Guys,

I just got an '89 TII with 43,000 miles on it. It is in mint condition (check it out at http://members.***.net/toddkageals). It has a humming/buzzing sort of sound coming from the engine compartment that changes with engine RPM. It does not change with throttle/speed, only RPM. Sounds like a very quiet version of the over-rev buzzer that changes with speed (if that makes sense). The car runs perfect but I didn't notice this noise until today, not sure if it just started or what (it was very cold here today). Also.....any negative effects from just unplugging the electrical connector on the AWS? As far as I know, all it does is cause a very cold engine to race above 3000 RPM.

Todd

 

Congrats on the car. Wish I could help, haven't a clue. Still, nice car!!

 

is the hum only present on start up? does it disappear (or quiet down) as the idle calms down to the 750 after the car is warmed up?

 

I have that on my '89TII, couldn't tell you what it is though. When I bought the car new it didn't have that sound, but at 8,000 miles, because of a problem, the dealership changed the ecu. Ever since the change I've had it. Doesn't seem to affect anything being it's been doing it for 12 years. Even does it with the new engine installed in August.

 

It does seem to quiet down after a while but it does not go away. Glad to hear it does not affect anything. I'll let you know if I find out what it is. I might try removing the belts one at a time to see if I can isolate it. What about the ABS valve? OK to just unplug it?

Todd

 

the hmm is most likly an alternator / electric / grounding problem.

does it come through the speakers or from the engine bay?

you can unplug the AWS no prob. the ECU will store a code but the engine light won't come on.

 

maybe check the tension on the belts?

 

Unless they changed it for 89+, just start the car with the stick in gear. This will bypass the AWS.

My vote for the buzz - electrical, check your alternator.

Henrik
87TII

 

Take a chunk of garden hose or any hose of that type, put one end to your ear, and the other end to somethingon the engine. Use it as a stethescope to locate the origin of the sound.

 

Shot into the dark...

Make sure that there are no cables or connectors riding on any of the belts or pullies. I had on of the clips for the throttle cable break near the alt. (the pass side of the alt...drivers side has that metal clip). The cable dropped and came into contact with the alt. pulley and was making a whirring noise that changed via rpm of course ...

 

Hmmmm....could be something like that. I'll check it out. The buzz was gone this morning but I was not running the headlights/heater, etc.....maybe that indicates alternator. I'll test that this afternoon. Yeah....starting in gear disabled AWS, thands for the tip. Car started and dropped immediately to 1700 RPM idle (very cold this AM)...much better than racing up to 3000+.

Todd