odd sound
Thread Starter
Racer
Joined: Apr 2006
Posts: 300
Likes: 0
From: Joplin Missouri
odd sound
I finally got the 74 bb running. Now when I turn it off there is a whinning noise that sounds like a turbo. Does anyone have any thoughts? Something is spinning somewhere just dont know where. Is this normal? There is no mechanical fan so I know its not that. Could it be my torque convertor or is my starter still engaged? Its a 74 and I do have a jump wire to fool the seatbelt sensor.
Thanks
Graham
Thanks
Graham
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
check immediatly and makeure it isnt the starter still engaged.Those things overheat,catch fire and can burn your car to the ground.I lost a very nice 66,Impala,396 that way.Its now shoved somewhere on the bank of the Little Big Horn river, acting as errosion control.
Thread Starter
Racer
Joined: Apr 2006
Posts: 300
Likes: 0
From: Joplin Missouri
Thanks what I am thinking it is. It was a bit warm. Do I need a new one? Or is it because I have the jumper wire connected to the purple wire. (seatbelt interlock switch). It hard to get under there cause of the sidepipes to double check. But it does sound right.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
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From: New Hill NC
Thread Starter
Racer
Joined: Apr 2006
Posts: 300
Likes: 0
From: Joplin Missouri
From what I understand about my starter is there are 3 terminals. The battery, a red wire and a purple wire. In 74 GM thought it would be a good idea to install a seatbelt interlock system. So if the seatbelts arent buckeled no power would go to the purple wire. So after doing some research here I found out that if you have a wire going from on therminal to another one on the SIS you can fool the sensor to thinking all is well. It works great it starts. but I wonder since I did this I now have constant power going to this terminal. Maybe the starter doesnt know to turn off. I dont know if the sound is present durring operation the car is loud. Just my 2 cents though.
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Pro
Joined: Feb 2006
Posts: 718
Likes: 7
From: Jacksonville , NC
If the starter is spinning but not engaging with 12V, that is definitly something that needs to be addressed. I know from experience that the starter will spin but not engage if the battery and purple wire posts are jumped and the post for the purple wire is not secure. Check to see if the post that the purple wire is attached is secure to the solenoid. (you can have the wire tight but the post not secure). Wiggle the post to check. Is the noise present when you turn the key "on" but not "start"?
Thread Starter
Racer
Joined: Apr 2006
Posts: 300
Likes: 0
From: Joplin Missouri
It starts beautifully. I hear the sound for a few seconds after everything is shut down. It is a spinning sound like with a turbo or fan. It that sound you hear after a 747 powers down. Could it be my stall convertor? I put a 3200 TCI on. I just cant think what else could be spinning that fast to produce that sound.
Thread Starter
Racer
Joined: Apr 2006
Posts: 300
Likes: 0
From: Joplin Missouri
No I dont have anyof those things on. Maybe just my imagination. Its the first time Ive had the enging running more than a few seconds. It just kinda perplexes me. I figure if its the starter it would make a grinding sound not a turbo sound. I dont know. Id hate to take it somewhere and they tell me im crazy.
Burning Brakes
Joined: Mar 1999
Posts: 1,047
Likes: 3
From: CA
Having a hard time thinking of something that stays running after you turn off the motor other than the fan clutch, but you say there is no mechanical fan...so could it be your electrical fan than is noisy? Do it make this sound when the car is cold or only when fully warmed up? Or it doesnt matter?
Thread Starter
Racer
Joined: Apr 2006
Posts: 300
Likes: 0
From: Joplin Missouri
To help diagnois the problem I temporarily took off the electrical fan. I only leave it going for about 15 sec or so. There is no ac compressor and the power steering pump is off. Just the basics is hooked up. The only other spinning thing I can think of is the wp impeller but it should stop when the engine stops. Im not running vac to the head lights i converted them to electric actuators so Im not running anything to the vac tank. Im just confused.
Thread Starter
Racer
Joined: Apr 2006
Posts: 300
Likes: 0
From: Joplin Missouri
Im a DA. I figured it out. I had the starter interlock rigged so that I dont have to have the belts buckeled. I ran the jumper wire from a 12v source that came on from run not start. So it was my starter that was free spinning after engauging. Bubba hacked up my wiring harness so I went back and traced it from the ign switch and now it works like a charm with out the noise and no jumper wire. 