Arjian

Hi everyone,

I'm from France and new on the forum. It's a mine of gold to get some informations about corvette. I also decided to register.
I just bought a black C6 Z06 2007 last month with 45000km and an awesome Borla Attak Cat-Back.

It was all good until last week, a strange "tapping,ticking" is appeared.
I was immediately coming back home to control the rockers as we all know the famous "rockers bearings" issue.

No broken rockers or bearing, but a lot of play between the bearings and the trunnion. I also decided to order a Comp Cams trunnion upgrade kit to prevent any damage from those rockers.

Ordered on sunday, delivered on friday by Fedex straight from Florida.
I just instal all those upgraded rocker on the engine today, torque it nice and clean to 22lbs/30nm and start the engine. No more "tapping, clicking" or whatsoever strange noise. But after 3 to 4 minutes on idle, the engine start to heat and the noise is back, 100% like before.

It also was not the problem. I decided to make a video and to post it on youtube to got some advices about it. Here it is :


(I put some infos in the description)

I thing on bad lifters, to me it's the only last thing who can produce that noise. Push rods are all ok, same thing for the valve springs.
And as I say in the video description, the noise seems to come from the middle of the engine (under the intake manifold) where are the lifters..

No power or engine start issues, turn well.. Some idea, advices ?

Thanks a lot by advance to all for your help and sorry for the eventual spelling mistakes.

Best regards from France.

Rock36

With that sound, I'm going to say you should definitely have your lifters checked.

That is much louder and distinct from the typical ticking noise described here on the forum, especially since you already checked and replaced rockers.

240sx2jz

Yea, what rock said... Get them lifters checked

ramairws6

Oh boy, thats not good. Sounds like a rod or main bearing from that video. So hard to tell over the intrawebs though...

mariofromnewyork

I don't think its a sticky lifter.

Time to pull the heads!

Rock36

Yeah, I hate to say it, but that is also a definite possibility based on that clacking noise.

Turbosixx

Doesn't sound good at all. I would not start it again. Sounds like its in the bottom end.

jedblanks

Did you use the stock bolts through the aftermarket trunnions?

The ones the come with the kit are way too long. The stock ones are ALSO slightly too long. Either grind them down a bit or use some washers on top of the new trunnion. The comp trunnions are thinner on the part the bolt goes through than the stock ones.


Edit... Just played the video. Sounds like something in the bottom end.

Lifters are under the heads. The pushrods go through the heads and sit in the lifter cups. The other side of the lifters ride on the camshaft. Sounds like a roller is eating into the cam to me. Could be a bad camshaft?

z06 driver

Just listened to your video and that sounds really bad. I would not drive it until you get some good ideas what is causing the noise.

Arjian

+1 for Rock36 and 240sx2jz ! As I said before, I checked all the push rods, valve springs and exhaust leaks. No problems on those 3 things..
How can I know if the lifters are bad when I got them in my hands ?
I had previously tried to push on the push rods to see if it moves down but with no succes. No move at all

Ramairws6, I don't think so, I had previously show some rod bearings issues on youtube and the "tapping" is really much more louder and much more like steel on steel.

PS: I just remember that the noise appears the day where I add 50cl of oil in the engine. This day I had checked the oil level, (at 80°C 5 minutes after stop the engine, I know the procedure) and it was on the middle, I also add some 50cl more to get the good oil level.
Could that make some bad residue rise to the surface and clog the lifters ?

Arjian

Yes I agree to not restart it before I know what's that !
Yes I use the stock OEM bolts for the rockers, the Comp Cams bolts are in fact way to long

Arjian

That's a broken rod bearing:


Way much louder than my noise and pretty different.
And as I said, my engine turns really good, idle well, revs well and no power loose or so on..!

Undy

I'd pull the oil filter and cut it open to look for metal/bearing debris. I agree with the others, don't run it until you find out what the problem is.

don7790

I would start killing the cylinders one at a time. If the noise goes away you know its a rod. Would eliminate that possibility first.

ramairws6

I'm sorry to be a Debbie downer but that sounds like a rod or main bearing then a lifter for sure.....

Arjian

don7790, what are you meaning ? To unplug 1 spark plug at a time ?
Undy, I also have to do an oil change ?

I just see 3 videos on youtube, with lifters problems and it's exactly the same noise at idle (they don't rev it in the videos).




3 times the exact same noise than mine.

camirocz

your engine is knocking not ticking.Il y a un cognement qui vient du bas du moteur.

camirocz

Crankshaft bearing for sure. Spun bearing ,stop driving it immediately.Ca n a rien a voir avec les lifters ou le haut du moteur.

don7790

Just try pulling a plug wire off the plug and killing the cylinders one at a time and see if the noise stops or gets a lot less. When the clylinder that has the bad rod is killed the noise will become less. That wont happen with valve train noise. Just what I would do if it were my car. Sure sounds like a rod knock to me.

Arjian

Ok I understand ! I will check this tomorrow !

Carmirocz, tu parles français ? le claquement me parait similaire aux autres vidéos. Ce que je trouve bizarre c'est que c'est arrivé tout à coup après avoir fait le niveau d'huile.

The noise is for me the same than of this 3 others videos. What I find strange is that the noise appears the same day I had check and add some oil.