High/wavering idle
#1
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Year: 1998
Model: Cherokee
Engine: 4.0 L
High/wavering idle
My jeeps been overheating lately and after messing with a few things I decided to just take my thermostat out completely. At the same time I replaced my harmonic balancer pulley assembly.
Before doing any work my jeep would idle just below 1000 rpm in any gear.
Since doing the work, the jeep idles at around 2000 rpm on cold startup and eventually comes down to around 1500 rpm while idling in park or neutral and the idle will bounce back and forth between ~1300 and ~1600 rpm. It will drop to normal rpm's when in reverse or drive and be steady.
Is this the engine trying to heat itself up because there isn't a thermostat? Or is it something else and simply a coincidence?
Before doing any work my jeep would idle just below 1000 rpm in any gear.
Since doing the work, the jeep idles at around 2000 rpm on cold startup and eventually comes down to around 1500 rpm while idling in park or neutral and the idle will bounce back and forth between ~1300 and ~1600 rpm. It will drop to normal rpm's when in reverse or drive and be steady.
Is this the engine trying to heat itself up because there isn't a thermostat? Or is it something else and simply a coincidence?
#2
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Join Date: Jan 2013
Location: west chester, pa
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Year: 1999
Engine: 4.0
My jeeps been overheating lately and after messing with a few things I decided to just take my thermostat out completely. At the same time I replaced my harmonic balancer pulley assembly. Before doing any work my jeep would idle just below 1000 rpm in any gear. Since doing the work, the jeep idles at around 2000 rpm on cold startup and eventually comes down to around 1500 rpm while idling in park or neutral and the idle will bounce back and forth between ~1300 and ~1600 rpm. It will drop to normal rpm's when in reverse or drive and be steady. Is this the engine trying to heat itself up because there isn't a thermostat? Or is it something else and simply a coincidence?
#4
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Join Date: Jan 2013
Location: west chester, pa
Posts: 19,216
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Year: 1999
Engine: 4.0
similar problem would happen when u unplug the coolant temp sensor... So I would imagine that with the thermostat gone, the coolant would be too cold and trigger sorta same symptom
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