Hey Scotty,
I have a 2008 Acura TSX 6-Speed Manual 2.4 DOHC VTEC with 127K original miles that makes a clacking noise from the bottom end on cold starts only. It begins about 15 seconds after starting, and lasts for about 20-30 seconds until the car warms up. I believe this might be piston slap but I could be wrong.
Once the car is warmed up the engine is very smooth and quiet. I have owned the car for a year and it has always done this. The car has decent power and does not use any oil at all. Runs very smooth. My question is, will the lifespan of this engine be shortened? How long can I run the car this way before something fails internally in the engine?
Thanks in advance,
Ryan
Could be VTC actuator. Check the oil and post video if possible.
If you are not burning any oil, the odds are that the noise you are hearing could be the bearings on the connecting rods. Record and upload the sound here, or take it to a mechanic for a listen. Are you SURE it's not noise from your valve train?
It seems like bottom end noise. I believe it is piston slap as it goes away once the piston expands when the engine warms up. I made a video the other day, let me know what you think https://youtu.be/EhZRwWK3KPM
Very unusual, to have what sounds like rod knock on a 128k Honda. Did you buy it used/any idea of it's previous maintenance?
You could hook up a digital oil pressure gauge and see if your oil pressure is within spec - it would probably be low if you have a rod bearing problem.
It is most certainly an interesting phenomenon. What’s strange is it doesn’t do it every time. Just occasionally when it’s really cold out. What you hear in the video is the worst it gets. However it only lasts about 20 seconds and goes away and is quiet.
If the temperate is above 38ish degrees it won’t do it all. If I rev it while it’s doing it then the sound goes away. I don’t think it is rod knock. After doing a lot of research it seems like this is very common of the K24 engine. These engines seem to be noisy on a cold start.