Skip the auto shop - Our mechanics make house calls

Q: My car is having starting issues - 2002 Hyundai Sonata

asked by on

Figured I would give this a shot. I drive my car a lot and it's not in all time best condition. But, since it has been getting colder out when I first start my car it starts but the rpms drop and it turns off. ill try to give it a little power but if I give too much I get a knocking sound from the engine. Eventually I'll get it I t up enough that it stays on but usually when I first go to drive I press a little harder because it doesn't want to go. Hoping somebody can give me an explanation on what to do before I put it back in the shop! Thank you in advance!

My car has 255460 miles.
My car has an automatic transmission.

A: Hi there. From the description you have pro...

Hi there. From the description you have provided, your vehicle’s start and stall may be more serious due to the knock you hear. Assuming the engine does not have a mechanical problem (e.g., collapsed or worn piston skirt, connecting rod bearing failing, oil pressure loss), it could be the fuel pump failing to produce enough pressure when cold.

Low fuel pressure could produce a knock if detonation is occurring from a lean condition. A fuel pressure test when cold could prove the fault. A bad or dirty idle air control valve could cause the stall but not the knock. I recommend having your vehicle’s [starting and turning off](https://www.yourmechanic.com/services/car-starts-and-then-dies-inspection diagnosed and repaired by a certified technician, such as one from 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

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: There is an awful clunking rattling noise when the engine is running.

Hi there. There could be either the engine is having a bearing slap on the rod bearings with too much wear causing the noise or an accessory on the engine is locking up making the belt tensioner pop back and...

Q: I did my brakes on my santa fe all except the rear passenger rotor. this morning the e brake on the rear passenger side locked up

The cable that you are referring to is made of ordinary steel and thus is subject to a lot of rust and corrosion. If rusted, it is possible that the cable is simply failing to retract in the cable sheath,...

Q: running rough, blowing blue smoke then white smoke

Testing and diagnosing will give a technician a good idea of what to expect will be found with internal engine problems, but you can never be totally sure until some disassembly and inspection has been done. Test results leading to...

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...
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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...