ok man i have problems i mean i have problems. I have had my camaro for seven years right. And since the first year i got it in the winter or whenever it is cold the damn thing knocks. Not at idle but at about 1500 rpm or so. I have been changing out stuff left and right over the years and it has been driving me nuts. Finally i put in a new 350 this summer and i about crapped when it started to knock on a cold day. I couldnt beleive it!!! So i thought must be the computer messing with the timing wrong. So i droped in a new vaccuum operated distributor and it still knocks!!! i cant beleive this thing. I am about ready to run the thing into the river. The only thing i can think of is the heat riser thing. but dont those usually tick when they are bad. This sounds just like a rod bearing. Any suggestions guys? Any ideas would be appreciated very much. Thanks.

86coupe

------------------
86 Coupe with a ton of fact. options G80 (now with 3.43's)Four wheel disk, T-5, (now a world class T-5), T-tops
Mods- IROC Front and rear anti sway bars with energy suspension endlinks and i also added the wonderbar, No exhaust after the Cat though fell off and to cheap to buy a 3 incher yet so I have to be quiet. Fourth Gen seats now. LM1 350 Crate engine!!! Good no more LG4 evil bad naughty things. Still seem to get descent Gas mileage. All major computer stuff hooked up and running good.

 

did you build the first engine yourself or was it in the car?

 

Engine was rebuilt by a guy who really knows what he is doing soon after i purchased the car. He completely went through the thing. The 350 that is in there now is the LM1 replacement engine. As far as i can tell i there isnt anything hitting the engine you know like fuel line or something on the air injection thing gong to the cat. the really bad thing is it make the exact same sound exactly. I think i may be the heat riser thing but i have not heard of one being so loud and sounding so much like a rod knock. If it is a hot day out it will not do it. Only on cold damp days or really cold winter days. Which is what leads me to think of metal things being a bit smaller when it is cold. This thing realy has me stumped i mean i am going to buy me a new Z or SS but probably not till 2002 or at the very soonest for a year. Any more ideas? Thanks for the respose guy.

 

Are you using decent gas?

 

I had a similar problem with a 87' Thunderbird 5.0...had rod knock, i took the motor out, tore it down, put new crank and rod and main bearings in, reassembled it with a new oil pump and the damn thing started knocking again like 2 weeks later...
never figured out why, i just sold it



------------------
~Sp33d~
(sold)1989 2.8l 5-speed RedBird w/ flowmaster, cold air intake, TRW cam. Audio system includes-Cadence component plate 4x6's/Cadence 3way 6x9's,300watt amp to front speakers/400watt to Blaupunkt DVC 12" sub.

 

Engine mounts? Transmission? Since I do not know what the noise sounds like, it's just a guess based on what you stated. Some other questions that would be relevant to me are:

1. Does it only knock (ping) under load?
2. Does it always knock (over 1500rpm) when cold? If not, what changed (temperature, engine speed, rain, etc.)? How warm/hot does the engine have to get for the noise to disappear? Is it gradual or sudden?
3. Does the knock vary with engine speed? If so, does it get faster with speed, or does it diminish?
4. Does it knock in neutral (stationary) only?
5. Does it knock in gear (moving) only?
6. If a manual transmission, does it knock with the clutch depressed?
7. If an automatic transmission, does it knoch with the brakes applied and the engine at a speed when it knocks?
8. Does the knock ever disappear? If so, when?

Two different engines with different distributors (one a vacuum advance) makes me suspect that it is something other than internal engine noise. As the post above stated, check the gasoline.

My suggestion would be to locate the area where the noise is coming from. A good way would be to buy mechanic's stethoscope (< $10 at any good automotive parts store) and locate the source of the noise.

Using a length of washer hose or a screwdriver held to you ear may work, but I think a stethoscope will pinpoint the noise better.

If you can at least isolate the source of the noise to inside or outside the engine, you'll be closer to solving your problem.

[This message has been edited by Stuart Moss (edited September 22, 2000).]

 

Ok to answer some more questions. It doesnt matter if the cluch is engaged or disengaged. Plus i have a diff. clutch and even a newer tranny than what was originally in it and it knocked the same way with the old stuff. It does seem to vary in RPM but not consistantly i dont think. If that makes sense. I think you are right about the tube or a stethescope for determining where the noise is. I recently put on a 3" cat back so my car is a lot quieter than what it was before. So hopefully that will help out in finding the culprit. Oh it doesnt knock under a load. And it doesnt matter if i have the car in gear or not it will still knock. The knock does seem to dissapear if the egine gets really hot or at least fully warmed up like if it has been above 180 for a while then things quiet up and you cant hear anything. Also it will knock sometimes at lower rpm's i have seen it knock when just barely above 1100 rpm. I dont think it could be engine mounts cause i inspected them when i pulled the old engine out and put in the new one. Any ideas? Not sure when i can take a look at it again but man this thing is agrivating. On the bright side it does haull ****. Thanks for the help. More ideas anyone?

 

Ok so i did some checking tonight and i hacked up the heat riser eliminting that as a problem and when i put the thing back together i noticed that there was a pretty healthy crack/rusting going on on the flange that fits with the heat riser housing. Could this make such a leak noise that it would sound like a knock???

 

From your original post, it sounds like you start the car, run the engine up to 1500 rpm, & at that point you here a knock. It even does this with a different engine! Correct so far? If so, disconnect the serpentine belt or all the individual V-belts (don't know what your set up is) & repeat the above start up procedure. If the noise isn't there, it's your belt drive system or one of the components being driven.
Regards, FJK

 

Exhaust leaks often are loud when they're cold, but then when the metal heats up, the gap shrinks and they shut up. If you have a known exhaust leak, a good place to start would be to fix it regardless of any knocking noise. Usually you can see an exhaust leak: there will be black dust all over everything around it. A very common place for a leak is where the manifold meets the head. Usually that will make a slight ticking noise at idle, but a loud noise when the engine is at low RPM under load.

I doubt that what you have is anything serious. With 2 different motors making the same noise over a 7 year period, you aren't going to blow up or anything. Use a piece of heater hose; stick one end in your ear, and listen carefully all around the exhaust right after a cold start-up. I'll bet you'll hear it.



------------------
"So many Mustangs, so little time..."

 

All I think it is is that camaros are cold natured cars. Mine does it too. Well...What do you mean my knocking? Do you mean it shakes like hell? Cause if so so does mine when i shift into 2nd. It shakes like hell. Hope I helped ya out!

 

Sounds like you ahve an exhaust leak from under the hood to me. I have one and it does the same thing it is like a clicking sound coming from under the hood.

------------------
TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."