Anybody's SC sound like a Helicopter?

rickbtbird

Registered User
Ok I got the car last year and drove it back from Florida. It's always had this motor, tranny, or exhaust thump that similar to the heart beat of a helicopter. At idle it’s as smooth as my 90.

Since then, I've replaced the (broken) motor mounts, (warn out)tranny mount and bushings, rebuilt the (nasty) injectors, resealed the intake with new gaskets, replace the radiator (that had a hole in it) and the thermostat (that would only open a 1/16th of an inch).

I also installed a new SD coil, NGK Iridium sparkplugs, taylor wires, cam sensor, IC gaskets, and a under drive pulley set.

I have no CEL and I ran a computer balance test on the motor (and it passed). Outside of my blower maybe needing a new coupler (there is a little slop in it), the shiffer chatters a little a low speed so I'll have to rebuild it this fall along with the blower.

I have an SPC upper exhaust system ready to install but the Bill accidentally send me a drivers side down tube for a 89-93 so that's on hold for now.

I have a receipt where the clutch was done about a year prior to trading it to a dealership.

I'm stumped about the heart beat noise. The car pulls better then my 90 but dogs a bit unless I up shift from below 1.2k rpms during 3/4 throttle. This and the heartbeat keeps me from driving it as much as I do the 90. It's so much smoother but it has an AOD.

Anybody have any ideas?
 
Maybe a blown head gasket that leaks on the outside of the head? Can you get a sound clip? I know my digital camera does video as well as my wifes cell phone. Just an idea...
 
That what I was thinking the first time I noticed it after buying it but the compression test are ok.

The wife has a new camera. I hate asking her how to use those things because she always forgets to tell me something so I end up spending an hour reading the book. Then work pages me about some problem they can't solve and then I forget what I was doing and have a beer. Two day later while I'm driving the helicopter I remember that I was suppose to do something :eek:. I'll get it out and soon as I can.
 
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That what I was thinking the first time I noticed it after buying it but the compression test are ok.

The wife has a new camera. I hate asking her how to use those things because she always forgets to tell me something so I end up spending an hour reading the book. Then work pages me about some problem they can't solve and then I forget what I was doing and have a beer. Two day later while I'm driving the helicopter I remember that I was suppose to do something :eek:. I'll get it out and soon as I can.


can you feel it or is it just sound

my dad has a 95 na bird.. sounded like a helicopter i guess if thats what you wanna call it..

his sounded like a stick rubbing the tread of the tire.. turned out to be that wheels, wheel bearing.. just an ideo i have no clue if its close or even your prob.. but worth a try..
 
I'm 100% sure it's the result of or is a condition of the motor. It doesn't do it when it rolls at idle. If I get under the hood after it warms up there's a drone noise that comes from the back of the motor on the passenger side. I thought that was maybe the EGR having some issue but now I'm starting to wonder if the head gasket on that side is beginning to go.

I also have a warm condition when I drive it on the hi-way and it cools down when I drive in the city but that's in another thread. Cooling system is new. My 90 stays the same temperature almost all the time after at full temperature.

This winter maybe I'll do the head gaskets as a last ditch effort to get ride of the heartbeat and salvage the motor. If that doesn't help I might put it on the lemon lot as a fixer-upper for someone that has lots of time to go through it. With three other cars to maintain I can't have one that takes 80% of my efforts.
 
Might want to check on all the bolts holding on the exhaust manifolds to the heads... if they work loose....
 
Yea I'll have to dig into it but, right now I'm behind on other matters like the house and the yard. Better get to that before the wife hires and handy man and who know what that could lead too.
 
had the same noise on the right side of the car when i bought it , new exhaust manifold gaskets and tight bolts fixed it , but i also replaced the hgs so could be either or.
 
It's an exhaust leak for sure

I'm 100% sure now this is an exhaust leak coming from the passenger’s side. Last night I had my head inside the engine bay where the drone noise was coming from under the the back of the throttle body and the fumes were making me gag. I guess I'll need to remove the intake and start looking at the exhaust manifold bolts torque and compression test for head gasket seepage. Wish me luck! :D
 
I found a leak. I had to get under the car and it's leaking where the pipe meets the manifold/cat attachment surface. Geeze this will be the third time I've torque these bolts down. The book say's 25-35ft-lbs and I'm using a torque wrench.
 
YES!! The bottem bolt didn't have enough torque on it. I must have got a bad reading the last time I check it :eek:. No more Helicopter.:D
Moderator, close this thread please!
 
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