Another timing chain auto-tensioner question

[MarmadukeMSB]

I'm starting to hear a click that, from my research here, sounds like the auto-tensioner. The curious thing is that the noise seems to be linked to driving style. I dont mean that the sound gets more pronounced with higher RPM. If I start the car in my garage and drive around town, I can't hear a thing. However, after every autox lap last weekend, it would tick like crazy for several minutes and then would calm down. Maybe this makes perfect sense and I just don't understand how the tensioner works. I just haven't read anything like this on the boards, so I thought I'd see if anyone had any thoughts. I also have another autox this weekend, and am curious it is safe to take the S, despite the ticking after each lap. :confused:

[repiv]

Before you conclude that it's the TCT, you need to listen to it with a stethoscope when the ticking is present. It might be the TCT or it might not. Valves can also make a ticking noise. Both the TCT and valvetrain noise can be dependent upon oil and oil pressure, although the tensioner is also spring loaded.
To make things more difficult, other things in the engine bay can also "tick". You need to localize it before putting in pricey parts.

[MarmadukeMSB]

Thanks repiv. At first I thought it might just be the heat shield flexing as it cooled since the sound was only arising after laps. But, the more I paid attention to it, the more I concluded it was too rythmic. So, I thought valves or TCT. The more I thought (and listened), the more I started to lean towards TCT since it is a very stable, singular tick. Not a clatter that I would associate with valve noise. Anyway, I'll stethoscope it this afternoon after work and see if I can get any more information.

I'm still concerned about taking it to the track this weekend, though. Can you describe the failure mode of the TCT? Do you think it is at risk of serious damage if it is indeed the tick culprit and I autox with it? If it does fail, what does that mean for the rest of the engine?

Thanks for your help,
Mike

[desmo4]

You can eliminate the valve clearance by checking it. I just checked and adjusted them a couple weeks ago as a 100 K present to the car. I found a few loose intake and 1 exhaust valves. This quieted things down a lot.

Jonathan

[MarmadukeMSB]

Thanks Desmo. I've been meaning to check them, too. Just turned 50k mi a month or so ago. Can you get a feeler gauge set at retail stores? I know theyre in my Grainger catalogue, but I'd rather pick them up somewher than order them.

[alvanderp]

You can find feeler gauges from any retail auto parts store or Sears. I like the go/no-go gauges, they make the first inch or so of the gauge the reading you want, and the rest of it .002" thicker, so it physically stops on that edge when you insert it and the lash is set correctly. Its alot easier than trying to feel the drag of the gauge, especially when trying to get to Cyl #3 and #4 on the S2k....

[repiv]

Can you describe the failure mode of the TCT? Do you think it is at risk of serious damage if it is indeed the tick culprit and I autox with it?
If in doubt, don't risk it. As far as I've seen, no ticking TCT has been the cause of an engine grenading. The ticking is an indication that the tensioner needs to be looked at. A bad one is not generally intermittent like yours. It becomes a steady tick that is more prevalent after a cold start and while oil pressure is low, tending to lessen as revs and oil press rises (but not always).
The fact that yours happens only after an auto-x session introduces another variable.

[MarmadukeMSB]

Thanks guys. Here's a little update. It rained yesterday and was cold, so I decided to take the S knowing I wouldn't be making runs at 100%. I brought a stethoscope with me, so if the ticking returned, I could try and hunt it down. Sure enough, when the sound is present, touching the chain tensioner with the probe gave me the loudest sound. I still don't really understand why the sound is more prevalent after sustained high RPM, but I've got awhile before the next time the S is up on cone duty to think about replacing it.

[repiv]

If you've narrowed it down, then Part 12 in the following is the TCT:

http://www.slhondaparts.com/browse.asp?Model=S2000&Year=2000&TrimLevel=2DR+S2000+&TransLevel=6MTKA&Section=A&Category=E++11++%7CCAMSHAFT%2DCAM+CHAIN&Doors=2&Emissions=KA&PartCatalogId=14S2A0&ViewParts=true

It would be helpful to have the service manual so you know the procedure for changing it.