Hi Guys
I have a Spanish registered, LHD, 300tdi 90 from 1996. It lives in Spain. I've only had it a couple of months. The other day I was happily pottering along the local motorway at about 100kph (60MPH) when the temperature gauge went off the scale. Before I could react, the engine made a horrible mechanical noise and died. I coasted to the hard shoulder and waited a while (expecting the worst!). When I tried to restart her, the engine would not turn over. Bugger I thought, seized engine. However, once it had cooled down I discovered the expansion tank was dry and that there was a brown stain down the left side (exhaust side) of the engine. To cut a long story short, by topping up with a lot of water at EVERY petrol station, I managed to get the car the fifteen or so miles home. It turned out, there was no gasket behind the water pump, just a bit of sealant, which had failed.
Anyway, a new P gasket, water pump, thermostat, and some hoses later all is nearly well. She starts on the button with the usual welcoming puff of black smoke then runs with no loss of power or significant smoke. However, there is an annoying tapping sound, which appears to be coming from cylinder 1. When I crack open the pipe the noise stops, then reappears when I tighten the union up again. The same does not happen with the other three cylinders. I have listened for ages with an engineers stethoscope and cannot trace the noise to anywhere else. The noise is there hot or cold but disappears on overrun.
I am concerned that continuing to drive with it like this may be causing damage inside the engine. The valve clearances are spot on, with all valve caps in place. All rocker shaft bolts secure. Any suggestions welcome. Could a faulty injector cause such a noise?
