zer0321

broken camaro

CaliCamaroRS

2 possibilities are spark knock and rod knock. They both create 2 different, distinct sounds. A rod knock will create a deep, low, thunk...while a spark knock will create a loud and quick clack.

Since you mention timing, it's most likely spark knock. This can occur when timing is incorrect. Check timing again. Also, try to avoid prolonged engine run time while the engine is knocking. Spark knock can cause a lot of damage.

Some possible causes:
-Is the distributor loose?
-How old is the timing chain?
-Is your EGR valve fuctioning?

EDIT: You mention that after being smogged, the timing was way advanced. Typically, you would retard timing to help it pass emissions. Interesting........

zer0321

The timing chain is "supposedly" brand new according to my receipt from MasterTech Automotive

The EGR valve definatly works

The distributor is surely not loose, because it barely moves even when you hit it with a hammer (really really stuck!)

from what you say it sounds like it's a spark knock.....and it was driven a good 40 miles (mainly highway) on it.....doh

what damage could have occured from the spark knock?

I will try to get a sound clip of the knock sometime this week.....

CaliCamaroRS

I'd check timing again. It does run like crap when it's knocking right? Does anyone know if the carbed 2.8 uses a vacuum advance distributor or an EST module?

Lets see, not enough fuel can cause spark knock, overheating, spark plugs that are too hot(if they tuned your motor, they might have put the wrong plugs in), carbon deposits in the cylinders, or a spark plug wire touching another and crossfiring through it. Plus some other things i'm probably forgetting.

Oh yeah, when spark knock (aka detonation, knocking or pinging) occurs, you basically have air/fuel being ignited by the spark plug AND air/fuel being self-ignited by excessive heat. This creates TWO flame fronts instead of one that have damaging effects. It can damage head gaskets, burn pistons and valves, or break rings. Not cool.

zer0321

yeah the car runs like complete **** on wheels since it's been knocking......

I will check the timing sometime either tommorow or the day after....if something is damaged from the spark knock will it make noise after i rid the car of the knock?

loomdog32

did the knock start like a light ticking and progress into sounding like someone hitting a building w/ a sledge hammer? that what my carbed 83 sounded like.. it was a lifter knock.. there was someone on here that had about the same happen to them.. IN MY CASE, the engine was dead.. i would think the same would be true in your case.. rebuild.. buy used (3.4 comes to mind..).. buy rebuilt or crate engine..

when there engines knock, there USUALLY dead.. sometimes not.. IMO ur best off replacing the engine..


-mike (loomdog)

TomP

Wow, why'd you hit the distributor with a hammer?? Did you loosen the hold-down bolt? Did you get the right mark on the balancer for #1 TDC? And I assume you used the front passenger side cylinder as #1- NOT the driver's side. The #1 on a 2.8 is front PASSENGER, regardless of what v8's are.

zer0321

yeah, we followed the haynes manual when we adjusted it...so i knew the #1 cylinder is on the passenger side (it's actually a little bit farther forward than the one on the drivers side also....according to haynes)...after we loosened the hold-down bolt on the distributor, it still would barely move (actually the mechanic I took it too told me this first...) and when we adjusted it ourselves it took much prying and force to adjust it to what we thought was the right setting.....

86bird_28v6_5spd_ramair

sound way to familar. few years back a friend bought a 84 camaro with a 2.8 about 3 month later it started knocking.

he use some stright 50 weight oil to help but it eventualy blew.

sure someone else did not fill it with super thick oil to sell it???

what really sucked for him was he spent like 1500 and got a loan out on it.

if he had waited one more day I found him a firebird with a 400 and stick for 800 bucks.

we teased him often or every month as he sent in his payment for a car he no longer had.

this was before I knew very much about thridgens. also they guy selling the bird was selling it cause it ate trannies like candy.

well duh a t5 will not take a 350 let alone a 400.

TomP

Yep, if you look closely, the front pass cylinder is closest to the timing chain, and that "always" denotes the #1 cylinder. Okay, I thought you just started whacking the distributor without loosening the hold down! Sorry! It could be that the distributor o-ring had "melted" in place, and was preventing the distributor from spinning. If you have an oil leak from the rear of the engine, it's probably this o-ring. (It's a common leak spot on the 2.8/3.1's).

Have you thought about pulling the distributor and rebuilding it? I'm not quite sure what electronics are inside the carb'd distributor... maybe the 4-pin module (instead of our 8 pin computer controlled module)? In that case, you could put the MSD hi-po 4-pin module in.

I'm inclined to think along the lines of Dan... that something's wrong with the timing. Have you checked the spark plugs? If timing is way overadvanced, the detonation will result in a damaged spark plug. (My timing was overadvanced so far, once, that the whole center tip of the #1 cylinder's plug was GONE! Scary stuff, makes me wonder where all that went. That cylinder now has the lowest compression out of all 6.) I wonder if they didn't install the timing chain "straight up", and they put some advance/retard into the CAMSHAFT timing. If that's the case, the front cover would have to be pulled, the timing chain pulled, and the chain re-installed. An aftermarket chain's crank sprocket usually has 3 keyways- 0 degrees cam timing ("straight up"), and then an advanced setting, and a retarded setting. Anyone know if a stock timing chain has those keyways? The Cloyes true dual roller chain (the one I put in) has it, but I don't know if a stock chain would've bothered.

KED85

The engine is dead.
IF ANYTHING, take the repair shop to court.
BUT, long time has passed.
You're s.o.l.
It is a dead engine, now.
Really
Drive it until it explodes. Rod knock is very common. Really
The engine is dead.
Sorry
You got screwed by repair shop.
I've been there.
Take them to court, scare some money outta them.
Slip in a 3.4 and have fun.
Really the engine is dead.
Rod knock only goes away-
By blowing the engine apart
Removing the dead carcass.
I've been there.

kvu

true dat

85CamaroRulz

Had the same problem dude, I had my buddy put in another engine out of a 87 Firebird 2.8, He had the old one out and the new one in, In a little less then 2 days, The engine only has 51,000 miles!!!! I paid 200 for it and paid him 200 for putting it in. Find a cheap engine man, Your engine is hot, That's defenitley a rod knock, And if it was a spark knock, U really screwed it up by driving that 40 miles, I would replace the engine or just sell it for parts

zer0321

sounds like I am screwed on this one.

KED85

You're ideas are great.
One of them will work out well.
Use 50 weight oil, it works GREAT!
I used 50 weight in my rod knock Chevy 350 for MANY MANY MILES & high RPMS too.
I drove my 67 Camaro RS/SS 4-Speed convert, top down, up & down the California Coast and raced up to 100MPH against a Mercedes.
I even sold that rod knocking V-8 for $200!
I made the guy listen to it before he said yes, I'll buy it.

zer0321

I have lots of ideas, but no money
now all I gotta do is choose what to do next