Q: Cylinders misfire after using motor flush and oil change - possible sludge issue?

asked by on

I was due for an oil change, so beforehand I used Motor Medic Motor Flush in the crankcase and let the car idle for 5 minutes. During this time, the engine sounded great. The longer it ran, the lower the RPM would get while idling and the better the engine sounded. I drained the oil & motor flush then proceeded with a normal oil change. I also added a can of engine restorer in the crankcase with the new oil. When I first turned the car over after the oil change, it sounded great. Then after the car ran for about a minute, the car started shaking more and more and the RPM got a little wonky. Going up and down 200 RPM each way while idling. I shut the engine off immediately and haven't turned it on since. I took it to the shop and they found that all 4 cylinders are misfiring. I think the motor flush knocked some deposits and buildup loose and that is what's causing the issue with the cylinders, but I'm not a mechanic. What would be the best (cheapest) course of action next?

This is a 2001 Toyota Corolla. My car has 148000 miles.
My car has an automatic transmission.

Hi There, If there are misfires, there should be a check engine light on, which should have stored specific fault codes. Many times these fault codes will indicate whether the misfire is related to a specific cylinder or if it is a general misfire code. Misfires can happen for many different reasons such as faulty spark plug wires or even an injector not pulsing correctly. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle to determine what may be causing this to happen.

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. Cylinders misfire after using motor flush and oil change - possible sludge issue?

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: What else can i do to diagnose the exact problem of my cars miss fire on the 3rd cylinder?

If electronics and fuel supply have been ruled out, the next possible cause is a mechanical issue. Have a compression test done across all 4 cylinders. If #3 is lower than the other three cylinders, it is possible there is...

Q: Clear coat wearing away right before my eyes

Nothing will beat a good paint job. The condition of your paint is caused by oxidation. Depending on how severely damaged your paint is, there are some things worth trying. My first recommendation is to take it to a good...

Q: I'm looking to buy an 01 cobra but the guy selling it says there is a lifter problem. How serious is this and should I buy?

The lifter is not too much of a problem, but it could be costly to replace if you are having a technician replace it. You can try changing the engine oil and filter and running a oil treatment in the...

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...
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...
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.