Holden Captiva Engine Problems

There’s a variety of ways a turbocharged engine can lose boost. You might have a problem with the intercooler or even something simple like a dirty air filter. Don’t rule out a fuel supply problem which is causing the computer to reduce boost to account for a lack of fuel.

But one thing that has been noted in these cars is a cracked or broken boost pipe. If that happens, the boost will be lost to the atmosphere before it can get to the engine. Black smoke from the exhaust is a common accompaniment to this problem.

There could be a thousand reasons for this to occur, but there’s one common problem that affects the turbo-diesel version of the Captiva which can create this very symptom. The trunking that takes the compressed air from the turbocharger to the engine’s intake system can split or crack, leading to a leak. When this happens, the engine doesn’t receive the turbo-boost it needs to make power and you wind up with a very sluggish vehicle.

Accompanying symptoms can include a hissing noise under load and lots of black smoke from the exhaust. It’s definitely worth a check as it should be pretty easy for a mechanic to spot and is a simple, cheap fix before you go looking for more complex causes.

This sounds like a fairly simple case of the engine setting up a harmonic vibration through the car. It’s not an uncommon thing and diesels are worse than petrol engines purely because they vibrate more, particularly at idle. By revving the engine slightly, you’re changing the frequency of the engine’s vibrations and moving them out of synch with what’s called the 'natural frequency’ of the rest of the car.

Why does it manifest at the steering column? Because the column is a long, flexible (in a micro sense) shaft that is far more prone to picking up vibrations than a short, more solid part of the car. Why is it happening now all of a sudden? Probably because there’s some wear in the car somewhere. Your call to change the engine mounts was a good one as these can wear and cause this very problem. But, equally, the wear could be in the exhaust system or one of the points where it attaches to the car, a heat shield, the torque converter, or maybe even a piece of the car’s sheet metal that has come loose and is moving slightly.

The quickest fix is to bump the idle one or two hundred rpm and see if that moves the engine out of the vibration zone at idle.

Start with the basics: Is there enough oil in the engine? Check the actual dipstick rather than any on-dash gauge or indicator, as the dipstick never lies. If the level is low, replenish it and you should be okay provided you haven’t already damaged the engine by running it almost out of oil.

The other thing to do is check the owner’s handbook to see if the light in question suggests low oil level or low oil pressure. These are two very different things, but they will both cause catastrophic engine failure if ignored.

If there’s oil showing on the dipstick, you really need a mechanic to look at the vehicle to determine whether it’s a faulty sender unit (that is making the light think the oil level or oil pressure is low) or whether there’s something more mechanical at fault. Low oil pressure can be caused by worn engine bearings, a blocked oil pick-up tube in the sump or even oil that has been contaminated by fuel or moisture and is no longer doing the job of protecting the engine. Diesel engines, in particular, are capable of producing sludge that can block internal oil passages and stop the flow of oil to where it’s needed.

What you haven’t told me is whether your car is a petrol or diesel Captiva. The two engines have very different ways of operating and both can make very different noises depending on what’s going on with them.

Diesel engines often have a fair bit of fuel pump noise which can increase as the car travels more kilometres and the pump develops a bit of wear. But whichever engine we’re dealing with, if the noise is at idle, then you’d really want to check the engine’s oil pressure. Oil pressure is lowest at idle, and low oil pressure can cause noises from the hydraulic lifters and even the engine’s crankshaft and pistons. Neither of those are what you want to hear, though, as they suggests some fairly major internal wear or damage.

You haven’t told me which engine is fitted to your car, but if it’s the turbo-diesel engine, then the cause may be a pretty simple one. This engine has a habit of splitting the plastic trunking that takes the pressurised intake air from the turbocharger to the engine’s inlet manifold. If that happens, the air is free to escape to the atmosphere, and doesn’t make it’s way into the engine.

That’s why you’ll hear a noise like air escaping (because that’s precisely what it is) as well as a lack of power, because the engine is not receiving all the boost from the turbo. You’ll probably also notice that the car is blowing more black smoke than it should.

The fix is a new piece of plastic pipe that should be well within the abilities of any workshop to fit.

Regardless of whether you use an additive, a car’s Diesel Particulate Filter (DPF) will still need to be cleaned (or regenerated) periodically as soot builds up in it. Short trips where the engine doesn’t get a chance to warm up properly, as well as extended periods of idling in traffic and stop-start running will all hasten this requirement.

In the case of the Captiva diesel, the best way to manually force a regeneration is to put aside an hour and go for a decent drive. The advice from Holden in the day was to travel at more than 50km/h and at more than 2000rpm (which may mean locking the car out of overdrive) for a minimum of 25 minutes. During this process, you should not allow the speed or revs to fall below those two figures which suggests finding a decent strip of freeway to carry out this process. You should also not turn off the engine at any point in this procedure.

The broad idea is to get the engine and exhaust hot enough for the filter to regenerate and clean itself. Experience suggests a couple of attempts may be needed to get this to happen as it should, and in fact, the car’s computer will give you several chances to produce the desired effect before the workshop beckons.

If, after 100km of this type of treatment, the DPF light on the dashboard hasn’t disappeared, the solution is a trip to a workshop to have the filter investigated and, potentially, hand-cleaned. Also, a mechanic can initiate a DPF regeneration via a scanning tool.

This looks like a classic case of a body computer that is in the process of dying. Any time you see random lights coming on, or the stereo switching itself on, suspicions are always that the body computer as the culprit.

This computer controls literally hundreds of functions from the wipers, climate control, lights, entertainment system, even stuff like the rear window demister and central locking. And when the computer starts to fail many of these functions can go haywire, which is pretty much what you’re seeing.

The tail-lights staying on and the stereo witching itself on are what’s draining your battery, but the body computer is very likely the root cause and probably needs to be replaced. But before you do that, try this: Disconnect the battery overnight and then reconnect it next morning. Sometimes (but not always) this swill reset the body computer and might stop it playing tricks. The fix might be temporary, but it’s definitely worth a shot.

Holden’s own service schedule for this model Captiva doesn’t specify a change interval for the differential oil. Instead, it recommends the oil be changed when required according to how the car is behaving. Which would suggest that your car is, indeed, ready for new differential oil.

As far as the scan goes, be sure not to confuse a sticking or non-engaging rear differential with the same behaviour from the centre differential. These are both technically differentials, but have vastly different roles to play. In the case of an electronically operated differential, the clutches can sometimes be replaced separately, but in any case, you need to go deep inside the differential, so while your mechanic is in there, have them check out the whole unit.

For a start, you might find it’s neither of those things causing the noise. You may have a worn tyre, poor wheel alignment or a faulty brake, to name just a few possibilities. That said, both your suspects are likely contributors to this type of noise.

In any case, there’s a simple way to tell whether a noise is coming from the driveline (engine and transmission) or from one of the wheel bearings. Drive the car at whatever speed is necessary to make the noise appear. If it gets louder as you apply throttle, there’s a good chance it’s driveline related.

But now, with the car still making the offending noise, drop the transmission into neutral (where it’s safe to do so, of course) and let the vehicle coast. This takes all the stress off the driveline and the engine should return to idle. If the noise is still present, then you have a wheel bearing or other problem linked to the wheels, brakes or axles, but not the engine or gearbox.