Engine Knock 3.6L

[caligrown562]

Last night I started to hear what seemed like a knock but not sure. I have had a rough idle for awhile now. Don't kno if that has anything to do with it. But last night I was listening to the motor and you can hear a faint knock noise repeatedly. It was very low and hard to hear. Could this be the start of a big problem?

[Chevrolet Customer Svc]

Sorry to hear about the new issue DjfunkmasterG, let me know if anything happens for you. caligrown562, have you been able to get your vehicle into your dealer yet? I know you've posted about a few different issues and haven't read of any results. Thank you for your time.

Jeff Morris, Chevrolet Customer Service

[Inuyashas_Brother]

It seems that a number of secondary factors can cause engine knock

The problem is most often noticed during hard acceleration AND hot weather. So during winter (and cold weather) the problem might be audible (and not even exists).

The short term solution is to use premium gasoline. If the use of premium gasoline defeats the engine knocking noise, that is 100% confirmation that it is indeed engine knock (and not other similar sounding problem).
===
Modern cars have engine knock sensor, and if engine knock is detected the timing is retard to prevent engine knocking. If your car has engine knock sensor and yet suffers from this problem it is very likely the knock sensor is defective. Otherwise the problem might be one of many things:

(a) A/F mixture too lean (bad o2 sensor?)
(b) spark plug too hot
(c) ignition (spark) timing too advanced
(d) MAP / MAF sensors - defective
(e) low fuel pressure
(f) dirty fuel filter
(g) vacuum leak
(h) engine (water) temp too high
(i) air temp too high
(j) octane too low
(k) bad fuel injector
(l) carbon hot spot
(m) failed knock sensor

http://answers.yahoo.com/question/in...5094152AAXWAZK

[DjfunkmasterG]

Why run premium and pay higher prices on a car that is supposed to run on 87 Octane?

If this was a supercharged 8 I would have no issue filling with 93 or 94, but a V6 stick, it gets 87 Octane.

[BUMBLE1]

I guess I get to join the club of knocking V6 motors.
Started knock just yesterday on my way to get an oil change.
If it has a load on it meaning giving it gas you can’t really hear it but let off the gas and it pops up big time.
Dealer told me it’s not a big deal but it is to me. The Camaro Super Fest is this weekend and I didn’t want to miss it knowing the dealer wasn’t going to touch it till next week.
Dealers told me go ahead and drive it and bring it in on Tuesday so I wouldn’t miss the Fest.
I sure hope this doesn’t turn out to be a rebuild but I do have 62000 on the motor.
Thank god for warranties.
I’ll post more when I find out what is going to be done.

[BUMBLE1]

OK looks like the bottom end of the motor is being rebuilt.
All covered under warranty, I would suggest to anyone that thinks the motor is knocking to take it in.
It’s not going to fix it’s self magically the knock will only get louder as time goes on.
This first started with a little knock but I didn’t think anything about it.
Before dropping it off it was knocking on every take off in all gears.
GM is standing up and fixing my motor that has 62000 miles on it, I stand behind GM.


Should have it back Monday or Tuesday next week.

[larryt1026]

this worries me...what does an engine knock sound like?

[DjfunkmasterG]

Originally Posted by BUMBLE1

OK looks like the bottom end of the motor is being rebuilt.
All covered under warranty, I would suggest to anyone that thinks the motor is knocking to take it in.
It’s not going to fix it’s self magically the knock will only get louder as time goes on.
This first started with a little knock but I didn’t think anything about it.
Before dropping it off it was knocking on every take off in all gears.
GM is standing up and fixing my motor that has 62000 miles on it, I stand behind GM.


Should have it back Monday or Tuesday next week.

Damn, you have 62K on your Camaro already? WOW, and I thought I drove a lot when I was putting 25k a year on a car. Now I am averaging about 15-16k a year (closing in on 40 so old age sucks)

I did have an 88 Camaro that I ran the odometer up to 42k in ten months, but I was 18 and driving everywhere I went... so, I dunno, I guess I don't enjoy driving as much as I used too.

Glad to hear they're fixing your engine. Although rebuilds suck... GM is getting cheap when it comes to engine replacement. :(

[BUMBLE1]

Originally Posted by larryt1026

this worries me...what does an engine knock sound like?

Start your car and start giving it gas slowly till you hit 3 RPM's, then start coming down slow.

If you don't hear a slight tapping noise then your ok.

I just got my Camaro back and it is very quiet compared to before.

Total cost was $2500 GM paid.

If you think it's making noise take it in, don't wait.

[HopeRidesAlone]

But remember our LLT motor has direct injection which has a high pressure fuel pump which produces a clicking sound which is very easy to hear at idol rougly 1 per second or slightly faster

[cmwalker12]

mine KNOCKS also, being towed as we speak, can't wait to hear what they think is the problem!!