Beep13

Hello, I recently had the timing chain go in the GF's 2010 TSX. I caught it just as it happened. Had the head resurfaced, replaced the timing chain, all guides, tensioner, lapped the valves. Car has been running great for a few hundred miles. Now I am getting a rattle when i first put the car into gear, its AT, but as soon as I start moving it goes away. Doesn't happen in neutral either. It sound like its coming from the belt side, but can't put my finger on it. I replaced the belt tensioner, it seemed like it had a slight wobble. That did not fix it. I found a clip of the exact sound, any ideas?

Beep13

Added my own video:

altair47

Remove the serpentine belt and start without it, if the sound remains, then I think with a probability of 85% you need a valve adjustment.

Beep13

Hello,

Thanks for the response.
I am definitely going to try without the belt, to rule out all clutch/pulleys.
That should at least isolate if its engine related or not.
Just out of curiosity though, what leads you to believe its the valves?

Thanks!

Acura tech

This is a normal service procedure, nothing else in these engines can make such a noise. In the former USSR, due to the poor quality of gasoline, Honda makes it mandatory to do this procedure every 40,000 km (25,000 miles).

altair47

Yes, I think he's right, there's nothing else to make that noise.

Beep13

Which procedure exactly? I just redid the valves, highly confident this isn't valve related, what procedure are you referencing?

Beep13

So i took off the serpentine belt, started the car, put in gear, no noise. Tried a few times. Put the belt back on, start the car, put into drive. noise is back. So it has to be belt/pulley related. Its a brand new belt and tensioner, unless i got a defective one... I checked all pulleys, none of them have play, also there is no visible wobble. Any other ideas? I put a screwdriver up to each component and listened (redneck stethoscope) but couldn't isolate the sound.

altair47

He means valve adjustment. If you have adjusted the valves, and this knock is not from the valves, then you need to take a statoscope and localize the place of the knock (head, timing mechanism or short block).

Beep13

If it doesn't happen with the belt off, doesn't that rule out head and block, I really don't think this is engine related...Has to be belt/pulley, imo.

thinking it may be the a/c clutch starting to go. I thought that yesterday, but it turning on/off a/c didn't seem to make much difference, maybe the clutch is just starting to lock up here and there, going to try it.

altair47

I wrote to you at the very beginning to rule out attachments, you need to remove the belt, here you are, you removed the belt and found out that the problem is not in the engine, congratulations.

Beep13

correct, i mentioned yesterday i was going to try removing the belt, just hadn't gotten to it yet. Was just asking for a explanation of why you automatically pin pointed the valves? I put in the original description that i just redid the valves. So was curious why you then immediately suggested it was valves? Also maybe my video wasn't clear, but it honestly sounds nothing like valve noise, imo. I was really just looking for an explanation of why you automatically suspected valves... Also we are all on here trying to help each other correct? and to learn a thing or two

altair47

Seeing how incompetent people are now repairing cars, I immediately assumed that the mechanics had done something wrong. Buy a stethoscope you will not have problems with the localization of noise

Beep13

Ok yeah I get it. But I had the valves redone by a reputable machine shop. I also lapped them myself, and I do know what I'm doing. The noise is 100% not coming from the valves. The engine runs and sounds great (under normal conditions). I didn't feel comfortable climbing underneath, since it has to be in gear, and I don't have a lift. Also I'm running out of time as I am packed up and moving. I took it to the local shop. They thought it was the belt tensioner as did I, but then realized it wasn't. They also put some pressure on the engine while it was on the lift, just to rule out any motor mounts ectd. They also confirmed that this only happens at low idle when the engine is under load. Their consensus was that the sound is coming from the oil pan. I've heard of the chain tensioner for the oil pump going (has some fancy name), and the plastic piece rattling around in the oil pan, but they said the sound was too loud to be that. They said the engine sound greats under normal conditions, timing and valves sound good, the car drives great, and they could only reproduce the sound at low idle with some load. They are convinced its somewhere in the bottom end but sadly they don't do that kind of engine work there, so I have to get the car back. I'm debating if its even worth dropping the oil pan just to check the lower chain tensioner. My only other fear is if its a crank bearing that is starting to go, maybe its just the low rpm thats causing it to start rattling? I dunno...any other ideas?