For about a month now I have been experiencing a rough idle where the rpms consistently go up and down between 700 and 800 rpm. This only happens in drive with the brakes pressed. This also goes away if I shift the gear selector to manual mode. No check engine light. Car is 2011 LS with 1.8 LUW engine and automatic trans. Any ideas on this would be greatly appreciated.
Rough/fluctuating idle only in drive while brakes depressed.
Snappa
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For about a month now I have been experiencing a rough idle where the rpms consistently go up and down between 700 and 800 rpm. This only happens in drive with the brakes pressed. This also goes away if I shift the gear selector to manual mode. No check engine light. Car is 2011 LS with 1.8 LUW engine and automatic trans. Any ideas on this would be greatly appreciated.
On the 1.8L I'm not 100% sure. I'd be guessing, but pressing the brakes is essentially changing vacuum through the master cylinder. I'd be looking for air leaks. My 1.4L was surging with an oily throttle body. Cleaned it and surging went away. However the 1.4L being a turbo is more inclined to ingest oily air. However the 1.8L must have some sort of PCV return system.
Well, it could be several different things. Or a combination of issues. I'd recommend you start with the easy to to do stuff.
1. Carbon02 has a good point, checking for a vacuum leak is a really good idea.
2. Check the spark plugs. Old plugs with the gap eroded could be it. If so new plugs would be in order.
3. Clogged fuel injector. Get a good fuel injector cleaner (something with PEA in it), this might do it but the results won't be immediate.
4. An extremely plugged engine air filter.
Hopefully it is one of the above. Keep us updated.
1. Carbon02 has a good point, checking for a vacuum leak is a really good idea.
2. Check the spark plugs. Old plugs with the gap eroded could be it. If so new plugs would be in order.
3. Clogged fuel injector. Get a good fuel injector cleaner (something with PEA in it), this might do it but the results won't be immediate.
4. An extremely plugged engine air filter.
Hopefully it is one of the above. Keep us updated.
But why would it go away when put into manual mode? For example im at a stop and I shift the lever over to M1 and it starts to run normal again.
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I've been putting mine in Manual at stop lights for a long time now. It's a habit. Why it stops while in Manual is beyond me. I can put it in Manual and no vibration and once I put it back into Drive, the vibration comes back. For my car, vibration seems to only happen if I'm using A/C or Defrost. If I'm not using the fan at all, I don't believe it vibrates. I've been so fed up with it I've just given up.
Edit, maybe this will provide some help for you?
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Crawl under your car with a hammer and tap your cat and listen for “sand”, from past experiences with other cars when the cat starts clog it starts to bog things down, with a load things bog down. It could also be an intake man. or maf sensor going out but those usually throw out a code
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I'm not too sure what it is. When I change the oil next I'll give that a shot.
Also, I don't know what (if anything) this means, but when I have it in Drive and use the Parking Brake, it doesn't vibrate/shake, but once I press the Brake pedal the vibrating/shaking starts.
Also, the car doesn't vibrate/shake nearly as violently when the engine is cold. As the temperature gets closer the normal spot (just before halfway) is when the vibrating/shaking gets pretty rough.
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I'm not sure it could be the rotors because the car only surges/vibrates/shakes when it's stopped and the brake pedal is pushed. Once I let of the brake pedal, the surges/vibrates/shakes doesn't happen. I believe the service bulletin I posted above is what I'm having an issue with. I'm just too chicken crap to call and find out the cost of repair, lol. I'm afraid if they say $2,000 I'm gonna drop the car off at a salvage yard! ahaha
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Have you checked your electronic brake booster pump it could short and mess with the ignition i mean even the harness has problems
Was this ever resolved??? I am having similar issues!!
Rough idle in drive. SOMETIMES Chevy Cruze 1.8L 2014 LS (65k miles)
I have had this car since about 35k miles has been great doing! All recommended maintenance was kept up to date etc. Then an engine code for the thermostat appears and that day seemed to be the start of all my problems HA. Replacing the thermostat and other due maintenance was in order..
After replacing the thermostat or honestly maybe even before said repair the rough idle began.
EVERY NOW AND THEN chunking and jumping like a wild big cammed car, putting the car in any other gear other than drive- the problem will go away.
On normal days it is not as smooth as brand new but fairly good. On good days she'll idle perfectly like straight from the lot. THIS IS AFTER REPAIRS MENTIONED BELOW
Super picky...(possibly the weather/angle of car/car temp)
Things I have noticed are- usually happens when the car is at optimal operation temp and it seems the idle RPM drops a tad when the shaking occurs and apply a little bit of gas will get the shaking to stop.
MAF/fuel pump/gas cap are next I guess with a extra eye on vacuum leaks/exhaust leaks?
MAINTENANCE(mostly OEM replacements)
~Thermostat/thermostat housing(cracked and was replaced with a metal one. Only part that I used that was not OEM. The Throttle body heater inlet pipe that sits on top of the thermostat broke so that had to be replaced. SUPER brittle)
~Valve cover(I found what seemed to be a pea size of oil (or fuel) on top of park plugs 2 and 3 replacement fixed this issue since)
~Spark plugs, coil pack
~Water pump(whining/possibly failing)
~Serpentine belt/serpentine tensioner
~Timing belt, timing belt tensioner/idler (heard a ticking noise from this side of the engine and got lucky the idler bearing was shot and when shook rattled. when replaced ticking went away)
~The entire air intake manifold(Had issues with the tuning valve arm coming off, then the actuator not moving so even went to the lengths of replacing the actuator before the entire manifold... This did not work as I kept getting NEW engine codes for the air intake manifold since its been replaced the code has gone away)
~The back VVT sensor (dunno why lol, hoping for blind luck?)
~Knock sensor(under the air intake manifold, why not)
~The coolant reservoir(cracked).
Motor mount looked in okay shape. MAF and throttle body have been cleaned. Fresh oil with no visible leaks/oil looked good when drained. No coolant leaks either after reservoir replacement (pressure tested)/also coolant looked good with the multiple times I had to drain it/bleed it. No engine codes. Do not know if a exhaust leak is present however... *
Definitely a beginner tree shade google mechanic so any advice would be appreciated.
Thank you!
Rough idle in drive. SOMETIMES Chevy Cruze 1.8L 2014 LS (65k miles)
I have had this car since about 35k miles has been great doing! All recommended maintenance was kept up to date etc. Then an engine code for the thermostat appears and that day seemed to be the start of all my problems HA. Replacing the thermostat and other due maintenance was in order..
After replacing the thermostat or honestly maybe even before said repair the rough idle began.
EVERY NOW AND THEN chunking and jumping like a wild big cammed car, putting the car in any other gear other than drive- the problem will go away.
On normal days it is not as smooth as brand new but fairly good. On good days she'll idle perfectly like straight from the lot. THIS IS AFTER REPAIRS MENTIONED BELOW
Super picky...(possibly the weather/angle of car/car temp)
Things I have noticed are- usually happens when the car is at optimal operation temp and it seems the idle RPM drops a tad when the shaking occurs and apply a little bit of gas will get the shaking to stop.
MAF/fuel pump/gas cap are next I guess with a extra eye on vacuum leaks/exhaust leaks?
MAINTENANCE(mostly OEM replacements)
~Thermostat/thermostat housing(cracked and was replaced with a metal one. Only part that I used that was not OEM. The Throttle body heater inlet pipe that sits on top of the thermostat broke so that had to be replaced. SUPER brittle)
~Valve cover(I found what seemed to be a pea size of oil (or fuel) on top of park plugs 2 and 3 replacement fixed this issue since)
~Spark plugs, coil pack
~Water pump(whining/possibly failing)
~Serpentine belt/serpentine tensioner
~Timing belt, timing belt tensioner/idler (heard a ticking noise from this side of the engine and got lucky the idler bearing was shot and when shook rattled. when replaced ticking went away)
~The entire air intake manifold(Had issues with the tuning valve arm coming off, then the actuator not moving so even went to the lengths of replacing the actuator before the entire manifold... This did not work as I kept getting NEW engine codes for the air intake manifold since its been replaced the code has gone away)
~The back VVT sensor (dunno why lol, hoping for blind luck?)
~Knock sensor(under the air intake manifold, why not)
~The coolant reservoir(cracked).
Motor mount looked in okay shape. MAF and throttle body have been cleaned. Fresh oil with no visible leaks/oil looked good when drained. No coolant leaks either after reservoir replacement (pressure tested)/also coolant looked good with the multiple times I had to drain it/bleed it. No engine codes. Do not know if a exhaust leak is present however... *
Definitely a beginner tree shade google mechanic so any advice would be appreciated.
Thank you!
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51 Posts
I resolved mine by replacing the motor mount on the passenger side.
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