Holden Colorado Diesel Problems

It’s quite common for an oil pressure sensor to develop a fault where it sends the incorrect information to the car’s computer which then lights up the low oil pressure warning. But since you’ve already replaced this sensor, maybe that’s not the case here.

The big clue is that fresh oil and filters improved things a little, which makes me think it’s a genuine oil pressure problem. I also reckon you might be bang on the target by suggesting that it’s an oil pick-up problem. The oil pick-up lives in the sump of these engines and if the pick up inlet is blocked or partially blocked by sludge from the engine, it can fail to suck up enough oil to maintain the correct oil pressure. The higher the revs, the bigger the pressure shortfall. Failing that, sludge can block the various oilways around the engine that allow the oil to get to where it needs to be. Either way, you wind up with insufficient oil pressure and flow and risk destroying the engine.

I wouldn’t have thought 136,000km on an engine would have it showing signs of oil sludging, but that’s based on proper maintenance (not to mention that even modern diesels are filthy things inside). Have you owned the vehicle from new? Has it always been serviced correctly and promptly? If it’s been neglected (even one skipped oil change) it can develop the deadly sludge and it can be all downhill from there.

Possibly the best course of action would be to remove the sump and check the oil pick-up strainer for signs of gunk and build up. If that’s okay, then two or three quick oil changes (say, every 1000km) with an engine oil designed for trucks (which has lots of detergent as an additive) might clean things up internally enough to keep the oil pressure light at bay.

The other thing to try would be a new oil pump. Like any engine component, these can wear out over time and kilometres but, again, I wouldn’t expect to see significant wear on one that’s just 136,000km old. Other causes to consider would be excessive bearing clearance in the engine (due to wear or damage). In that case, a tear down and rebuild is the best option, because worn engine parts don’t repair themselves.

Yes, it is a common rail diesel engine.

 It could be that they’ve replaced their pumps and the flow was too high for your car. Try tempering the flow next time you fill at that servo, and to be sure fill at another servo to see if it does it at other stations or it’s just related to the newly renovated one.

It's not an unusual requirement with a diesel with a DPF. The DPF normally cleans itself automatically without you even knowing, you don't have to do anything. But if you don't do the sort of driving that invokes the automatic regeneration you then have to take action as recommended by Holdens to do it. Diesels don't work at their best when tooling around the ‘burbs at low speed, and anyone buying one with that sort of driving routine should ask their dealer about the suitability of the vehicle for them.

I agree that two weeks is too long to have to wait, the dealer’s workshop is poorly organized if he has to wait that long. I wouldn’t be concerned about driving the car of the light is not illuminated, if it comes on again, stop and turn the ignition off and on again. That might be enough to reboot the computer and keep you going. If it’s coming on regularly then certainly have the cause investigated.

It looks like you’ve reached a stalemate. Ryco has told you there is nothing wrong with its filter and are obviously happy to leave it at that. I suggest you sit down with them and discuss your concerns face to face. If that doesn’t achieve a resolution, then take it to consumer affairs.

No there appears to be something amiss with it, so get the dealer to check it again. If that doesn't resolve the issue take it to an independent diesel engine mechanic and have them check it for you.

The Colorado will run on Biodiesel, but the issue is that it cleans vanish and other deposits from the fuel system when you switch from regular mineral oil diesel. If you were to switch you should run a replace the filters after running a tank of biodiesel through it. If you do that you should be ok.