Skip the auto shop - Our mechanics make house calls

Q: 2001 Mitsubishi Montero Sport running rough on idle

asked by on

2001 Mitsubishi Montero Sport 3 liter, 120,000 miles. Just had new timing belt, utility belts, water pump, sparkplug, wires and body throttle removed and cleaned. It runs rough on idle. Why?

A: Take it back to whoever did that work--they...

Take it back to whoever did that work--they did a crappy job. There are so many things that can go wrong. When you are changing all that stuff and replacing the timing belt off, odds are that the timing belt wasn’t put on and timed right. Those engines have overhead cams that are very hard to set.

If the mechanic didn’t have very special tools to hold those cams in place when he put the new belt on, a lot of times, they would move one tooth and one tooth is exactly what is going to make it run like that. Take it back and let them fix it or you can get your money back and go someplace else, because this is a very involved job and odds are there’s a tooth off on the timing belt. I see this all of the time. You can have this verified by having a technician, such as one from YourMechanic, inspect your engine’s rough idling issue before moving forward with a repair.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: Low idle after cleaning carb

Firstly, you'll want to verify that you cleaned the throttle body thoroughly since carburetors have not been used for years. The fact that you cleaned the carburetor and disconnected the battery means that the computer will need to relearn the...

Q: 2004 Volvo XC 90 hesitates on highway speeds

To begin with, those cars are notorious for having problems with electronic throttles. So if it has an electronic throttle, I advise to change the whole electronic throttle assembly. I change them all the time on those. Volvos are...

Q: No matter what setting the AC is on it'll only blow out if the defrost vents . I have changed the fuses thinking they may have bee

Hello, thank you for writing in. The climate control utilizes something called "blend doors" to control where the air is being sent through the ducts. These blend doors are controlled by servomotors that open and shut them. Something has likely...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...