Lumpy idle....wtf
#1
Lexus Champion
Thread Starter
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This morning I find the car has lumpy idle after it has been warmed up.
What gives? Temp was around 27F.
Here are couple of shots....One with car in N. No issues there.
When in 'D', however the idle is very lumpy. The whole cabin was vibrating.
What could this be?
What gives? Temp was around 27F.
Here are couple of shots....One with car in N. No issues there.
When in 'D', however the idle is very lumpy. The whole cabin was vibrating.
What could this be?
#4
Lead Lap
iTrader: (1)
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I had this too, it was about -23C and my engine was shaking. like actually shaking. But it settled when it warmed up and hasn't happened since. I'm not sure what that means if it was happening while it was warm though. Might want to take it to dealer if you're on powertrain.
#5
Pole Position
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I had this too, it was about -23C and my engine was shaking. like actually shaking. But it settled when it warmed up and hasn't happened since. I'm not sure what that means if it was happening while it was warm though. Might want to take it to dealer if you're on powertrain.
http://wiki.answers.com/Q/What_is_th...t_of_motor_oil
#7
Lexus Champion
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there is a diff of 200 between the two pictures. Of course I cannot take pictures of the vibration, so this was the best I could provide.
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#12
Lexus Champion
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I figured it out....damn EPA software issue.
This morning it was freezing cold so I let the car Idle for about 15 minutes while I had my breakfast before going off to work. Apparently, as you idle more, the engine trims the fuel and causes idle to drop (from my observations).
For example, when I come to a stop gently, the idle stays at 1000, ready to take off if needed. but after about 5 seconds, the rpm drops a a little, to about 750, and then some more to 650.
Given that this morning it was idling for about 15 minutes, the engine was idling at 550 (in D) rpm making it lumpy.
Not fun at all.
As I drove back this evening to home, I did not idle the car at all when taking off from work. The idle behaved just fine and the temp was 30F.
This morning it was freezing cold so I let the car Idle for about 15 minutes while I had my breakfast before going off to work. Apparently, as you idle more, the engine trims the fuel and causes idle to drop (from my observations).
For example, when I come to a stop gently, the idle stays at 1000, ready to take off if needed. but after about 5 seconds, the rpm drops a a little, to about 750, and then some more to 650.
Given that this morning it was idling for about 15 minutes, the engine was idling at 550 (in D) rpm making it lumpy.
Not fun at all.
As I drove back this evening to home, I did not idle the car at all when taking off from work. The idle behaved just fine and the temp was 30F.
#13
Lexus Test Driver
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I wouldn't go as far as saying it's an EPA software issue. Several things come into play. Oil temperature, the amount of time the car had been off. Frozen condensation inside the exhaust system. Even the battery can play a role in how the car responds in the cold morning.
#15
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You shouldn't leave your car idle for more than 10 seconds. It's not good for your engine.
http://www.thehcf.org/antiidlingprimer.html
http://www.thehcf.org/antiidlingprimer.html
Bringing an engine up to temp was important due to its construction.
As you have several materials it is constructed of, each heat up and expand at different rates.
Cast iron blocks, and aluminum heads are often a problem, as the uneven heating has been known to blow head gaskets or even crack the heads themselves.
Rapid heating is also attributed to premature metal fatigue, or warping of parts due to localized hot spots.
Also, a cold engine has massive clearances in all its critical areas (bearing journals, lash adjusters and such) that should be much tighter in tolerances before placing undo stress on them.
In all my years of mechanicing, the general rule has been to always bring the engine up to temp before placing stress on its componants.
2cents
Vince