Quick Replies

Q: I HAVE a 2006 Golf 5 1.9 TDI with 130000km on the clock. I was driving on a gravel road during heavy rains when the engine stopped and would not restart again.

I took the car to a VW dealer where a mechanic told me the engine had seized. He introduced me to a former colleague who has his own workshop, as "VW are not overhauling engines". The guy fixed the car, but after driving about 80km the engine cut out. I took the car back and again it was "fixed", but the engine still cut out.

The mechanic talks of a cylinder head problem and damaged valves, but it seems he can't fix it properly. What might be the problem? - Peter

A: Peter, it is not clear what exactly happened, but the worst-case scenario is that water seeped into the combustion chambers. If that happens, a condition called hydrolock occurs where a piston will hit a wall of water as it comes up on the compression stroke and, because water is incompressible, something has to give - usually a conrod that bends, valvegear that gets damaged, or the cylinder head gets cracked.

If this was the catastrophe that hit you, I would imagine the private mechanic's "fix" amounted to a comprehensive engine overhaul. Half-measures are useless - you have to strip it completely and examine everything. Not only do you have to replace all components that were damaged, however slightly, you also have to dry out, flush out or suck out the water from wherever it sneaked in, including the fuel tank and crankcase.

It seems the mechanic was not thorough enough. I suggest you seek the opinion of someone with experience of water damage on VW diesel engines.

Q: SOMETHING that has been bugging me in Motor Mania is an Audi advert for "genuine shock absorbers". It states: "They support your entire car". It may apply to a small percentage of cars, but the majority of vehicles are supported by springs, not shocks. I thought VWSA would know better. - Tommy

A: You are correct, Tommy. As VW/Audi would know, you can remove all the shock absorbers on a car and it will stand at the same height as before. Cars with adjustable ride-height usually have air springs or hydropneumatic suspension, so even there the support comes from the springs.

The ad is adspeak where phrases are used for emotional effect, rather than to convey factually correct information. Interestingly, the illustration with the ad highlights the spring by showing it in red. If the copy writers had stuck to "shock absorbers provide a smoother ride", no one would have a quibble with it.