Strange intermittent whining noise at 70-80+ mph - Honda Prelude Forum

KahnBB6 · 07-16-2007, 10:08 PM

Hey guys,

I've tried searching for transmission noise threads and threads related to timing belt and autotensioner issues, but none of those symptoms *quite* describe what I'm experiencing.

During normal city driving, the car is fine and exhibits no issues, strange noises or idle problems. At highway speeds anywhere between 70mph and very often 75-85mph, there is a strange intermittent whining noise coming from somewhere in the front of the car. I've thought it might be wheel bearings or something related to axle seals but those are just blind guesses.

What's important to note is that the car does not make this whining noise below 75mph. Very seldom, it appears at 70mph but nowhere lower than that.

The car has a new ACT Stage II organic clutch with a new 8lb Fizanda aluminum flywheel, both very recently installed. The front brakes and rotors where also replaced just this last week. This did not cure the strange sound.

Has anyone had something like this on their 5th gen SH?

gtprelude · 07-17-2007, 06:12 PM

Yep. Been there since I got it. I figured it was an auto trans thing. I am almost 100% sure mine is coming from the transmission. It has done it for 60000 miles so I am not worried. Just a little bothersome.

KahnBB6 · 07-22-2007, 11:48 AM

This car is a manual transmission model.

I've reread some of these "strange noise" threads and I've got a hunch it's in the timing belt area. Maybe something to do with the auto-tensioner wearing out and/or the timing belt rubbing against the valve cover. The car does make a "shhrrrr" noise sometimes when I'm at about 4000 RPM and I let off the gas. The only thing I don't understand is that it only does this at about 75 MPH and higher. The symptom is related to a mostly predictable vehicle speed in 4th or 5th gear instead of just a predictable RPM.

pter · 07-24-2007, 11:11 AM

Put it in neutral and rev it and hold it ~5k rpms. Do you still hear it?
I had that noise with my car when I had a lightened flywheel put in. Very high pitch whining noise, only at high rpm.

KahnBB6 · 07-24-2007, 01:43 PM

pter,

My mechanic suggested this yesterday and I tried it. The whining noise did not go away while coasting around 90mph in neutral, with both holding at 4000rpm and dropping to idle. Turning the steering wheel left or right while doing this had very little effect on the noise. Slowing down to at least 70mph made it go away.

I'm relieved to know it's not an engine timing belt issue (although I'm due for that in 20k miles anyway).

I have only a few guesses at this point.

--tie rod rubbing
--brake rotors, pads, or shims rubbing (the noise was present before the brakes were serviced two weeks ago)
--wheel bearing failure
--tire/rim balance
--front axle(s)
--front axle seal, grommet, etc.
--something connecting to the ATTS unit with a bad seal, etc.

The ATTS and transmission fluids were changed around 105k.

kellyk75 · 07-24-2007, 02:41 PM

Judging by the thread title..... it might be your girl friend. I would suggest trading in. They are hard to find but you can get ones that make a "yeee haaaaa" noise over 80+ mph.

kellyk75 · 07-24-2007, 02:43 PM

Seriously though, could it be your timing belt?

Edit: oops, missed the one line in your last post.

KahnBB6 · 08-08-2007, 01:51 AM

I took the car in last week to get it checked over. My mechanic ran through the gears on a lift (I don't remember the exact procedure, sorry) and he seemed to think it was the transmission countershaft. The noise only appeared in 4th and 5th gear.

I'm going to have to wait on it for now.

98auto · 08-08-2007, 02:00 AM

yea, could be a bearing on the countershaft going bad....

KahnBB6 · 08-08-2007, 02:07 AM

Have you had any past experience with countershaft problems? I'm curious of what I may be getting into replacing/repairing.

98auto · 08-08-2007, 01:09 PM

I havent but I have my tranny apart right now...Its gonna be $$$ to fix. Figure the parts are about 100 bucks...the bearings arent cheap, I think they are like 40-50 each. Plus you should change the seals while you are in there. Then you pay for the labor of removing the tranny, then taking it apart, then putting it back together and putting it back in the car...

KahnBB6 · 08-08-2007, 01:23 PM

Well the labor cost is a given. Bearings and seals only would be nice at around $100. I guess I'm more concerned about having to replace more expensive parts. I don't have any 5th gear grinding (yet) and otherwise the transmission is fine. From what I understand, this whining noise can be caused by the tolerance between the gear teeth being either too loose or too tight on the countershaft. This suggests eventual gear damage to me if left unrepaired.

98auto · 08-08-2007, 08:58 PM

true...its hard to say what it is for sure without opening it up...I think a brand new honda tranny is around 1800? or 2K?

KahnBB6 · 08-13-2007, 08:43 PM

I am not sure how much a whole transmission costs but I wouldn't put it any less than $1200.

Looking up the countershaft as an OEM part, they run about $320 list from Honda. I wish I knew more about assembling transmissions. Tools and ample workspace would be nice, too.

I'm going to see if I can drop the car off tomorrow and get myself a rental. While I'm at it, I may get one of those Blackstone engine oil analyses done. I haven't read up on how to but now is as good a time as ever when I'm looking at transmission work already.

KahnBB6 · 08-25-2007, 10:51 PM

Update:

Car went in for repair last Monday. It's definitely countershaft bearings gone bad although my mechanic says they don't look worn out. Gears are fine 1-5 and reverse. I asked him to double check 5th gear since I know it begins to grind after enough miles. I'm also having him replace the synchros on all gears while he's got the tranny apart.

Too many things to fix/service on this car and not enough time in between to upgrade it. I wouldn't mind so much if it went like an FD RX-7.

Update 8/29/2007: He finally identified the worn bearing that was causing this issue. It was only on one side of the countershaft. Found no issue with 5th or with any any synchros, so they will be left alone.

The car should be back on the road next Monday.