On my 97 Accord 2.2L it's slightly knocking after it warms up and it's very consistant. It does it in park and while driving. At first I thought it was pinging, but it's knocking. I was doing very close listening with the hood open and I'm 100% sure it's coming from the engine. Also at times it sounds like the engine is out of balance and the car kinda shakes when I'm cruising at 2500 rpm. I know it's an old engine and it's not 100%. Why does it not knock on cold start and why is it doing this and how can I fix it? I was reading about some other Hondas that have this same problem but I wasn't able to find a answer or solution. Thanks.

 

Clean the EGR ports on the intake manifold.

Watch this video on how to clean. Even though the valve cover was already removed in this video, you don't need to remove it to access the ports.

https://www.youtube.com/watch?v=d8N-SE047VY

 

Harbor Freight sells a mechanic's stethoscope for ~ $10 that works well for located noise sources in engine.
Probably other places sell same, too. In a pince a very long handled screwdriver held to the ear will work.

 

Thanks. I was planning on decarboning this engine sometime soon. Do you think it will clean out those ports as well as other things when I do that? That way I wont have to take anything apart.


Also, so you don't think my engine is going out? I was thinking if it was my engine going out it would just knock all the time.


Also, do you think this sound it's making (if egr port related) is causing damage?

 

The rpm range you are describing is the right range for the EGR to cause a misfire/pinging, so definitely start with those ports.

I do not advise decarboning. It will not clear the EGR ports. You have to remove that cover to clear the ports.

I would advise clearing the EGR ports sooner rather than later. You may want to unplug the EGR solenoid (not the valve) to disable the EGR system. Then listen if the noise goes away.

 

where is the egr solenoid?

 

It is in the engine bay near the driver's fender close to the top and is easy to access. Google 97 accord EGR solenoid to see a picture. The bottom of the solenoid/vacuum control is green plastic.