drewdiamond

I seem to have this strange ticking sound above 1200 RPM's on my 86 trans-am. Sounds like it's comming from inside the dash. I can replicate the sound when the car is stationary by reving up the RPM or just driving. It's not the heater, checked that, and can't hear it from the engine compartment. The car is also a manual. Any thoughts?

Rob Wade

Little more info!? Does the tick get faster as the revs get higher? Does it change or get louder or quieter? Is it worse when its cold and quiet down when its warm? Need some more input.

drewdiamond

It seems to get faster as the RPM's increase. I don't think the temperature has any input. I usually don't hear it when I first start the car but starts to make it's presence during the ride. There are also times it will go away but then come back. I'm thinking something with the tach?

purg3d

hey pal i have symptoms similar to yours. Sounds like an electrical "click" rather than engine-related? I isolated mine to one of the relays on the firewall. Only occurs when the engine is warm?

I was thinking it is cooling fan related, but never really bothered to check since my relays arent mounted to the firewall... could be tach?

Rob Wade

Are you sure it isn't a manifold at the head exhaust leak? Back ports. Its not uncommon for the bolts securing the manifold to the head actually fall right out. This will give you a ticking sound something like a lifter tick since its only one port leaking. It will rise and fall with the rpm's of the motor and since it may be right at the rear of the motor it will come through the firewall.

drewdiamond

I can't say that I have checked the manifold, but I would expect that if that were the problem I would hear it all the time. As I indicated previously, the noise starts around 1200rpm. It also will stop on occations and run fine for a preriod of time. I will take your advice and check the bolts just to make sure. Any other suggestions would be appreciated. If I can provide any additional information, I will do so.

Thanks.

camaronewbie

Check exhaust for leaks. Also have you checked oil? Valves will tick when oil low - not getting enough lubrication. Also may have a loose rocker arm, but I'd check other things before adjusting valves. Fuel Injectors will tick also, but they don't necessarily change with RPM. Check exhaust and oil first. Exhaust may be tight, but gasket may be split, or have a hole in it.

drewdiamond

Checked last night, no exhaust leaks, plenty of oil, it's not fuel injected, engine is very quiet. The sound is definitely coming from inside the dash right in the middle. I think my next step in to remove parts of the dash and see if I can find something. Could it possibly be the VSS? I was told that it is located in the dash. Since I've had the car I get the trouble code (check engine light)for VSS until the car is in motion then is goes away.

Rob Wade

The VSS should be cable actuated and therefore you shouldn't have the noise if the car isn't moving? Strange. I can't think of anything under the dash that should give a ticking sound over 1200 RPM.

coolram62

iTrader: (2)

I have a friend with a '91 3.8 Bonneville that does this at idle.The ticking comes from behind the right side of the dash.There are relays mounted there and more than likely it's one that the coil is getting weak and not holding as well as it should.But still doing it above 1200 rpm does sound unusual.My '73 CST has an exhaust tick,it's a leak where the right down pipe bolts to the exhaust manifold,but it's only noticeable when she's cold and not intrusive enough at that for me to try my luck at breaking a flange bolt.