Engine ticking.

[allcoupedup]

(secret bubba trick)

I found that a long screwdriver with the tip on someting metal and the handle pressed up against your ear is a great listening device. It helped me track down a bad fuel injector on my wife's car --- could hear all the injectors ticking except one.



Brian

 

[wishuwerehere82]

OK boys, I'm going out on a limb here, but after listening to the video over and over, and looking at the spark plug pix, I'm guessing that #3 exhaust valve is sticking.

It's definitely a lifter slapping.
No backfire through the intake.
#3 plug looks like it is firing open flame(no compression).

I would:
Try putting some marvel mystery oil in through the carb and let it coat the valve stems real good and see if that frees up the stuck valve.

Do a compression test on it, and if the valve is stuck open it will show up there.
The troubling part is that the frequency seems to be twice the rpm of your firing cycle(based on the sound of the exhaust), which would mean that the valve is stuck open enough to be hitting the piston twice on the firing cycle.

It could still be a broken spring at the base that would be hard to see.
It could be a clogged or collapsed lifter too.
I would also expect to see a lot more oil coming out the rockers than there is currently.

The video helps a LOT. Can you get some closer shots of the rocker arms and valve springs on #3 cylinder?

 

[I_R_DA_ONE]

After looking at the plugs , it almost looks like no. 1 plug is not firing at all....make sure that your plug wires are connected to the plugs and it's not a spark arch that you hear.....Mike R

 

[Tyler Townsley]

I once chased a double-click noise is a friends 61 for years and tried all the tricks without sucess. He finally had the motor torn apart. The click was caused by a peice broken off # 8 piston. It was 2 in by .75 on the bottom of the skirt. It was held in by the shape and cyl wall. It would 'click' when the piston changed directions. Car ran fine but the click just defied everything we tried in the valve area for obvious reasons.

Tyler

 

[Jeff Farrar]

The video helps a LOT. Can you get some closer shots of the rocker arms and valve springs on #3 cylinder?

Here is a new clip of just #3. I don't think it shows anything new and it doesn't seem to be acting different than the rest. I played around again last night trying to narrow it down. Needless to say I am beyond totally frustrated. I know from last year that I already have a weak cylinder on #6 not bad but does burn a little oil. Might be getting ready for either a rebuild or a new motor.

Here is the clip.

http://www.pghtank.com/temp/mvi_2385.avi

 

[wishuwerehere82]

Sorry Jeff,

I can't really tell any more than before from the video.
I would tear it down to the short block if you can, to get a look inside, that's the only way I know to make sure.
You sure don't want to run it the way it is, and 4-5 hours taking the heads off isn't that much time to spend for a diagnosis. The cam may be shot, as well as the lifter.
And getting the heads freshened up wouldn't hurt things.

Good luck, whatever you decide to do.

 

[wishuwerehere82]

I once chased a double-click noise is a friends 61 for years and tried all the tricks without sucess. He finally had the motor torn apart. The click was caused by a peice broken off # 8 piston. It was 2 in by .75 on the bottom of the skirt. It was held in by the shape and cyl wall. It would 'click' when the piston changed directions. Car ran fine but the click just defied everything we tried in the valve area for obvious reasons.

Tyler

That's the kind of thing that I have found in the past with other engines, but don't like to think about in a Corvette.
That double clicking is worriesome whenever you hear it. It means the piston is smacking on something and that can't be good.

 

[cfour93]

Here is a new clip of just #3. I don't think it shows anything new and it doesn't seem to be acting different than the rest. I played around again last night trying to narrow it down. Needless to say I am beyond totally frustrated. I know from last year that I already have a weak cylinder on #6 not bad but does burn a little oil. Might be getting ready for either a rebuild or a new motor.

Here is the clip.

http://www.pghtank.com/temp/mvi_2385.avi

Jeff

Not sure if you noticed but from this video there is barely any oil coming from the rocker on the right in comparision to the others. With the mentioning of the #6 it's looking like a tear down would be your best over all option sorry but if you are experiancing other issues with other cyclinders this might be a good time for rebuild...