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PLEASE Don't Tell me! Need Extreme Help!

BigRed

Well-known member
Joined
May 23, 2001
Messages
948
Location
Edmonton
Corvette
1985 Bright Red Rocket
Ok from my experience's my problem sounds like a main bearing has been thrown however Im not sure as I saw a streamline of smoke eminating from what I THINK is the Knock Sensor.

When I start my car (And I mean this is in the last 3 days) It SOUNDS TERRIBLE BUT starts! It sounds like theres pistons on the BOTTOM of the engine..makes a Whirr whirr knock knock noise (Really terrible) but after it starts it runs as usual FINE!

Of course this is making it harder and harder to start.

Now the Oil's fine, Car after started runs fine but heres where I saw the smoke.

Passengers Side between the two last pistons (Toward the Firewall) ((Between pipes on the exhaust manifold)) there is a BRASS Fiting thats where I saw this streamline smoke and It smelled REAL bad.

Hope you guys can help me out
 

compyelc4

Well-known member
Joined
May 1, 2002
Messages
607
Location
Dayton, Ohio
Corvette
'95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
Before you get hysterical on us, check the flywheel. All bolts tight?
 

compyelc4

Well-known member
Joined
May 1, 2002
Messages
607
Location
Dayton, Ohio
Corvette
'95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
Oops! I did not read your entire post. Forget the flywheel.
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
I'm reaching for straws here, but when my cats went south, there was a terrible racket coming from what I thought was the engine. If it was rattling, it ran fine, but as soon as they quit making noise the car ran like crap -- wouldn't get out of its own way!

The catalyst had broken up and was rattling when loose and then occasionally they would stop making noise and would plug off the exhaust, thereby prevent breathing. You might want to explore that possibility.

I thought for sure they were rods knocking on mine at the time.

_ken :w
 

BigRed

Well-known member
Joined
May 23, 2001
Messages
948
Location
Edmonton
Corvette
1985 Bright Red Rocket
My Cats are empty Ken but ya Ive gone through what you did on my 318 Jeep.

The sound is certainly coming from the motor. I mean if you take your "normal" starting sound now knock off about 8 Music notes of it (Hence more baritone sounding) thats what Im getting and its a Whir whir with the car shaking and knocking. It seems the "Turn over" has to catch up with the Racket the cars making it want's to start gradual to the sound of the noise.

Its really creeping me out. But I think Knock sensor because of that Brass fiting (Thats Im almost 100% sure is the knock sensor) I mean there was SMOKE coming from it Lol
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
That's probably it then; the sensor IS located at that area of the block.

_ken
 
S

Shadowing1985v

Guest
hmm

i own a 85
and i dont' think its your knock sensor man,, cuase i replaced mine
and all a knock sensor is is when the engine starts to shake
it tells your comptuer to shut off your idle control
and to shut off some other things

no oil get to it just a little antifreeze underpressure
i dont' see how it would smoke, i mean
 
Joined
Oct 30, 2001
Messages
2,273
Location
Glen Burnie, MD, USA
Corvette
1986 Bright Red Coupe
BigRed, the knock sensor is located just above the starter and essentially underneath the car (the passenger exhaust gets in the way when replacing). There's nothing there that'll smoke; it's a screw-in sensor (looks like your oil pan plug) and an electrical wire that snaps onto the end.

I have occasionally seen that same thin stream of smoke from my car, but without the banging noise. I think it's coming from part of the EGR system, since that's located back between those two last cylinders. Also, though, I have a valve cover gasket leak that drips oil when cooling onto the exhaust manifold back there. When I start it, the oil burns off slowly and smokes and smells something awful.

A guess: your starter gear is stripped (hopefully not the flywheel ring gear). When I bought my Vette both were bad and starting it sounded like whirr CLUNK CLUNK CLUNK <catch> run run run run run. As soon as I let go of the key, it'd sound fine.

If this *is* the starter gear, it's a pain to replace but a fairly cheap part (I think a rebuilt GM was $75 and you can get smaller (easier to install) aftermarket units for not much more). Do it soon, because if that IS the problem, it'll take the ring gear on the flywheel with it and you'll have to have the transmission dropped out to replace that part.

Good luck. Wish you were closer; I'd give a listen. Any way you can record and digitize the sound?
[RICHR]
 
Joined
Oct 30, 2001
Messages
2,273
Location
Glen Burnie, MD, USA
Corvette
1986 Bright Red Coupe
Oh, BTW - Shadow's correct. There's no oil associated with the knock sensor. It only has coolant behind it (see a much earlier post of mine for a humorous (now...) story on replacing one). Oil will drop from other places and cover it, though.
[RICHR]
 
S

Shadowing1985v

Guest
umm, i had smoke

but i fixed it i had the same problem,, smoke coming up from my leaking valve then burning
i think there was a time in the past i had something burn on that side that smelt like eletrical

but it only did it once,, sigh
it can't be your egr i don't think cuase thats just emissions and valcumes woudln't put out that smoke and 100 percent wouldn't give u a noise, where is the noise coming from
u need to get someone to look at the engine while u start it up to try to pin point where the noise is coming from maybe two things just went out at once or something gay like that, hehe

wish u luck big red
 
S

Shadowing1985v

Guest
here is a thought

maybe one of the spacers came un done on your starter
that will give u a clunt knock noise when u try to start your engine

that burning still puzzles me though
 

BigRed

Well-known member
Joined
May 23, 2001
Messages
948
Location
Edmonton
Corvette
1985 Bright Red Rocket
Sounds like in essence Im starter realted then...One Word..YAHOO Starter problems are a freakin joke to me, as I thought my thrust bearing or something a little more serious was wrong (Yall pbly see the tears of joy coming from me)

I'll have my trusty mechanic looks at all the possibiltys and have him just replace the entire starter (Why not I have a 400$ credit with him) ((Of course if thats the problem)) I'll also have him put my car on a code reader just for a check up.
 
Joined
Oct 30, 2001
Messages
2,273
Location
Glen Burnie, MD, USA
Corvette
1986 Bright Red Coupe
Shadow, EGR is more than vacuum - it sends exhaust back to the intake to lean out combustion and improve emissions. There's a clamp that attaches two of the EGR pipes that seems to forever be coming loose, and if your exhaust is smoking you'd get smoke from it as well.
[RICHR]
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Smoke

Could be coolant leaking from a freeze plug.

Could be Oil leaking from the rocker cover and getting on the CAT or the starter.

Could be you didn't get ALL the material out of the CAT and you got something still banging around in there.

BUT

Without exploratory surgery...it's hard to tell.

Over the internet
HARDER!

How many miles on the engine?

AND have you thrashed it...or babied it?


Stick or Auto?

AND have you checked you exhaust hangars..

Could be.. one broke loose and the pipe is banging against the frame?


( I know exactly where you are at... when my PRE cat disintegrated I thought I had a roller lifter failure... and FREAKED!)

Freaking Bad
Science ROCKS


Take your time and NAIL this problem.


I have seen VERY FEW L98 engines blow!

( unless driven HARD by 18 year old kids with NO oil )

Vig!

( Don't Panic!)
 
S

Shadowing1985v

Guest
yeah vig is right. L98 are like impossiable to blow

yeah u are right,, i guess the egr could smoke
 

spyysee

Well-known member
Joined
Jun 15, 2002
Messages
124
Location
NY LI Metro
Corvette
1987 black beauty, all ez mods, owned '62,'78
Had a similar problem in terms of noise. Tuned out to be the pre-cats.
I replaced the pipes w/ strait- throughs (no cats at all) and still
pass emissions w/no problem.

Good luck.
 

BigRed

Well-known member
Joined
May 23, 2001
Messages
948
Location
Edmonton
Corvette
1985 Bright Red Rocket
Cars got 140 000 Kilos on it I drive it like a Vette should be driven not easy but not freakishly hard.

Ive done alot of work to it:

Plenum/runners are ported
Valve Seals replaced
Air Foil
Intake manifold R&R from previous leaks
New Mufflers and half exhaust (To the cross over) ((All hanger good) ((Dynomax))
Centerforce Cluth w/ Centerforce TO bearing w/ New bushing
New Alternator (Last week) (Bosch)
New Battery (Rocky's)
New Plugs (Bosch +4)
New Wires (MSD Red 8.5's)

I know what Coolant and oil smells like this isnt coolant I also know what electrical smells like and this is REAL close to that BUT Even more RANK! Its very pungent

And this isnt a bang from a pipe or anything bolt on thats slaping around this is most definitly a internal sound (Which now Im starting to see as the starter being capable of making)

Im just on hold till next week for some lift time by the sounds of the concerns it isn't internal so I should be ok

Thanks all
 

BigRed

Well-known member
Joined
May 23, 2001
Messages
948
Location
Edmonton
Corvette
1985 Bright Red Rocket
Oh ya on the pungent smell, The starter is under the passenger side of the block correct? If its spinning a gear or striped it would pbly make a smell from the heat generated from friction Correct?

Thats my new theory.
 
S

Shadowing1985v

Guest
hehe

i realy dont know,, i don't think it would smoke,, but who knows im the same as u big red learning as it flows

i just found out my tps sensor was way off, i set it to 54 volts just now,,
im going to finally fix my car,, now,, with this corvette site help
 

rwd

Well-known member
Joined
Jan 22, 2002
Messages
234
Location
Yes
Corvette
Varies
Can't remember the C4 engine compartment layout, but could the smoke have been from the starter/solenoid overheating? I've seen that. Same for the bad smell.

I take it from your list it's a 4+3. You could try starting it by rolling it down a hill and engaging the clutch. If the noise still occured, it wouldn't likely be the starter.

Just checked my old reference stuff. The location is similar. There is also some sort of an 'overrunning clutch' assembly, which could also give off smoke. Definitely sounds starterish.

I think I'd find a hill and try starting it with the clutch. I know there's a safety switch, but it worked on my '85.
 

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