Shake Zula

After having the car for a couple weeks now Ive noticed some things:

Sometimes when shifting into reverse it would make one loud metal on metal sounding clank. It hasnt done it lately though.

Theres a slight ticking sound comming from under the car, could be an exhaust leak, but the exhaust is all original, 39K miles on it, not much rust on anything. Sounds more metal like.

And what worries me the most is a knocking sound (rod knock sounding) but its best heard when sitting inside the car, windows up, at idle. Gets more rappid with engine speed but not louder. Listening to it under the hood, you can't hear it as much. So its mabey comming from the tranny area?

So this all could be just an exhaust leak? Broken flexplate?

I tend to worry too much about everything, so theres also the possibility that these sounds are just the normal sounds the car makes... Other than these things the car drives great!

84z28350

I would check your TC bolts, and usually if its a rod it will rattle off and on and eventually jump out and try to bite your fender

Shake Zula

Ive had a 355 that knocked bad. All bearings were destroyed. This 305 though dosent knock anything like that one did. This "knocking" can only realy be heard from inside the car

Shake Zula

Just having been through the unpleasent experience of having a knocking engine before, I become paranoid at the slightest sound of a "knock" type noise... So, if an engine has a rod knock, dose the knock sensor throw a code? Or is that the other kind of "knock"?

Stevo

iTrader: (45)

ya do know about the fuel injecter ticking right? sometimes it can sound pretty loud if u just listen to the motor at idle windows up like u said...

Also i gotta small exhaust leak tick...like u said i got no rust anywere but under my driver side exhaust manifold(stock) part of the gasket fell down and u can see part of it may want to see if its like that anyweres on urs. I gotta replace the gasket its really not a loud tick but its there.

and 1 more thing about the reverse metal sound when i put my car in reverse sometimes i here a click click twice never known what it was.

On hills and what not its harder to put into reverse and sounds loud and clanking like when it goes into reverse. I also replaced my U joint that didnt do much to that.

84z28350

I used to have this lovely sounding knock, thought my motor had gone south. Turned out my exhaust was so close to the crossmember it would tap on it, mostly while idling though.

Shake Zula

I think I'll go on a journey underneath tomorrow after work...

Shake Zula

Ok, I got under the car and checked everything out and listened to different areas while it was running. Heres what Ive found:

I can hear a faint knocking noise when my head was directly under the tranny pan. It didnt sound bad, probably nothing.

The ticking sound seems to be comming from the top of the bellhousing or very back center of the engine. It sounds mostly like an exhaust leak, but with more of a metal chatter tone in it. Dosent sound like a lifter tick. Not sure if its anything...

The loudest knocking I think is comming fromthe Air Pump actually. Can the air pump make a rod knock sound?

I use the term "rod knock" alot, but dont be confused, I dont think I have a damaged rod bearing. Cuz if it was, it would have to be a factory defect, and what are the chances of that?

I also heard a hiss after I turned the car off, and found one of the vaccum lines to the emmisions canister had a small tear in it.

Shake Zula

I just tired doing the stethoscope thing, couldnt realy pinpoint it

Shake Zula

Tomorrow Im gonna take the belt off and listen to the engine without the pulleys going. Hopefully the knock type sound will go away.

84z28350

^^

That would be the first thing i would do if i suspected the air pump, who knows maybe your pump has gone south on ya.

Be sure to report back with your findings.

Make sure you dont run it too long without the belt on

88305tpiT/A

iTrader: (2)

The clank noise going from D to R or R to D is usually a u-joint or an output shaft bushing.

Shake Zula

Man am I getting frustrated. Im about ready to take the car into a "professional"

Took the belt off: No effect.

Used a crow bar as a stethoscope: Couldnt find the knocking, everything sounded normal through it. The sound is most obvious when sitting in the car at idle. If I put my head under the car by the tranny I can kinda hear it at idle. If I Put my head by the engine I cannot hear it at idle. When I push the throttle I can hear it by the engine, around the #2 cylinder, upper part, but it also is obvious around the passenger side pulleys. I cannot pinpoint it

It scares me cuz its sounds like a rod knock, but it dose not sound to be comming from the bottom end. Either top end, front, or tranny. What can I try next? Can a bad lifter make a sound just like a rod knock, but no ticking at all?

Shake Zula

Not sure if this can be considered at all, but...

When my 355 has a rod knock, it made about 4-5 knocks a sec, and it idled at like 800rpm. Ive heard of vehicles with rod knocks and they made about the same. But my 305 makes these knocking sounds at about 7-8 a second, and idles at 650rpm. Is that too maney a second to be an actual rod knock? Or is there no such thing?

sellmanb

have you verified oil pressure with a mechanical gauge?

If you have good oil pressure, I wouldnt think it to be a "knock" as in... bearing... at all.


Clunk when shifting through gears, or going into gear can be many things.

U-joints, output shaft.... or TV cable tension, too high of idle (not this one apparently), transmission mount, motor mount... etc....


Have you adjusted your valve lash?

Have you tried running a little seafoam through the vacuum lines to get it to smoke, so you can see if you have any exhaust leaks?

It can be one thing, or it can be several things leading up to th several knocking sounds.

Shake Zula

Stock electric oil pressure gauge, 50psi when cold or when driving. 30psi at idle when hot. Can the stock gauge be trusted? I have not done anywork to the car except an oil change with standard Valvoline 5w30. Whats seafoam?

sellmanb

the stock gauge sucks. definetly invest in a mechanical gauge. they arent that expensive.

Seafoam is sort of a cleaning agent that you can find at a lot of auto parts stores. People put it in their gas tanks, through their vacuum lines, and I hear some put it in their oil too (though I dont know if I'd do that one ).

Disconnect a smaller vacuum line that attaches to the intake manifold, and take a cup, put some seafoam in it, and put the vacuum line in it (dont let the car bog out, rev it to 1500rpms or there-about, that is where vacuum is best typically).

When it gets combusted, it should come out as white smoke, and you should be able to see where the exhaust leaks are at.

Shake Zula

The "knocking" sound seems to get louder as the engine gets hotter

sellmanb

probably pinging.

How does your coolant look? Take some out and put it in a cup. Does it look really watery?

Should probably do a tune-up if you havent already.

Shake Zula

It looks like theres more water than coolant...Its not real dark green.

A while ago I put fuel treatment through it and checked all the plugs, they were good.

5.8L Camaro

And I didnt think pinging occured at idle

Shake Zula

This is realy getting on my nerves! I drove the car 30 miles, let it idle till it reached 220 when the fans kick on, and I can clearly hear from inside "knock knock knock knock knock" I get out of the car and stand by the hood and cannot hear any knocking. I drive the car another 30 miles freeway, come to a stop cooled to like 180 and can faintly hear "knock knock knock knock knock" I want to put a thicker oil in to see if that has any effect. What should I go with?

Shake Zula

Possible find!

Put in 10W40 oil, no effect on the knocking sound.

So I got out the stethoscope(crowbar) and began listening again. After about 10min of searching I touched the metal fuel lines and hear "knock knock knock knock" and its the same speed as what Ive been hearing from inside the car, and gets faster when the engine goes faster. Do I just have realy good hearing and this is normal? Or is something probably wrong?

rjt76

lifter or lifters are probably noisy.