Holden Colorado 2009 Problems

I think you’re on the right track by concentrating on the information being conveyed by the crank-angle sensor. But the problem is more likely to be a stretched timing chain rather than a dud sensor. The V6 engine in your Colorado is notorious for this problem and, when it happens, it throws the camshafts out of synch with the crankshaft. When the crank-angle sensor and the camshaft-angle sensor can’t agree that the positions of the crankshaft and camshafts relative to each other are correct, the problems start.

This lack of synchronisation is one of the things the crank-angle sensor is paid to look for and why it’s limiting engine speed or not allowing the engine to start at all. By clearing the fault code and disconnecting the crank-angle sensor, you’re stopping the error information being sent to the ECU and the ute starts first time (it’s probably taking a camshaft-angle reference when it can’t find the crank-angle information).

It sounds counter-intuitive that an engine would run at all with the crank angle sensor removed. Generally, without this sensor working properly, the fuel-injection system has no idea when to inject the fuel or fire the spark plugs. But sometimes – as in this engine – if the computer can't 'find' a crank angle input, it will take a reference from the camshaft angle sensor and use that to time the injection and ignition.

Even so, if the problem persists after two replacement sensors, it's probably fair to say this particular sensor is either not the root of your problem, or that or the engine's wiring is frying the new sensors as fast as you're changing them.

Either way, a trip to an auto electrician seems like the next logical step. Chances are a switched on sparkie will have seen this exact problem before and will know how to deal with it or at least take the logical steps to diagnose what's going wrong. Simply continuing to change bits and pieces is often an expensive way to solve a problem like this.

Here's a pointed question: Does your vehicle have an aftermarket trailer-brake system fitted? If it does, it's quite likely that the wiring passes through the cabin somewhere near where your leak is located. Unless this access hole is correctly sealed with the proper grommet, there's every chance water is getting in at this point.

Other likely suspects for this include roof mounted aerial holes, roof rack attachment points and even worn or damaged window and door rubbers.

The recommended service interval for this vehicle is every 10,000km. Roughly speaking, every second service is a bit more involved, so that suggests it’s more of a `major’ service. Either way, skipped services on a vehicle like this will be false economy in the longer term.

On the timing belt front, there’s good news and bad. The good news is that both the turbo-diesel and petrol V6 versions of the Colorado both use timing chains, so there’s no need to change a timing belt. The bad news is that the petrol version uses the Alloytech V6 which is renowned for its ability to stretch its own timing chain to the point where it needs costly replacement. This is a known fault with this engine.

It’s not likely to be a burned valve, as the engine would be running roughly if it were. It could be the tappets. Next time you start the engine lift the bonnet and take a moment or two to listen to the engine to see if you can get an idea of where the noise is coming from.

Try disconnecting and reconnecting the battery. If that doesn’t do it take it to a Holden dealer, as the body computer probably needs to be reset.

You should take it back to the people who installed the gas system, as something is amiss with it.