Hi guys,
I'm new to the forum and very happy to meet you all. I have a problem that I hope you guys can help.

My 05 tsx with 105k miles is having an idle problem. When I put the car in D or R and at stop, there's a rattling noise coming from the engine. I notice that when the car is cold, the noise does not appear. It just appears after driving for a little bit. I also notice that when the car is cold, the idle rpm is around 800 while when it's hot it's only 550-600. The noise gets more noticeable when I turn on the Ac.

I took the car to the mechanic and he said the noise is coming from the oil pan. I took it to acura dealer and they said it's the timing chain. However, I highly doubt it since the noise disappear whenever I give it just a little gas. The car drives and feel awesome otherwise, the noise just drives me crazy.

So far I have tried cleaning the TB, changed all sparkplug, changed the belt tensioner and the noise is still there.

I wonder if there's anything I can do to raise the idle rpm to around 750 so that the noise could go away.

Any input is greatly appreciated!!

Here's the link to the video. Sorry for the 240p quality... I recorded it 720p but idk why youtube reduced it. I included two videos: one when the car is at park/ neutral - sounds pretty normal and one when it's at D or R: rattles and engine vibrates.

 

Does the rattling noise go away when you put the car in park or neutral?

 

Yes. The noise disappears when I put it in Park or neutral. It also goes away when I give it even just a little bit of gas pedal.

 

Once had an Acura 2.5TL that had a similar noise when warmed at idle. It was a cracked exhaust manifold. Crack opened when warmed and closed when cold.

An idle of 550-600 is too low. It should be nearer 700-800. You should get a code if idle was as low as 550-600 rpm. Any check engine light?

Noise seems very loud. Is that the case?

It does sound like timing chain hitting the timing belt cover. Perhaps faulty chain tensioner is not tensioning enough at low idle rpm. Have you tried tracing the location of the noise w/ long screwdriver as stethoscope.

good luck

 

Thanks for your reply. I plugged in the code reader and none came up whatsoever. The noise is indeed pretty low. My mechanic and I traced the noise and it's most audible from the oil pan under the car. Is there any way I can check the chain tensioner without popping the engine open?

 

When my 2004 is hot it idles at 500-600... seems normal to me. Am I the only one?

 

Does yours make the similar noise? It's very quiet at Park and neutral but very loud when at D and R

 

From the FSM, inspecting chain tension requires an extensive disassembly, pretty similar to chain replacement. If going to that much work, might as well replace chain. Shame there's not a way to assess chain slack more simply.

See following video to compare your noise w/ confirmed loose chain noise.


Following video may also be helpful. Worth a try as it's easy to do.


good luck

 

No, I have a manual but no my engine is actually very quiet. I have an exhaust leak but that isn't the engine's fault

 

Is the AC on? Our AC clutches/ compressors can be pretty noisy.
In the summer with the engine cold or warm and with AC on, my idle drops in P and N and goes from 500 to 750 rpms but in D or R it steadies around 800.

 

Know it's been awhile since the post, I'm having the exact same symptoms and also suspect the tensioner as I see it bounce when the rattle occurs. Also used the long screwdriver trick to confirm greatest amplification from the tensioner.

Did you resolve your issue, and if yes what fixed it?