VVT TROUBLE
Longdrop Scheepers did not get his nickname because he’s tall. No, he was called Longdrop after his son Hannes accidentally bumped a tractor against the outside toilet while his dad was inside. Luckily, the hole was only three metres deep. It took Hannes just 10 minutes to get him out by means of a long rope at the end of the errant tractor. Our community will take far longer to forget the incident.
Longdrop’s pride and joy is his 2005 Volkswagen Golf 5 GTI. It has served him well through the years, but at 145 000 km, it’s sounding like an old diesel. The engine runs rough and makes a sound that Japie, with the insensitivity of youth, calls a death rattle.
Syd took the car under his wing and it didn’t take him long to locate the source of the rattling sound. It came from the variable valve-timing (VVT) unit situated on the end of the intake camshaft. It is attached to the timing-chain sprocket that is at the flywheel-side of the engine.
Japie came strolling over and asked Syd: “Why is the timing chain not at the other side of the engine, where it will be easier to service, like on most other engines?”
Syd’s answer was not the one Japie expected: “Young man, you’re not reading enough. Go and find out, and tell us tomorrow while we’re all together during lunch.”
The next day, Japie turned up with the information that many modern engines have the valve-timing chain on the flywheel-end of the engine where the camshaft’s motion suffers fewer disturbances from torsional vibration than it would experience at the other end. “What is torsional vibration?” asked Hennie. “According to CAR, it’s a vibration caused by the regular beats of the power strokes,” said Japie. “The result is that the crankshaft shakes almost like the way a wet dog does when it wants to get rid of the water.”
We were all impressed but Japie went further. “I saw on the Internet that some Golf 5 GTI models suffer from unusual wear on the VVT units, and that Volkswagen has released an upgrade kit consisting of a VVT unit, sprockets and timing chain that will solve the problem.”
“Wow,” was all I could say. We were all proud of our disciple and heaped praise on him.
Further investigation showed that Japie was correct. We ordered the kit, which cost about R9 000, and Syd fitted it in an afternoon. When he started the engine, we all knew the diagnosis was correct.
SHAFTED
Charlie Vosloo is a bit of a Ford fanatic, but I won’t hold that against him. After all, Ford did not ask for a bailout from American taxpayers like the other two big companies.
Some months ago, Charlie bought a 1998 Australian Falcon in good condition and revelled in the power and torque delivery of the 4,0-litre six-cylinder engine. In a weak moment, he had an expensive aftermarket exhaust system fitted that promised an extra 20 kW.
The thrill lasted until the day that he showed off by doing some burn-outs and figures of eight on an empty parking lot. Initially, the car responded beautifully, but eventually the driveshaft twisted off.
Japie towed in the car, removed what remained of the shaft and then noticed it was nearly new. We all sat down for a pow-wow to decide why the shaft broke, because there would be no point in simply replacing it without knowing more about the incident.
At first, we thought that Charlie was simply too rough with the car, but Hennie disagreed. He had consulted an old CAR issue and found that the engine developed 157 kW. The extra 20 kW was only a 13 per cent change, and this should not be enough to twist the new shaft on a model that was designed for Australian conditions.
Syd pointed out that it did not look like a Ford part and did not carry a part number. This made us all suspicious and I suggested that it was a cheap import. We concluded that more information was needed.
I phoned Charlie and I’m sure, had I seen him, he would have been red-faced. He admitted that he didn’t tell us about the new shaft because he thought we might disapprove if we knew the truth, which was that the tuning shop fitted a self-constructed, smaller-diameter driveshaft because the Ford part interfered with the large-diameter exhaust system. They assured him it was made from better-quality steel than the original shaft.
“They may be right, but I doubt it,” was my response. I then asked Charlie’s permission to make the modifications needed to fit a genuine Ford driveshaft, and suggested that he should leave the cowboy tactics to rich youngsters.