Tracking Down Alarming Noise, Two months of agony Options

[Osnabruck914]

Two months ago, out of the blue, my '74 2.0 suddenly started making an alarming clunk and rattle on startup and acceleration. After complete warmup the sound diminished but was always still there but never affected performance.

I started my investigation by getting under and over the car, tightening every possible screw and bolt that could be loose- transmission mounts, engine bar mounts, engine tin, starter bolts, etc., etc. No luck. I was starting to have nightmares thinking it was something deeper inside the engine. Took the car twice to my local 914 guy, who spent a lot of time looking for the source of the noise. He was baffled, but assured me he thought it was nothing serious and that I would find it eventually and he was right.

I finally decided to remove every heater component on the driver side to start ruling things out- that did nothing. but when I removed the passenger side heater components presto- no noise! When I put it all back together, the noise came back, but at least I was sure it was one of those passenger side heater pieces.

Results - Found the passenger side warm-air elbow (see pics) that connects the heat exchanger to the heater valve box was bouncing and rubbing on the engine bar- that was the annoying and alarming noise I was hearing. After properly tightening and positioning that elbow all is normal and I can sleep soundly again. As a bonus, the car is extra smooth and quiet now, as everything possibly loose and rattley has been tightened (IMG:style_emoticons/default/smile.gif)

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