Holden Commodore Problems

YOUR problem is a common one with the VS Commodore. Geoff Clay of CPA Automatic Transmissions says your problem was most likely caused by wear in the auto trans valve body, which results in a loss of oil pressure and increased slippage in the torque converter, which leads to your problem when under the load of towing. It would have happened whether you were in third or Drive. His recommendation is to tow in Drive as you were doing. The problem is a result of Holden changing from a cast-iron valve body to a die-cast one in the VS models.

YOUR poptop would probably weigh about 1500kg when loaded, so that's the weight you need to consider when buying a vehicle. In my view it comes down to where you want to go when travelling, and what you want to do with the vehicle for the rest of the year. If you stick predominantly to the blacktop on your travels, then a regular Commodore or Falcon is probably the best way to go. Both will easily tow your poptop, are comfortable and will give you reasonable fuel consumption. An X-Trail will tow up to 2000kg if the trailer has brakes, so that will also handle your poptop. A recent experience with a 3.0-litre Subaru Outback, rated to tow 1800kg, showed that when it was towing a 1200kg camper trailer the fuel consumption rose about 30 per cent, and rose even more when towing a camper weighing close to its rated tow capacity. That said, the Outback would be a great compromise for round-town use and towing capacity.

IT SEEMS the most likely source of the leak is from the rear quarter windows. The best fix is to remove the windows and reseal.

YOUR car was developed to run on leaded fuel, so you should use premium unleaded with an additive such as Valvemaster or Flashlube to protect against valve recession. I recommend PULP because your engine has a relatively high compression ratio and will probably need the 95 RON of PULP.

THERE'S no need to warm up your car before driving off. The presence of a cream/brown sludge in the oil suggests there's water present, and the rough shifts may mean there's some water in the transmission oil. Check the transmission oil, it should be red and nice and clear. If it's not, it would be wise to have an auto trans expert look at it. Your problem could be in the radiator, which incorporates an oil cooler for the auto transmission. A failure there could result in water getting into the fluid and affecting the function of the transmission.

YOU don't say whether your daughter was injured. If she wasn't, the car's body and the seat belts did their job and there was no need for the airbags to deploy. Seat belts are the first line of protection and the airbags are deployed only in a severe crash. Your daughter was travelling at the local speed limit before the crash. I'll assume that's 50km/h. She probably braked immediately before hitting the stationary 4WD, so the speed of impact was less than, say, 40km/h. The energy involved should easily have been absorbed by the car's body and the seat belts. Had the airbags deployed, the damage to the car from the airbags inflating would have been more extensive.

THE 253 was released in 1968 at the same time as the larger 308-cubic-inch Holden V8. Both were designed by engineers at Holden's Fishermans Bend plant. They had several innovations, including advanced use of thin-wall casting for cast-iron components; and extensive use of aluminium castings for components such as the water pump and inlet manifold. This saved weight and helped make it the lightest V8 in production at the time. The 253 was the economy V8 and was intended to compete with the 250-cubic-inch six-cylinder engine in the Falcon. Apart from its smaller capacity, achieved by a smaller bore, it had a two-barrel carburettor instead of the four-barrel carburettor that was fitted to the 308, the performance version of the V8. When the V8 was updated in the 1980 VC Commodore, the 253, then known as the 4.2, was fitted with a four-barrel carburettor among a raft of other changes. It was a sweet-running engine. I have no experience of the Fuelstar inline additive, so I can't offer any advice.

UNDERSTANDABLY the fuel consumption our readers reported varies. It depends on the type of driving they do and how well they maintain things such as tyre pressures. The average fuel consumption was 11.6 litres/100km, the best 10.3 litres/100km and the worst 13.9 litres/100km. Tan's consumption falls within the range, though at the upper end of the figures reported.

LEAKING inlet manifolds were a constant problem with the post-exhaust emission V8 engines, but the manifold on your car was a new and much-improved one as part of the XT5 engine package. Though it's worth checking, it would normally result in a rough idle and possible oil leakage along the faces that mate to the heads. If your engine is running smoothly with no sign of roughness I'd look inside the carburettor and check the float height is correctly set. If your problem is cold-starting, adjust the choke two notches richer. That might be enough to fix it.