Skip the auto shop - Our mechanics make house calls

Q: Truck is missing only when it is in gear

asked by on

A couple weeks ago my truck started randomly missing while driving then gradually got worse till it was constantly missing but only while in gear.It runs fine while in park.I replaced plugs,wires,and coil packs about a year ago.Yesterday I changed the fuel filter,cleaned the MAF sensor and checked all vacuum lines for a leak and it is still doing the same thing.The check engine light is not on or flashing and it isn't throwing any codes on a scanner.What am I missing here?I don't understand what else could cause it to do this.

My car has 161000 miles.
My car has an automatic transmission.

A: Hi there, thanks for writing in. If this p...

Hi there, thanks for writing in.

If this problem only happens when you're in gear and accelerating, its very possible that it could have a transmission problem that causing a hesitation. I have seen issues like this before. It's also very possible for the MAF sensor to cause a rough running condition without throwing a fault, or it could have a clogged fuel filter causing low fuel pressure. A clogged or sticking injector wouldn't set a fault, but can cause a rough running condition as well. There could be a problem with a knock sensor or with the ignition timing. The best place to start would be checking if it's a transmission problem or an engine problem. If it ends up being an engine problem, start by checking the fuel pressure and ignition timing. If you want to have this issue professionally diagnosed, you can contact a qualified independent technician through YourMechanic.

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: New starter doesn't start car.

I would have the battery load tested to see if the battery is good then have a technician diagnose the electrical system. There are a number of electrical parts on the car that could be bad.

Q: Over heating cracking radiator

My guess is that you have a combustion leak from a blown head gasket, cracked head or cracked block. A combustion leak will result in excessive cooling system pressure, which could in turn lead to a cracked radiator. A professional...

Q: Compatible anti theft system to replace

The only system that would be compatible would be another 1999 Cadillac Eldorado and this would not work since it would only be programmed to work for that vehicle. You would need new parts from the dealer and have it...

Related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.