# Shaking issue stumps 3 mechanics



## scot_stuf (Feb 27, 2018)

1. 2011 Cruze Eco 1.4L, Standard Shift
2. 60000 miles
3. No warning lights, no codes
4. NJ
5. Coming to a stop, in neutral, the engine vibrates more than usually. Started last week, had an appointment at my mechanic yesterday, picked the car back up today, problem isn't fixed. I don't know enough about motors to be sure, but I could see this vibration called rough idle. 

Here's a description of the testing I did:
I came to a stop at a stoplight, for me I shift into neutral, let off the clutch, and brake while coming to a stop.
While stopped, the car vibrates. Press the clutch, shift into any gear, vehicle stops shaking. Shift back into neutral, vehicle starts shaking again. Release clutch, still shaking.
Its February in NJ, so the AC is not on, but I did test it with no changes.
Mechanic shop had no clue at first, so they did some research, they came to the conclusion that it was the PCV, so they replaced the valve cover. They couldn't replicate the problem after that, so they figured it was fixed. They also checked my vacuum hoses, and monitored the spark plugs for misfires before the replacement. I picked it up, and while driving home, the problem didn't happen for quite a while, but did eventually start up again.

I spoke to my uncle who is a retired mechanic, and he had never come across this, though suggested a bearing somewhere in the transmission area (sorry forgot exactly the part he said), told me to have the shop check for particles in the transmission fluid when I bring it back in.

I don't know if this makes a difference but just before the shaking issue started, I personally replaced the battery, nothing odd happened during the change.

6. USA
7. LHD


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## chevy626 (Sep 11, 2017)

What about your motor or trans mounts, have you checked on those?


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## Blasirl (Mar 31, 2015)

Just from your description, it seems as if the clutch/throw-out bearing or whatever takes its place nowadays is off balance for some reason. As I have never worked on a manual newer than 1982, I am not the expert though.


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## ProDigit (Aug 31, 2015)

Strange.
Mine would stop shaking in Neutral but shakes in gear, and when that's the case, it's time for an oil change.
Especially if the mechanic gave it regular dino oil, or 5W30 non-dexos, I might need to change the oil faster than the usual interval.

It appears your engine is shaking while under no load.
I wonder if the engine mounts are worn?
Or perhaps there's some loose wiring making noise (but there's no real shaking going on)?
How much is the RPM at idle? Does it go below 700RPM? If so, it's maybe time for an injector and throttle body cleaning.


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## Tomko (Jun 1, 2013)

Flywheel? @obermd @jblackburn


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## scot_stuf (Feb 27, 2018)

Thanks for all the responses! I don't know if they checked the motor mounts, that wasn't mentioned on the receipt. 
I only just did the oil change a couple of months ago, so it shouldn't (haha) be that.
I didn't note the RPMs, though it didnt feel like it was abnormal or I would have checked there, I will look the next time I take it out.
I will give the shop all the suggestions when I drop it back off, they are currently working on another car of mine, so I'll be swapping it either tomorrow or Thursday. If anyone else thinks of something let me know!

Edit: Took it out just now, and yes! The rpms are dropping to 700ish while the "shaking" is going on, when I shift into gear the rpms rise to 1000, shift back to neutral, they drop again to 700 nice catch, I hope this helps!


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## jblackburn (Apr 14, 2012)

Yes, the Cruze bumps RPMs when you let the clutch out. That may be the cause of the shaking subsiding.

It sounds rather like your dual mass flywheel locked up (there are essentially weights and the halves of the flywheel rotate back and forth to try to quell engine vibrations. My entire car shook pretty violently at idle when mine did, but then was fine at higher engine speeds. It also made quite a bad knocking noise just off idle when acting up other times.


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## scot_stuf (Feb 27, 2018)

There's actually no odd noises, car sounds perfect. Also, unless that video was shot with high end auto-stabilization, its not the same issue. The car is rumbling like its heading towards a stall, if there wasn't an engine issue freaking me out, I'd say the vibrations felt good, like a massage chair lol.


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## jblackburn (Apr 14, 2012)

scot_stuf said:


> There's actually no odd noises, car sounds perfect. Also, unless that video was shot with high end auto-stabilization, its not the same issue. The car is rumbling like its heading towards a stall, if there wasn't an engine issue freaking me out, I'd say the vibrations felt good, like a massage chair lol.


Wasn't shaking in the video; just noise and some vibration at low RPM. The two didn't really happen at the same time.

Put a high load on it in an upper gear (eg climbing a long hill at highway speed without downshifting). Mine would almost act up in that scenario. Actually stalling the car or reversing uphill would often set it knocking too.


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## 91794 (Mar 25, 2015)

based on symptoms, if it isn't a motor mount, seems it's gotta be a clutch-plate or broken clutch bearing or flywheel. 
so.... time for new clutch. if you gotta open it you should just replace it, ya? 
i understand it's not uncommon for clutches to fail due to parts breaking instead of wearing. 

to test for motor mounts, open hood, have buddy stand NEXT TO THE CAR and observe/video engine while you do a mini-brake-stand in 1st gear via clutch plus heel-and-toe. Or apply some forward torque with front bumper flush against a strong building/post, so car cannot move forward. For this sort of test, if the engine "jumps" vertically or horizontally or sideways when you do the brake-stand or try to move-forward-against-an-immovable-object, that is a way to see the effect of a bad motor mount without removing the engine to inspect it. 

I understand that the correct behavior for such a test is that the motor will appear to twist in place rather than "jumping". 
There can probably be model to model variations in the results of such a test so it might be nice to do the test on your car plus another/new cruze with same engine to see if the two engines twist the same way for the same test.


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## snowwy66 (Nov 5, 2017)

When you're stopped at light. Or in the parking lot or something. Hold the brake pedal down and slightly press on the gas pedal to raise rpms up slightly. What rpm does it take to eliminate the vibration. And what's the spec. rpm supposed to be?

Idle too low could defenitly cause a slight vibration.


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## scot_stuf (Feb 27, 2018)

Well, its out of my hands for a bit, the shop has it again to check all the things you've all mentioned, I hope they figure it out. Thanks again for all the input!


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## ChevyGuy (Dec 13, 2014)

jblackburn said:


> It also made quite a bad knocking noise just off idle when acting up other times.


I'd imagine that depends on how it failed. A knocking sound would probably be the dual mass "banging against the stops". A dual mass that's "stuck" (become single mass) may not make any sound, but it won't dampen the vibration like it should.

I think dual mass is still a bit "exotic" so I could see it puzzling some mechanics.


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## scot_stuf (Feb 27, 2018)

Well, it seems to be fixed. And in the end, it seems it was the throttle body, however, it was apparently very clean, however, the plate inside had some spacing around the outside of it, creating gaps, and the plate was also loose. New throttle body and it feels fine.


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## scot_stuf (Feb 27, 2018)

Spoke too soon... after 2 weeks of bad weather had me driving my Jeep, I jumped back into my Cruze to find the vibration again... More and more I feel like its a normal rumble, just that the vehicle is idling at too low of an rpm or something like that, it's been between 700-800 idle in neutral.


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## jmlo96 (May 2, 2015)

I think what you are describing my Cruze does too. I have a 14 1.4 LT manual. Since maybe when it was new, if I put it in neutral and let the clutch out it will idle weird sometimes for a second or 2. It's like it tries to take the RPMs down too low then bumps it up. It idles totally fine after that. It's like the ECU just needs the idle parameters adjusted. I'm not sure if this is what you are describing but I thought it might help.


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## joshuab (Apr 16, 2014)

OP has the flywheel been checked & confirmed not the issue? This sorta sounds like your issue, but not an expert in this, but from your description this maybe it.


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## Schkaddy (Jul 2, 2019)

ProDigit said:


> Strange.
> Mine would stop shaking in Neutral but shakes in gear, and when that's the case, it's time for an oil change.
> Especially if the mechanic gave it regular dino oil, or 5W30 non-dexos, I might need to change the oil faster than the usual interval.
> 
> ...


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## Schkaddy (Jul 2, 2019)

So do you know now? What was the reason?


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