Holden Colorado Problems

It’s very difficult to diagnose problems over the phone, just as it is via this website. But, I’d be taking the vehicle straight back to the mechanic in question, because whatever is wrong is going to be fairly major.

In the majority of cases, an engine with a broken crankshaft won’t run. In fact, it won’t even turn over. Sometimes, it will still run, though, and the symptoms you’ve described are spot on for that. Either way, a broken crankshaft is one example of what’s called catastrophic failure and a new crankshaft (at the very least) is the usual result.

But those same symptoms can also be the result of a loose harmonic balancer. And here’s the clue: The harmonic balancer has to be removed to replace the front crankshaft seal (which was done the day before the problems started). If the balancer is not reinstalled correctly, it can start to wobble, tear up the new seal and make all sorts of noises and vibrations. The bad news is that often, the wobbling balancer destroys the end (called the snout) of the crankshaft in the process, so even though the crank is not broken or snapped per se, it may still need to be replaced. It does seem like a fantastic coincidence that the balancer started wobbling the day after it was removed and refitted. That said, if the crankshaft has failed, then a coincidence is precisely what it might be.

I’ve actually experienced this on a brand-new Colorado (during an evaluation drive, no less). In this case it turned out to be a couple of loose fasteners in the front end, which were fixed quickly and permanently. In your case, though, it seems as though even with everything checked and tightened, the noise is still there.

So maybe it’s not something as obvious as a loose coupling or fitting. Maybe you’re looking at noisy shock absorbers. Sometimes these components can contribute a clunk, but it’s usually when they’re worn out, not on a six-month-old vehicle. Does the noise occur in a straight line or with some steering lock applied? Perhaps the steering lock stops are the culprits. I’d be putting the vehicle back on a hoist and checking that everything from the engine mounts to the cross-member and the steering rack to the transmission mounts are torqued to the correct values. Don’t rule out silly things like a loose tub or tray, either; sometimes a clunk in the rear of a vehicle can be transmitted down a chassis rail to sound like it’s coming from the front somewhere.

This is a weird one. I spoke to two different Holden service workshops (former Holden dealers) and the consensus was that the reverse lights on your car are not on a separate fused circuit. Certainly there’s no mention of such a fuse in the owner’s manual. That means, then, that the reverse lights share a circuit with other functions at the rear of the vehicles, possibly the tail-light circuit. Beyond that, nobody could be specific.

In turn, that suggests that it’s not the fuse at fault because, if it was, the whole rear of the vehicle would be blacked-out. Which brings us to the possibility that the problem, rather than being a blown fuse, is rather the adjustment of the switch that recognises the car is in reverse and turns on the lights and camera. This is located on the side of the transmission and, if it’s out of alignment or showing wear in its contacts or wiring, could lead to the problem you have.

There are three classic causes of a sinking brake pedal. The first is a worn out brake master cylinder that is allowing brake fluid back past the actuating piston. The second is a leak somewhere in the braking system, either a caliper itself or a brake line or union and, the third is an ABS system fault where the ABS pump isn’t working properly, usually due to a low brake-fluid level.

Regardless of the cause, there’s no `acceptable tolerance’ for a brake pedal that slowly sinks towards the floor. A braking system in good working order should be able to hold the brake pedal at the same level more or less indefinitely. Any sinking is bad news and is a serious safety issue. I wouldn’t even have the car towed to a workshop; it’s simply not safe to drive.

You’re on the right track by asking about the gear-stick and its linkages; either of those two things is almost certain to be the cause of your problem. The gearstick itself needs to pivot in two planes, so there’s always scope for wear to develop in those joints and create the sloppy shift action you’re experiencing. In fact, because the shifter on your car bolts directly on to the gearbox – with no external linkages – wear in the shifter pivots is a very good bet as the cause.

You can remove the shift lever, take it apart and replace the bushes that allow the shifter to move and select each gear. That should tighten up the shift action and give you much better feel for what’s going on. The other possibility is that the shifter has become loose where it bolts on to the gearbox, or the rubber gasket that sits between the shifter and the transmission has perished or failed, allowing movement to occur.

The symptoms you have certainly suggest an engine with far too much blow-by (combustion pressure escaping past the piston rings and into the crankcase). Sometimes, the same symptoms can be caused by a crankcase ventilation system that isn’t working properly, but it’s often blow-by that’s the cause. That’s usually the result of internal engine wear which, at 290,000km and counting, is hardly out of the question.

Basically, the observations you’ve made regarding crankcase fumes are about as far as you can go without actually performing a compression and cylinder leak-down test. The good news is that these tests aren’t overly complicated and don’t take long, but they will give you a vastly more accurate idea of what’s going on inside the engine. Oil in the intercooler can also be a sign of this sort of wear, but, as you’ve been told, can also be the fault of blown turbocharger seals. Either way, it sounds like your engine is due for a freshen up in the name of reliability and clean running.

As with any four-wheel-drive that is approaching middle-age, you need to treat every Colorado on its individual merits. How has it been driven? Has it been used as a work truck? Has it spent every weekend off-road?

Beyond that, the Colorado is subject to the same concerns that challenge all owners of modern, common-rail diesel engines. Those start with the soot filter which can clog up and require manual cleaning. The solution is to make sure you do at least one decent freeway journey every three or four weeks as a means of allowing the filter to regenerate as it’s supposed to.

The other thing that catches many owners out is a build up of black gunge in the engine’s inlet tract. The black ooze is a combination of oil mist from the crankcase ventilation system and soot from the exhaust (a modern engine consumes a proportion of its own exhaust gasses as an emissions-reduction measure). When these two compounds mix, the black, sticky murk is the result. If it’s bad enough it can trigger a check-engine light on the dash and can lead to poor running and fuel economy. Left long enough, the whole intake system will need to be removed and manually cleaned. An aftermarket oil separator stops this is it traps the oil mist before it can enter the engine and is a good addition to these vehicles.

If replacing the actual sensor doesn’t fix the problem, then you could be looking at a problem with the wiring that connects that oxygen sensor to the car’s on-board computer. Did the mechanic that changed the sensor check the condition of the wiring? This equipment all lives very close to a very hot exhaust system, so damage from that is not unknown.

There’s also a chance that the computer itself is throwing up a bogus fault code when it’s interrogated. Temporarily swapping the computer for another one is a reasonably simple way to rule this out. There’s also a chance (and it’s more common than you might imagine) that the brand new oxygen sensor you had fitted was a dud straight out of the box. This has definitely been known to happen, and it’s the first thing some experienced mechanics will think to check.

A better idea would be to fix the sensor that’s creating the false alarms. That will probably be simpler and quicker than finding the right wire to cut or fuse to pull out, as well as maintaining the car’s legality. A car that doesn’t have all its safety equipment functioning properly is, technically, unroadworthy and if that fault can be blamed for any injury in a crash, then you could be in real trouble in a legal and insurance sense.

Don’t forget, too, that a car such as yours will usually have a sensor to determine whether the seat-belt is secured and another to determine if the passenger’s seat is occupied. Either of those could conceivably be causing your false alarm.

On the lower-right corner of the dashboard, you’ll find the rotary switch that controls the headlights. On the same switch panel (just to the left of the main headlight switch) are a pair of sliding controls that control the headlight aiming (the right-hand slide) and the dashboard-light brightness (just to its left).

When the car’s headlights are turned on, the dashboard lights are automatically dimmed, and sometimes this provides insufficient light to see the gauges clearly in bright daylight. But by holding the adjustment slide in the up position, you can turn the dashboard lights to their brightest level of illumination.