Holden Commodore Problems

YOUR mechanic has covered the most common causes of a miss. The next things to check are vacuum leaks and fuel pressure. Start with the vacuum leaks, and look for leaking vacuum hoses or a leaking intake manifold. Next check the fuel pressure, which might show up a faulty fuel pressure regulator.

I WAS the development engineer on the 4.2-litre V8 back then, so I have a soft spot for the engine and I'm happy you have had a good run out of it. The 4.2-litre engine was a sweet-running, smooth little V8 once the four-barrel carburettor was fitted. The easiest and least expensive course, and the one I would recommend, is to rebuild the motor and adapt it to run on unleaded.

IF YOU check your owner's manual you will see Holden recommends using the brake to hold your vehicle on hills. That said, it is unusual to have to use the brakes to stop the car rolling backwards. It's possible the idle speed is on the low side and the torque converter is also low in terms of take-up. If you're not happy with Holden's response, argue your case again. On the face of it I think you have one. You could also consult an auto trans expert to make sure all is well.

YOUR Commodore has a six-cylinder engine bought from Nissan, basically the same that was fitted to the Nissan Skyline here. The engine is a fine unit, but there was an installation problem when it was fitted to the Commodore, and it can give trouble when air pockets develop in the cooling system, causing the engine to overheat. It's important to use the correct coolant if you have to top up the cooling system -- don't use water, and be careful to bleed the cooling system properly if you have to service it for any reason. The auto is generally reliable, but it is expensive if you have to rebuild it. One thing to check is the service history. Older drivers often consider servicing too expensive, especially if they do few kays. Find out if the car has been well serviced, and if it hasn't think about getting it serviced.

THE flat spot sounds like fuel vaporisation. Fuel can vaporise in the fuel rail because of the heat generated while sitting idle, and it can cause a slight misfire when it's time to go. Get the fuel pump checked to see if it's delivering its full flow of fuel. Also check the fuel-pressure regulator to see if it's maintaining the correct fuel pressure.

IT'S UNLIKELY to be coming in through the tail lights. First check the condition of the boot lid seal, the most likely cause. If that's OK look around the boot for any sign the car has been in a crash. It could be that the boot lid is out of alignment and not seating properly on the seal. If all that appears OK, lift the boot mat, remove the spare, and thoroughly check the whole boot area for telltale water stains.

THE Commodore will tow up to 2100kg with the approved tow hitch, but it comes down to the weight of the caravan and what the regulations will allow you to tow. Check with Vicroads for the maximum for the VT.

IT'S great to hear that you are not having any oil consumption issues with your Gen III V8 Commodore. There is no great risk in fitting a chip providing you consult an expert and buy a recognised chip. Give Peter Schweighofer a call at Swift Automotive in Dandenong and he'll be able to advise you on the best gear to use.

IF THE noise is a light rattly one heard only when the engine is cold, then it's more than likely to be the hydraulic lifters, or tappets, as you've been told. You don't say if your car is a VL or VN, which was released in August 1988, but I'll assume it's a VL. The reason for the assumption is that the Nissan engine in the VL suffers camshaft wear and lifter rattle. The way to fix it is to replace the camshaft and lifters.

BEFORE the advent of bigger front-wheel-drive family cars from Toyota and Mitsubishi in the '90s, we mostly used rear-wheel-drive cars for towing. They are still preferred for towing because the weight over the rear wheels is an advantage. The recent popularity of all-wheel-drive cars, including 4WDs, has further clouded the towing issue. If I were to go on the round-Australia dream drive, I would take an all-wheel-drive. Not for the towing, but to get to those out-of-the-way tourist destinations that I couldn't get to with a two-wheel-drive car.