Q: Engine Knock only during start up and acceluration, some oil found in spark plug well also. possible rod knock

asked by on

2007 Scion Tc Auto, I have a somewhat noticeble knock only during startup( less than 3 seconds during turning over) and during acceluration between 2k-3krpm. During idle it sounds completely normal no abnormal tapping only slight value tapping which is said to be normal in these cars. I notice some oil on my spark plug and in the well of cylinder 1 during tune up other three are dry. Also smokes a bit near the headers near the first value. Could this be sign of possible rod bearing failure, or spark knock? no CEL or oil level lights are on.

My car has 167000 miles.
My car has an automatic transmission.

Hi there:

If you’ve found oil in the spark plug well is a sign of a fairly serious problem that should be inspected and repaired immediately. It is almost always due to a failing gasket or O-ring but can also be the result of a failing piston or worn valve guides. This could be the source of the engine knock and other issues you’re having. It’s probably a good idea to have a professional mechanic complete a oil is leaking into spark plug well inspection, so they can determine what’s causing your issues.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Engine Knock only during start up and acceluration, some oil found in spark plug well also. possible rod knock

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: Q: Car has been sitting for over year, what do I do?

Hi, thanks for writing in. I'd be happy to help. I would suggest checking your tires, fuel condition, changing the oil and air filter, and maybe running some good fuel conditioner through the fuel tank. More than likely, if the...

Q: My speed sensor went bad twice in 10 days

Hello. The problem you're experiencing with your speedometer may be related to the speed sensor cable that attaches from the sensor on the outside of the transmission to the actual speedometer on the car. About 80 percent of the time...

Q: Q: Clicking sound when braking

Hello. A clicking or tapping sound during braking can be caused by a wide variety of issues. It may be possible that the noise is coming from the suspension, steering, or even from the brakes themselves. A few common causes...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
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...