[Redguy1959]

I have a rattling noise that comes from the timing chain area of my 2000 Honda Insight with M/T. It happens most frequently on hot days and happens more often once the engine is fully warmed. The noise stops immediately whenever the engine stops running. It is greatest at startup when hot, but I can also always hear it during acceleration in first gear and second gear but at that point the road noise seems to overtake it. Also when fully warmed, I can hear it at idle and I can make it last quite a few minutes this way until I hold the engine revs up for awhile. It can grow loud and disconcerting and has been happening more often.

The car has 255,000 miles on it. I just replaced the rod bearings, which were hardly worn at all, and this made no difference in the noise. I also replaced the external timing chain tensioner and this made no difference. There are no exhaust leaks and the valves are adjusted properly (and not noisy). I did notice the AC compressor pulley bearing is noisy but this seems to be a distinctly separate noise.

I noticed that the service manual says the engine must be removed to replace the timing chain, and that the engine gets removed from the bottom of the vehicle. I do not have the equipment to accomplish such a feat. I did find it very easy to remove the oil pan and the cylinder head does not look too hard to remove either. I took a look at the clearance between the right side of the engine and fender wall and it looks like there is plenty of space to remove the timing chain cover. Does anyone know why the manual says the engine must be removed to replace the chain?

 

[Willie Williford]

Remove the valve cover as if you are going to adjust the valves and see how high you can pull the chain from the sprocket, at it's highest point.

Almost forgot:
PLEASE post your location in your profile/location.
THANK YOU
Willie

 

[honda-dave]

yeah because even with the engine out the chain is an absolute PITA to time up when installing a new chain.
I would not like to attempt it with the engine in
There are internal chain guides that wear as they are plastic coated maybe try replacing those 1st, the chains are mainly bullet proof IMHO hence the chain guides usually wear out 1st rather than the chain stretch or wear.

 

[parbuster54]

Timing Chain noise.

Post a video of the sound. I have a metallic chirping sound in my engine. Look at my post below your post and listen to mine. Does it sound anything like this?

 

[Redguy1959]

Thanks everyone for pitching in. I have updated my profile with location Aberdeen, NJ, US. It's been about 86F so far this week during the day.

I will let you know about the chain slack with the valve cover off. As for the plastic chain guides, can these be replaced without pulling the engine out? I guess what I am really asking is there anything that prevents access to the timing chain and guides when leaving the engine in. I can picture some lone bolt that won't clear or the timing chain cover not clearing the end of the crank, but it really doesn't look that way. Don't want to go through a lot of work and then be surprised in this manner.

Just an update, the sound became loud enough this evening that I turned the car around and parked it, taking another vehicle instead. It is a definite buzzing/rattling noise at idle and it seems to be lasting longer before quieting down. When it is happening I can "feel" the sound by touching the engine cover.

I did watch parbuster54's "metallic chirping sound" video. I do not have that sound. The sound I have is similar to the rattling sound I can hear in the background of the video, but mine is much louder.

 

[samwichse]

Err, maybe it's just a wrecked idler/tensioner pulley?

A lot cheaper than timing chain anything and easy to check.

Sam

 

[Willie Williford]

Like Sam says, disconnect the serpentine belt and see if the noise goes away. Don't run the engine too long, maybe start with a cold engine.

HTH
Willie

 

[Redguy1959]

Here is an update. I knew the air conditioner pulley bearing was noisy and I replaced that yesterday. That removed 80-90% of the noise. In particular, it eliminated regular bearing noise, but also the rattling at idle which sounded so much like a timing chain appears to be gone.

The one noise that remains is the rattling sound when accelearting in 1st gear (loud) and 2nd gear (audible) which also sounds like a timing chain. The noise only happens under load - the engine is pleasingly quiet when idling and when revving. So now I'm thinking maybe it is something in the drive train and not the engine. It is definitely coming from the front engine area and to the right.

I will still pull the valve cover off and check timing chain slack as well as see what I can see on the guides. Will also make a recording of the sound and post it soon.

 

[Jivko57]

The remaining noise is probably the input shaft bearing in the gear box. Lots of info in other posts. It is one of the weakest spots on the insight 1.

If it is the bearing , the sooner you fix it , the better as with time it will create more problems in the transmission.

 

[biododge1]

checking wont hurt, but id be shocked if it was your chain or guides. My cam got twisted and the chain/guides never even noticed it! They look like new. If there is slack, make sure the tensioner is working, and the filter isn't clogged (it has a screen filter). By working I mean the little piston moves in/out easy on the tensioner.

 

[Redguy1959]

Thanks folks. The timing chain tensioner and screen are new. I have been reading about the tranny input shaft bearing and it seems to match the symptoms about hearing it in first and second gear while accelerating. People are saying the tranny is not too hard to take out. I have a couple of questions as I don't have the service manual here with me right now, so these may be simple questions: 1) does the tranny come out from the top or bottom, and if the bottom, how much clerance between the vehicle and floor is necessary? I am asking because I don't have access to a lift, only jacks, plywood and dirt. I was able to easily pull the oil pan using drive-up ramps for clearance, hoping the tranny does not require much more space.

 

[Redguy1959]

I made a video with the knocking sound I am hearing. You will probably need to crank the volume up to hear. It's not anything you can make happen when sitting still.

 

[Willie Williford]

Sounds like ISB to me.