Q: My engine is vibrating and making a knocking sound at idle, which grows intensely when I accelerate but it all goes away at times

asked by on October 17, 2016

The car (lancer evolution X) was in my garage for almost a year. I had just changed my gear box (SST) serviced it and changed my tires. Everytime I turn on the car the entire thing vibrates violently with some knocking and even worse when at high acceleration/speed 75mph. However, there are times when I push the car drive fast or it all goes away for that entire day and the car feels as good as new. The next day the same thing happens. I found some oil stains on the engine and gearbox but engine and gearbox oil level are fine. There is barely any power loss gear shift is good no engine signs at all. No smokes from the exhaust and the oil cover is clean. Coolant liquid is thick green though as apposed to clear green? Coolant level and signs are also fine.

My car has 58000 miles.
My car has an automatic transmission.

This seems to be a torque converter issue. The bolts are probably loose between the converter and the flex plate. To get to the torque converter bolts, you will need to remove the starter from the engine and then you can access the converter bolts. Sometimes the flex plate could be cracked, making the same sounds and vibrations. The other thing that could cause an engine vibration that goes away at times is a loose heat shield on the exhaust system. Check the heat shield for any looseness and tighten it if necessary. If you need assistance, seek out a professional, such as one from YourMechanic, who can help you track down the source of the vibration in your vehicle.

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

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

Knocking while idling.

The description you have given is rather vague, but it could be that what you are hearing is timing chain noise. This engine is well known for having timing chain issues. In fact, Chrysler even issued a recall for this...

Car running fast after warmup.

Having your car run fast like this sounds like a frustrating experience. Let us get you pointed in the right direction so you can drive your car worry-free. The symptom you are experiencing with your vehicle sounds like something called...

Warning lights coming on and car bogging down.

Your 2009 CC has a number of issues that come up often. When the Service Engine light comes on this will also turn on the EPC light as the computer cannot control the electronic power control (EPC) system. A computer...

Related articles

A Buyer’s Guide to the 2012 Mitsubishi Eclipse Spyder
In In 2012 Mitsubishi says sayonara to the 22-year run of the sporty little Eclipse, and with it, the Spyder convertible. This sleek, stylish soft-top has enjoyed many years of popularity as a fairly affordable option for those with a...
How to Get Mitsubishi Dealership Certified
Mitsubishi dealerships offer automotive technician jobs to mechanics who are ASE certified or have completed the UTI Automotive Technology program.
The Best Used Cars to Buy If You Have a Tiny Parking Space
In In many cities parking spaces come at a premium, so you only want to purchase one small space. This small space will end up dictating what vehicle you purchase, so we’ve rounded up some great candidates. Must-haves Arm yourself...