Timing chain tensioner or valve relash issues?
06-17-2009, 07:33 AM
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Timing chain tensioner or valve relash issues?
Posted this in UTH but wanted to get some local opinions as well:
2 weeks ago, I adjusted my valves - and torqued the nuts to 18lbs as per the manual. Attended an autocross the very next day and beat on my car. This past Sunday, I headed to the track and I beat on it again.
As I head home, a new noise developed; a very distinctive "tick" sound coming from the engine bay. I have never heard of the infamous TCT problem until now, and that seems like the most likely culprit.
However, there's a definite 'miss' at idle, and from the youtube videos in Billman's thread here: https://www.s2ki.com/forums/index.ph...&f=22&t=468984 it seems like my 'tick' is a much slower pace. No one describes of a 'miss' at idle as either.
Is it possible that the nut on the valve backed out, and if so what damage could have occured? I tried using a poor-man's stethescope (screwdriver handle to ear) but I have been unable to localize the tick. I'll be checking the valves ASAP but time constraints haven't allowed me to yet.
Are there other ways to diagnose whether it's the TCT or the valves w/o removing the valve cover?
Thanks
2 weeks ago, I adjusted my valves - and torqued the nuts to 18lbs as per the manual. Attended an autocross the very next day and beat on my car. This past Sunday, I headed to the track and I beat on it again.
As I head home, a new noise developed; a very distinctive "tick" sound coming from the engine bay. I have never heard of the infamous TCT problem until now, and that seems like the most likely culprit.
However, there's a definite 'miss' at idle, and from the youtube videos in Billman's thread here: https://www.s2ki.com/forums/index.ph...&f=22&t=468984 it seems like my 'tick' is a much slower pace. No one describes of a 'miss' at idle as either.
Is it possible that the nut on the valve backed out, and if so what damage could have occured? I tried using a poor-man's stethescope (screwdriver handle to ear) but I have been unable to localize the tick. I'll be checking the valves ASAP but time constraints haven't allowed me to yet.
Are there other ways to diagnose whether it's the TCT or the valves w/o removing the valve cover?
Thanks
06-17-2009, 12:42 PM
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Yeah - real loud when cold. In fact, it's worse when cold...it's not fast enough to sound like a diesel. Too slow...it's a very pronounced "tick tick tick" altho very simliar to that of the TCT, just the "ticks" are not as frequent from the videos that I've heard.
06-17-2009, 07:18 PM
#5
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Here's our experience with TCT noise on EgoThreat's car:
- Only when cold
- Only for a couple seconds after startup
- More likely with low oil
- Very rarely after a fresh oil change
I suspect the TCT just requires more oil temperature to operate, so when the oil is thick or low, there's not enough flow to get the pressure to the TCT. And although it's slow to take up the slack, it does eventually after a couple seconds.
I've seen some video of an S2000 with constant TCT noise however. I assume he had a totally frozen up TCT. The above is just what we've personally experienced.
- Only when cold
- Only for a couple seconds after startup
- More likely with low oil
- Very rarely after a fresh oil change
I suspect the TCT just requires more oil temperature to operate, so when the oil is thick or low, there's not enough flow to get the pressure to the TCT. And although it's slow to take up the slack, it does eventually after a couple seconds.
I've seen some video of an S2000 with constant TCT noise however. I assume he had a totally frozen up TCT. The above is just what we've personally experienced.
06-17-2009, 08:08 PM
#6
Originally Posted by Elistan,Jun 17 2009, 09:18 PM
Here's our experience with TCT noise on EgoThreat's car:
- Only when cold
- Only for a couple seconds after startup
- More likely with low oil
- Very rarely after a fresh oil change
I suspect the TCT just requires more oil temperature to operate, so when the oil is thick or low, there's not enough flow to get the pressure to the TCT. And although it's slow to take up the slack, it does eventually after a couple seconds.
I've seen some video of an S2000 with constant TCT noise however. I assume he had a totally frozen up TCT. The above is just what we've personally experienced.
- Only when cold
- Only for a couple seconds after startup
- More likely with low oil
- Very rarely after a fresh oil change
I suspect the TCT just requires more oil temperature to operate, so when the oil is thick or low, there's not enough flow to get the pressure to the TCT. And although it's slow to take up the slack, it does eventually after a couple seconds.
I've seen some video of an S2000 with constant TCT noise however. I assume he had a totally frozen up TCT. The above is just what we've personally experienced.
mine is opposite
anytime the car has been sitting for hours..... no TCT rattle
when the car is hot as hell? car sounds like a diesel at idle
06-17-2009, 08:36 PM
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Yeah from all the different videos it seems to come in all different shapes and forms. My kicker is that my idle was missing -- not sure why that is. But I pulled my ignition pack and it looks like one of them was wet - so the valve cover gasket needs replacing. That could explain the miss. I really thought a rocker nut had backed out! 
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06-18-2009, 08:11 AM
#9
I had the TCT issue with my S as well, or at least the sound. However, it was across the board in terms of when it occurred (hot or cold, easy or hard driving, and no consistency). I had the TCT replaced 3 times under warranty and finally just let it go until it got constant.
I took it to Jotech (they are just down the road from me) and they couldn't find a cause, tensioner was working, chain was OK, etc. I had an old cover and brought that in so we could see if maybe the replacement was from a newer model, but the part # was identical and they looked identical as well.
However, I did notice a very (very) slight "wear" mark on a support strut (for lack of the proper term) of the new one. Couldn't say for sure it was a wear mark it was so light, but when Kenny saw that and looked closer at the chain it seemed like one side might be lighter than the other (ie, indicating wear). All very minor... but we agreed that it seemed reasonable to shave that strut down a few millimeters and see what happened.
Fixed! No more TCT noises! (I did go ahead and replace the tensioner and chain at that point, because why take chances.)
We think that my issue was related to replacing the original cover; while it was the same part #, it only needed to be different by 2mm to cause occasional contact as that support is right next to the chain.
I took it to Jotech (they are just down the road from me) and they couldn't find a cause, tensioner was working, chain was OK, etc. I had an old cover and brought that in so we could see if maybe the replacement was from a newer model, but the part # was identical and they looked identical as well.
However, I did notice a very (very) slight "wear" mark on a support strut (for lack of the proper term) of the new one. Couldn't say for sure it was a wear mark it was so light, but when Kenny saw that and looked closer at the chain it seemed like one side might be lighter than the other (ie, indicating wear). All very minor... but we agreed that it seemed reasonable to shave that strut down a few millimeters and see what happened.
Fixed! No more TCT noises! (I did go ahead and replace the tensioner and chain at that point, because why take chances.)
We think that my issue was related to replacing the original cover; while it was the same part #, it only needed to be different by 2mm to cause occasional contact as that support is right next to the chain.
06-18-2009, 08:14 AM
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Originally Posted by turbolane,Jun 18 2009, 11:11 AM
I had the TCT issue with my S as well, or at least the sound. However, it was across the board in terms of when it occurred (hot or cold, easy or hard driving, and no consistency). I had the TCT replaced 3 times under warranty and finally just let it go until it got constant.
I took it to Jotech (they are just down the road from me) and they couldn't find a cause, tensioner was working, chain was OK, etc. I had an old cover and brought that in so we could see if maybe the replacement was from a newer model, but the part # was identical and they looked identical as well.
However, I did notice a very (very) slight "wear" mark on a support strut (for lack of the proper term) of the new one. Couldn't say for sure it was a wear mark it was so light, but when Kenny saw that and looked closer at the chain it seemed like one side might be lighter than the other (ie, indicating wear). All very minor... but we agreed that it seemed reasonable to shave that strut down a few millimeters and see what happened.
Fixed! No more TCT noises! (I did go ahead and replace the tensioner and chain at that point, because why take chances.)
We think that my issue was related to replacing the original cover; while it was the same part #, it only needed to be different by 2mm to cause occasional contact as that support is right next to the chain.
I took it to Jotech (they are just down the road from me) and they couldn't find a cause, tensioner was working, chain was OK, etc. I had an old cover and brought that in so we could see if maybe the replacement was from a newer model, but the part # was identical and they looked identical as well.
However, I did notice a very (very) slight "wear" mark on a support strut (for lack of the proper term) of the new one. Couldn't say for sure it was a wear mark it was so light, but when Kenny saw that and looked closer at the chain it seemed like one side might be lighter than the other (ie, indicating wear). All very minor... but we agreed that it seemed reasonable to shave that strut down a few millimeters and see what happened.
Fixed! No more TCT noises! (I did go ahead and replace the tensioner and chain at that point, because why take chances.)
We think that my issue was related to replacing the original cover; while it was the same part #, it only needed to be different by 2mm to cause occasional contact as that support is right next to the chain.