My 1998 2x4 2.4 cylinder tacoma truck (69k miles) is making a noise when idling or in any of the gears (5 spd) going down the road. The noise goes away when I barely touch/depress the clutch (depress about 1/2 to 1 inch). Any ideas what is making this sound? It’s not a growl or rattle, but a very high pitch, whistling sound almost like a cross between a cricket, cicada and grass hopper.
I think it is very likely that the clutch throw-out bearing needs to be replaced. This is a case where the part is relatively cheap (probably less than $50), and the labor is fairly expensive (~$600??).
If the clutch on this truck is the original one–which is likely with only 69k on the odometer–I would suggest having the clutch replaced at the same time. The labor that is involved with just replacing the throw-out bearing is essentially the same as the labor for doing a full clutch job, so it would be economically in your best interests to just go ahead and replace the clutch now along with the throw-out bearing, rather than potentially paying the same labor charges again in a year or two when the clutch wears out.
However–It is remotely possible that the problem is just the result of a bad clutch slave cylinder, so have this possibility checked before dropping the trans and doing any major internal clutch work. If the slave cylinder is bad, you should probably just go ahead and replace the clutch master cylinder at the same time, as they tend to wear at a similar rate.
I have had a couple people offer opinions on the issue and one person thinks it might be in the early stages and rather than the throw-out bearing being bad, it might be partially manipulated by the amount of free play in the clutch. Could a clutch adjustment allow for this thing to spin freely rather than impeded? Also, a neighbor/mechanic who knows most everything thinks it might be a bearing in the transmission and that this could be dealt with with a flush and refill with synthetic fluid. Any thoughts on that? Again, the sound just doesn’t seem loud enough to be the throw-out bearing. It is barely audible, but just annoying enough. In fact, one neighbor can’t hear it because he doesn’t hear that part of the sound spectrum…too high pitched.