P0299 code on kid's car 2014 Chevy Cruze about 75K miles

nickb2

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Easy way to check, it is a on or off valve to prevent airflow. Energize, is it flowing on AND off, if so, bad valve slash solenoid.
 

JP

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So I checked the turbo wastegate lever. With it hooked up to the actuator, it doesn't move when I wiggle it. I disconnected it and the wastegate valve moves freely. The actuator rod and actuator have some tension on them when hooked up to the wastegate lever. You have to put some tension on the actuator rod to pull it out to reinstall it. As I understand it from the TSB, this means it's OK and passes that test.

When in park and revving the engine, it looks like the actuator lever moves just a little bit. I also checked all the vacuum fittings and hoses and they all look intact with no visible cracks.

I'm guessing this is about all I can do here without my garage stuff. Any other suggestions?
 

NickD

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Seems like the turbo is being blamed for other engine problems, like overheating the engine with that coolant leak, does have an aluminum head, can have cracks in it leaking coolant into the combustion chamber. Cruze also noted for poor made in China coils on plugs, spark plug gap should not exceed 0.025" because he spark in these cars is weak., also spark plugs not properly torqued with leaks blowing out that weak a spark.

Engine codes are at best a guess, unlike good military equipment, no secondary references are used.
 

JP

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I'm going to pressure check the cooling system today. Is that the same coil pack that's used on the Trax? I replaced one in my other son's Trax a while ago. Easy fix, but it only lasted as I recall 40-some K miles. POS.

Anyway, I guess Phoenix son can drive around without the turbo. He doesn't notice and doesn't really care. If there's coolant leaking into the engine, that's another matter.

So if I pressure check the system and find no external leaks, the only place it can be going is inside the engine, right?
 

JP

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So here's another question: If I clear the P0299 code then shut off the engine, then restart it, will the code set at idle or do I have to drive it...in other words engage the turbo boost...for the code to reset?

I was thinking, if the code resets at idle, how does it know there's an underboost? If it does reset at idle, does this point to a component of the turbo system that's likely responsible for throwing the code? Again, I don't know squat about turbo systems, but it seems logical to me that the system could only tell if there's an underboost when a condition exists...driving...that calls for a normal boost and that normal boost doesn't happen.

Of course, I know engineers don't think this way. They think, "Hey, let's have X code set if there's a problem with systems X, Y, Z, A, B and F."

I suppose there's other parts of the turbo system that can go bad without there actually being an underboost happening, hence the ability to set the code at idle.
 

billr

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I think your reasoning is correct: if the "under-boost" code sets only from idle operation it is a very ambiguous code, and the basic turbo rotating group may be fine.

If you do pressure check of the cooling system, be sure to do it with the engine cold. When hot, small external leaks will usually flash to vapor and not be visible.
 

nickb2

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If I clear the P0299 code then shut off the engine, then restart it, will the code set at idle or do I have to drive it...in other words engage the turbo boost...for the code to reset?
At idle, it wont code. Once you reset it, the ecm will allow finction to turbo, but for the ecm to know that, you need to drive in a particular manner. Meaning, You need to do a drive cycle. Once it codes, dont erase plz, I want the freeze frame at time of event plz. That way we can see at what demand engine was at.

Check list of things that cause under boost are air escaping from air inlets and outlets to amd from turbo to engine and intercooler.

A clogged intercooler will also cause underboost. These are easy to check with a smoke machine.

If the turbo threw raw oil everywhere, alot of that ended up in the intercooler, So cleaning that may solve this, but not the how. Which often leads back to a turbo.

Remember, fixing cars needs a sherlock holmes approach, once you eliminate the probable first, then whatever remains, however improbable, MUST be the truth.
 

nickb2

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A smoke machine is not readily available, but using shop air works also with a regulator and some soap and whatever.

Billr has used this before with very solid success.

Anybody remember the old days when you would say to your friend at the bar, go to the smoke machine and gets us a pack of marlboros. ;)
 

NickD

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In the military a carton was 90 cents, today it 80 bucks, had to find a less expensive way to get cancer.
 
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