Skip the auto shop - Our mechanics make house calls

Q: Rough idling, hard shifting and shuddering at the highway

asked by on

I bought a previously owned car, which has some issues both while idling and driving. When the vehicle is not moving, like at the traffic light, it idles very roughly. Also, it is very hard to shift gears while I'm driving on the highway. The hard shifting is accompanied with shuddering and chirping sounds. What should I do?

A: Thanks for writing in about your 2002 Isuzu...

Thanks for writing in about your 2002 Isuzu Trooper. The rough idle may be due to the fuel injection system being dirty or having an engine vacuum leak causing a lean condition. The hard shifting and shuttering with the chirping sounds like you have an automatic transmission lock up converter problem and should have the transmission checked. I recommend having a transmission expert inspect your rough idling and hard shifting issue in order to make the correct repairs for this scenario.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Slight whining noise when changing up gears at higher revs or going up hill

The key diagnostic, which you have artfully captured, is "when the clutch is pressed". This narrows the diagnosis to either a failing clutch throwout bearing, or failing clutch pilot bearing. Both of these should have been replaced when the clutch...

Q: Kia Rio cranks but stutters, revs high but won't accelerate

This is not a common complaint and I would speculate the engine has a major vacuum leak or a mass air tube leak between the throttle body and the sensor. I can only recommend having a mechanic, like one...

Q: My third gear is grinding

This may suggest failing synchros. As you may know, when a clutch drags, it is not letting go of the disk fully which overloads the synchros and burns up the friction surfaces quickly. Synchros work by speeding up or slowing...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...