Skip the auto shop - Our mechanics make house calls

Q: Muffler is loud and the van jumps when in idle. When it jumps the muffler makes a puffing noise and smells.

asked by on

Loud muffler. Van Jumps forward in idle and RPM goes up. When the van jumps, the muffler puffs simultaneously and smells.

My car has 150000 miles.
My car has an automatic transmission.

A: This may be related to a failing catalytic ...

This may be related to a failing catalytic converter or potentially a dirty or failing idle air control valve. The idle air control valve reads the air intake as it enters the motor and relays this information to the computer which makes adjustments to fuel. When this is not working properly, you may experience an intermittent idle problem as you have experienced. This may also cause a rich fuel condition producing a smell of fuel as well.

To avoid any unnecessary repairs, I would recommend having an expert from YourMechanic come to your location to diagnose the smell and noise firsthand. One the issue has been pinpointed, the mechanic can service the catalytic converter or idle air control valve as necessary. Best of luck.

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

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: Power steering belt breaking

It appears that the power steering pulley has seized as a result of a failed power steering pump on your Ford Windstar. The burning smell is due to the belt rubbing against the non-moving pulley which creates heat and friction....

Q: Starter or electrical problems

Hello, thanks for writing in. If your vehicle will not jump start and is emitting a chemical smell from the vents, then it may be possible that the battery is bad. An old or worn battery, or one where the...

Q: Truck overheats with new thermostat and waterpump

Hi, thanks for writing in. By reading your description of the overheating issues, I'd tend to agree that the radiator fan clutch may be the culprit of your overheating issues. However, one thing to check into is whether there might...

Related articles

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.