ideas? Gavin Barnett
The FSI engine can sound quite noisy for a petrol engine. The dual mass flywheel may be the cause, although without actually hearing it, I can only offer a general opinion. As you say, the DMF often becomes very noisy on tickover, although this is not always the case. You say the noise appears to a lesser extent when the engine is revved in neutral, so it may be worth trying this with the clutch depressed to see if it makes a difference. By applying pressure on the clutch, you would also apply pressure to the outer part of the DMF. If this does make a difference to the noise, it supports the theory that the DMF is failing.
Another option for the noise is pinking. The FSI engine likes highgrade fuel, so it may be worth using a premium-grade fuel for the next couple of fills to see if it alters the noise at all. This is, of course, assuming you are not already using premium fuel.
Another option for the source of the noise is the cam chain at the back of the cylinderhead joining the two camshafts via the adjuster mechanism. There have been reports of the cam sprocket and chain wearing prematurely. As this is high in the engine, it should be easily detected by listening from under the bonnet.