kctrading , 6 Minutes Ago
Member
Timing chain rattle just above idle
Engine rattle just above idle. it's steady but erratic in sound...

I pulled the top intake and drivers side valve cover all roller rockers seem ok (stock ratio) but that's not where the noise is coming from...had my wife move throttle when under vehicle... can really hear it rattle when screwdriver is held up to the cover. Guy said he's been driving it like this for a while.

Makes the same noise with the belt removed.

There is no squealing noises so the cam sensor can be ruled out

Long block has about 30K per orginal owner...but he got it on eBay :/

Truck runs good. No rattle at idle. rattles pretty loud from 1200 to 2500 rpms. can hear it a little from inside when taking off lightly. After that you can't hear it in upper gears

 

I'll upload an sound file tomorrow

 

Does starter motor sound "tight", judgment call of course, they can rattle a bit if gear drive is loose, try a wooden stick on starter with engine running, same as using the screwdriver on valve cover, except safer around 12volt cables, lol

Warm up engine
Disable one spark plug at a time and start engine
See if rattle goes away and with which cylinder disabled from firing, if rattle noise does go away then could be wrist pin or piston slap making the noise

 

Here's what found and checked today...

Starter is tight and per my grounded pry bar is not the issue.

I also checked the cam sensor on the back passenger side if the eng. it's quiet too

I checked to see if shorting out each cylinder made a difference... no difference.

Also applying the clutch did not either

I also checked the three cats for ceramic rattles of its media but could not get any rattle when hitting them with a plastic mallet.

Funny I can really hear at the TBI unit but not so much on the aluminum intake.

I did record the sound on my phone as best I could... you can hear it but not as clearly in person... but it gives you an idea of the rattles inconsistencies...at the end you can hear the normal eng noise for a second.

I'm going to buy a mechanics stethoscope and try to pin point it better.

Remember the original owner has been driving it for quite a while like this... not getting worse or better. Block has 30K on it. Machined flywheel and new clutch kit at 30k too.

 

Found the noise!

 

And.............................

 

Sorry, had to shorten the video... see above mp4

 

So what do you guys think?

Single true roller Cloyes timing set or stock?

It does have a lot of mods per previous post...but I'm 65 and drive it mostly normally.

 

Ok, maybe not just the timing chain.... cam thrust plate has one broken bolt and the other one is missing...that was most likely the noise... going to drill out the broken bolt and fit it over do the smooth side hits the cam.... there is like 10/1000 free clearance so the timing gear is what's been holding the cam in.
this how it was riding on the back of the timing gear...I don't see any damage to the cam surface... goibg to flip it over and reuse it


Anyone seen this happen before? Beware of eBay short blocks! Where he got this one

 

Chain was hitting cover too...




Loctight in place with 8.8 grade allen bolts

 

kctrading , 1 Minute Ago
Member
What would cause both cam thrust plate bolts to snap the heads off?

I used a magnet to fish the other 3 pieces out of the oil pan

Over/under torqued?
Lack of washer or thread lock?
Under rated bolts?... says 2 on head
See pic