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Discussion Starter #1 (Edited)
I am hoping some of you Cruze mechanic extraordinaires out there can help me make a diagnosis.

My Son's recently purchased 2010 Cruze has some issues. The first symptom was the injector warning flashing on the dash and blowing a lot of white smoke about 3-5 minutes after starting engine (once it started to warm). The Holden dealer diagnosed it as injectors and so we replaced the injectors. During the injector swap we noticed that all 4 old injectors had a lot of oil on their nozzles which did not seem right. On first start, it continued to blow white smoke but seemed to be clearing (over 10 minutes of running) and the injector light disappeared. We then started to rev the engine and almost immediately the engine ran away. That is, it RPMs went crazy high, well beyond the redline. We turned the ignition off immediately and luckily, the engine stopped (Runaway engines often can't be stopped and rev at full fuel until they self destruct). So we disconnected the air intake at the aircleaner so we could choke/stop the engine manually if it ran away again. We tried running the engine one more time and unfortunately, it ran away again so we choked it to a stop with a large rag in the intake pipe. So I would like some guidance to diagnose the issue. Here are my initial thoughts/ideas:

1. I think the injectors should be dry not covered in oil? So where could the oil be coming from, past the oil rings? blown head gasket? cracked head?
2. I think The white smoke has to be moisture entering the combustion chamber? or exhaust? If it is getting into the combustion chamber, where could it be coming from? blown head gasket or cracked head? Not sure there is anyway moisture could be entering the exhaust???
3. We also noticed the engine oil seems very thin and is overfull. Could diesel be getting into the engine oil? ( I will drop and replace the oil today).
4. I am thinking the Running Away issue could possibly be caused by the thin engine oil entering the combustion chamber and the engine is using it as fuel therefore overfueling and running away.
5. We don't know the history of the car but perhaps it has been overheated or run low on oil.

I personaly am leaning toward blown head gasket and/or cracked head but before I remove the head, I would greatly appreciate some guidance from the group.
 

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White smoke is coolant being burned in the combustion chamber. I’d start by looking for a blown head gasket.

But you should also be looking for fluid in the intercooler. That is a likely cause of runaway engine.
 

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How many km on the engine. Is the oil level high as this to can cause a runaway diesel. If the rings are worn you can get diesel fuel raise the oil level and cause this to happen.
 

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Bad injectors can often allow diesel to enter the crankcase which, as you noted, can lead to runaway if left unchecked.

When the injectors were changed did you also drain/fill the oil to proper spec?

My Cummins injectors went bad and I had a couple of liters oil overfill as a result. Bigger displacement engine (3x the Cruze oil capacity) so no runaway however.
 

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These days runaways are almost always turbo related like 95% of the time. Injectors will never cause a runaway. Not on these newer cars, they just don't have the flow. Regulator fail, maybe, but it would all need to fail perfectly.
 

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Discussion Starter #7
Hi Rivergoer, We have just dropped the engine oil and it had at least 2 litres more than it should have. Also the oil is very thin even though its cold which would indicate it has a lot of diesel mixed with the oil. We will fill it to specification and see how it runs. Will report back shortly.
 
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