NEED HELP!!!

[z28marine]

Ive been having this problem for some time, and im not sure whats causing it, so i need some help before i tear my car apart trying to fix it. Just recently my car has started making a whistling noise that comes and goes. When the my car is first started the whistling starts and is there when i drive. But after driving the sound goes away when the engine drops below 1500 RPM's. once i go above 1500 RPM's though, the whistling noise starts up. I havtn had a loss of performance as far as i can tell. The sound is hard to pin point but best to my knowledge its coming from the area of crankshaft pulley on the disributer. not positive. Could it be the crankshaft making this noise? Since the noise goes away after dropping below 1500rpm? I dont know...need some help!

[Joe 1320]

Try removing the belt... It could be the tensioner starting to go south. Removing the belt will isolate the accessories and the tensioner, if the noise goes away you've found the culprit.

[Injuneer]

Any chance you have a BBK aftermarket throttle body? They are notorious for having a "whistle".... almost a "blower" sound. And the problem is caused by casting flash in the idle air passages, so it is a noise that is going to be prevalent with the IAC motor in an "open" position, as it might be on cold start, of when the idle is being help up higher on coastdown.

[Black97]

Strange, for about 1 1/2 weeks I had a similar noise coming from my T/A. When I first started it was really loud but I couldn't pin point it, just that it came from the front of the engine. After driving for a while it would quiet down but not completely disapear.

I visited a friend which lives close by and when he heard it he said it came from the belt due to the high humidity. (It was very hot and humid during that period of time).

Now it cooled down and the humidity is lower and the noise (I would call it "chirping") hasn't appeared again.

Coincidence or did something eventually let go and I didn't notice? Runs fine though.

[BAS]

no problems ever here

I've used a 58mm Edelbrock/BBK T.B. and had no
problems.

I now have a 52 mm Edelbrock/BBK T.B. and still have no problems.

Originally posted by Injuneer
Any chance you have a BBK aftermarket throttle body? They are notorious for having a "whistle".... almost a "blower" sound. And the problem is caused by casting flash in the idle air passages, so it is a noise that is going to be prevalent with the IAC motor in an "open" position, as it might be on cold start, of when the idle is being help up higher on coastdown.

[Injuneer]

Re: no problems ever here

Originally posted by BAS
I've used a 58mm Edelbrock/BBK T.B. and had no
problems.

I now have a 52 mm Edelbrock/BBK T.B. and still have no problems.

Thanks for the positive feedback on the BBK. But after following these boards for 5 years, and reading literally tens of thousands of posts as Modrator of several of the largest LT1 Tech forums, I can assure you that the BBK problem is well known and extensively documented.

[KnightFire]

I know I have exactly what Fred mentioned on my 58mm AS&M TB. It doesn't bother me, I actually kinda like it...but he's right on with a few aftermarket TBs having this "issue". I've read about it many, many times.




KnightFire