Another 86 worn timing chain "Rattling".

[nene]

I am another owner hearing the "slapping/rattling" of something that I always thought were the "tight/loose" valves, which over time adjusting them over and over realized that such was not the case. The rattling is more present when quickly accelerating, but now is becoming worse as I can hear it when driving, so I decided in opening up the chain boxes and below is what I found.

Video here: https://youtu.be/D9QhFDe_ync


I have read many similar threads here, which I will use to guide me in replacing the chains while the engine is in the car, but suggestions are always welcome.


Serge

[Trackrash]

Do your tensioners pass this test? There should be no sponginess. They should be firm.

[Jeff Higgins]

I see nothing unusual about how far those tensioners are extended. Most I've seen stick about that far out.

It is extremely unusual for the timing chains to stretch or wear. And, as far as I know, it's impossible to change them without splitting the cases.

While uncommon, pressure fed Carrera tensioners do fail. I would suspect they are the real culprit here. Does your car have the double bushing idler arms? I believe all 3.2's have them, but I cannot remember. If not, the old style single bushing idler arms are what are believed to be the cause of chain tensioner failures. They tend to bind, leading to that failure.

[john walker's workshop]

Did you check the left chain for slop over the ramp and below the idler? Could be just a collapsed tensioner.

[nene]

Originally Posted by nene

I am another owner hearing the "slapping/rattling" of something that I always thought were the "tight/loose" valves, which over time adjusting them over and over realized that such was not the case. The rattling is more present when quickly accelerating, but now is becoming worse as I can hear it when driving, so I decided in opening up the chain boxes and below is what I found.

Video here: https://youtu.be/D9QhFDe_ync


I have read many similar threads here, which I will use to guide me in replacing the chains while the engine is in the car, but suggestions are always welcome.


Serge

Gordon,

Using a large screwdriver to depress per the image you show is difficult and not spongy. How can I depress the right one?

[nene]

Here is a video of the slop on both sides of the chains.

https://youtu.be/MCieup0EV7g

https://youtu.be/JGLJLtck3DM

[nene]

Originally Posted by john walker's workshop

Did you check the left chain for slop over the ramp and below the idler? Could be just a collapsed tensioner.

Wouldn't a collapsed tensioner be flat or have a spongy feeling?

[dannobee]

Originally Posted by Jeff Higgins

And, as far as I know, it's impossible to change them without splitting the cases.

Did quite a few chain replacements without splitting the case back in the day.

The chains with the master link facilitate replacing timing chains while in the car. You would carefully grind the retaining pins off of one of the original links to split the chain, then install the new chain at the end of the old chain, then carefully start feeding the new chain in while turning the crankshaft (make sure that the cam isn't in a position to bend the valves). After the new chain has been threaded through, take off the old chain and install the master link to connect the two halves of the new chain.

Here's the Pelican method.
https://www.pelicanparts.com/techarticles/911_carrera_chain_tensioners/911_chain_replacement.htm

[Trackrash]

Originally Posted by nene

Gordon,

Using a large screwdriver to depress per the image you show is difficult and not spongy. How can I depress the right one?

You could push the chain above the idler gear, but be careful not to push on the plastic guide. If it is NG you could probably push it down with your finger.

BTW, here is a new chain, never run.

[Dauner]

FYI I replaced my timing chains a couple of years ago and made a video of the entire process. I just never edited it down so I could throw it on my YouTube page. I think it’s 5 separate videos and probably 3 hours long. If I get time I’lll try to edit it down. Lots of head scratching and non-value added time. I do remember I wish I would have had a third hand. One to hold old chain coming out of case, one to hold new chain going in to case, and one to turn crank.