Hello,
I have an 86 Camaro IROCZ with the original 305 which has ~100,000 miles on it. My problem is a metalic clank noise heard from the engine. In order to get it to happen, i have to rev the engine up and down. So, WOT... close... WOT... close... WOT "clank".... close.... WOT "clank".... close... WOT... close and so on. It doesn't happen every time, but rather intermintintly. the car runs absolutly great otherwise with no complaints... Originally the car had a Quadrajet 4BBL carb. Everyone thought it was the carb so i replaced it with a 89 TPI system. After the conversion, the car runs better than ever but i still have the clank. I know what a ping sounds like and this is much louder than a ping so im pretty sure it is something else. Also i should mention that i am going through transmission mounts like crazy too about 1 a month. Do you think the problems could somehow be related? I really appreciate your help in advance!

Thanks,
Derek S
1986 Camaro IROCZ
5.0L w/1989 TPI system
Emissions equipment and cat removed
700r4 with B&M TransPak
4:10 gears with Eaton Posi

 

umm hows your timing?

 

I have ordered a timing light to get an accurate reading on the timing. Do you think it is the timing?

 

could be pre detonating.

 

Say what? It's either pre-ignition or detonation.....2 different things....

This clank (a bad trans mount is more of a thunk, IMO), does it occur while you are still on the gas or once you let off? I.e: WOT - *let off*- clank/thunk

 

It seems to happen when my foot is going down... So while i am still on the gas

 

your right, i ment pre ignition

 

have you checked your motor mounts

 

Yeah, i heard someone else bring up motor mounts too... I suppose there is no easy way to check the motor mounts right? WIll i need to pull the engine out to check them?

THanks again

 

Put it in gear and power brake it. Have someone watch carefully from the side with the hood up. If the engine jumps, it's motor mounts. It should be pretty obvious. I had the bolts come loose for the engine mount bracket (on the engine) and it made alot of noise. It also jumped when I popped the hood and power braked it.

In order to get your "clank", are you revving it in neutral or is this while driving?

 

The engine moves up on the driverside about a half inch or so under a power brake... I get the clank reving the engine in park or neutral. It also happens in gear while driving... very inconsistant... Although if you let the engine come to 1000RPM and stomp the gas pedal and keep doing it 5 times.. 2 times will be accompanied by the clank. I don't have a timing light... but playing with the timing doesn't really seem to affect it . IE i can advance the timing where I am getting multipule pings and still get a clank, same as retarding it until the car barely runs. Everywhere inbetween i can get a clank. However, i cant get it to happen under a smooth increace and decreace in throttle from 1000 to 45000 and back. IT only seems to happen under a sudden change from low to high RPM.
THanks

 

Something lose on the out side of the engine or front end of the car. Crawl under, look at everything and grab hold to things giving them a good shake. If you have ever used an automotive stethascope it's good for pinpointing engine noises. Little weird the first few times cause you hear all kinds of strange noises with it that are normal.

What kind of tranny mounts keep tearing apart on you? Those round ones made in China? Did you try a poly one? Those are tough.

 

OK,
I found a poly trans mount at Shucks and bolted it in... Looks like I won't be taking the crossmember out again anytime soon! I searched the engine compartment for loose stuff and couldnt find anything. Beings i deleted all the emmissions crap, there really isn't alot of things that could be loose. The real puzzeling thing is that the engine doesn't skip a beat even when it clanks... :|