4Agze Engine Knocking.

[B.L.Z.BUB]

So I had this weird knocking coming from my engine, I thought it was the SC12 but I just replaced it and the noise is still there.

I'm 99% sure its coming from under the cam covers. All the timing marks line up and all the clearances seem fine.

 

It is fine until the engine warms up, only happens at idle. The car seems to drive fine, pulls hard.

 

Has 264/8.1 HKS cams (not installed by me).

 

Video of the noise.

 

http://www.youtube.com/watch?v=P5iEIknu8-c

http://www.youtube.com/watch?v=jMJBT5LI6hQ

 

First video today, second video when I first got it started after it got warm.

 

I'm stumped. Cam bearings?

Edited November 13, 2013 by B.L.Z.BUB

[ke70dave]

You could remove the camshafts and check all the bits that it rotates on. And also check your valve clearances.

 

sticky valve failing to close and the piston slamming it up?:S

 

sounds freaking nasty.

[B.L.Z.BUB]

I found this thread : http://www.toymods.org.au/forums/tech-conversions/50521-help-broken-4age-2.html

 

From his videos it sounds like the same noise, so I'll drop the box and check the flywheel bolts are tight.

All the clearances checked out plus the noise wasnt there when it was in the MR2. Mind you I don't know if it got to operating temperature.

 

Any other ideas appreciated :y:

[B.L.Z.BUB]

OK googled lots of videos of 'loose flywheels' and that seems to be the same noise.

 

Hopefully *crosses fingers*

[rian]

Next time you start it up:

 

Edited November 13, 2013 by rian

[B.L.Z.BUB]

Next time you start it up:

 

http://youtu.be/http://youtu.be/6_PLnInsh7E?t=1m32s

 

For some reason I can't see that.

[parrot]

I'm guessing it's something to do with having no legs......

[altezzaclub]

The old trick was to stick your ear onto the handle of the biggest screwdriver you owned and press the blade onto different parts of the engine. That helped pin the noise down, it cuts out all the background chatter a motor makes. There is so much noise in the video I don't know which one you're worried about!

 

Loose flywheels should be pretty rare, and they should stop making a noise if you press the clutch down.

 

Did it backfired badly before the noise? We had fuel fumes in the crankcase blow up one day and it bent the splash guard inside the tappet cover down onto a cam lobe, making a terrible knocking sound every time that lobe came around. Has a tappet shim jumped out? Can you take the top cambelt cover off and run it with a timing light on to see if the noise synchronieses with a cam in a certain place.

 

It weill be interesting to see what does cause it.

[B.L.Z.BUB]

I did the screwdriver trick but it seems to be coming from everywhere.

 

Might be rare but it was my first flywheel and I only did them with a socket set, no torque wrench or loctite

[altezzaclub]

Might be rare but it was my first flywheel and I only did them with a socket set, no torque wrench or loctite

 

oooohh..... I see !

 

50ft.lb or so I think they should be, same as a head bolt.

[Sznaps]

fly with loose screws will cut them in no time so if these were loose screws they would be cut by now I think.

[B.L.Z.BUB]

fly with loose screws will cut them in no time so if these were loose screws they would be cut by now I think.

 

Ill pull the starter motor out and see if there is any movement.

[B.L.Z.BUB]

Starter off, definitely some movement, not much but I can make it make a slight knocking noise. I'd say at RPM it'd be louder.

[B.L.Z.BUB]

http://www.youtube.com/watch?v=4NcRVML4SlM

I can turn all 8 bolts by hand. Lucky all 8 bolts are in one piece.


Mental note, do flywheel bolts up tighter.

Edited November 14, 2013 by B.L.Z.BUB

[Mechanical Sympathy]

Scary. I always wondered if I hadn't torqued up flywheel bolts properly would they let go without warning. So I check them and re-check them triple-time...

 

Good to know there's a rumble warning!

 

So now you'll have a cheap/spare SC12 for sale?!