Chain tensioner noise

[classicsdubai]

So i was having problems with the car. A lot of sound coming from cam chain housing. Opened it up and saw and think thatthe hydraulic lifter is not fully lifted because the sprocket is moving freely as shown in the video. However when i used to accelerate the engine the sound would diminsih or mayb i just cant hear it because of the engine noise. But over all it is very loud on idle. Is it the chain tensioner gone bad or the oil feed isnt sufficient? Any tests you could recommend?

https://m.youtube.com/watch?feature=youtu.be&v=d7PpFdnbrpU

[T77911S]

once again

chain tensioner.

they will get quiet when you drive.
I drove 250 miles with a bad one, loud at idle, sounds like a really bad exhaust leak but it gets quiet at speed,

(I edited it to be nice(r))

[classicsdubai]

Originally Posted by T77911S

once again

chain tensioner.

they will get quiet when you drive.
I drove 250 miles with a bad one, loud at idle, sounds like a really bad exhaust leak but it gets quiet at speed,

(I edited it to be nice(r))

As you can see the sprocket is slipping on the tensioner. Isnt it aupposed to be tight? And not moving? Is there any test i can do? Maybe the oil feed lines? Or need to replace the tensioner. Because i just think the sound isnt going to go away as long as the sprocket is moving.

[yelcab1]

That seems to be very loose. Your tensioner is also of the older non-hydraulic type, which has collapsed. You can rebuild those, or replace those, or upgrade to hydraulics (waste of money). Don't procrastinate, just change them.

[classicsdubai]

Originally Posted by yelcab1

That seems to be very loose. Your tensioner is also of the older non-hydraulic type, which has collapsed. You can rebuild those, or replace those, or upgrade to hydraulics (waste of money). Don't procrastinate, just change them.

Thank you for your feedback. I will change them then. And will post some pictures as i hope there is no damage internally. Because the hydraulic lifter is slightly low just scraping the arm on the top. I was expecting a collapse to be all the way down. For now i just hope nothing else has gone wrong.

[RSTarga]

Don't start it until fixed!

[classicsdubai]

So was doing more inspection and the tensioner is fine as i measured the length of the hydraulic lifter compared to the lifter. However, the arm which im fiddling with in the video is not centred onto the lifter. Also there i feel the chain is a little loose as it doesnt have much tension causing the arm to extend upwards and moving it close to the casing. Please see the video
https://youtu.be/Rka-Jo6TH0A

[boyt911sc]

Classicsdubai,

Looking at the video, it looks like the idler gear lever is touching the chain housing already (?). If this is the case, the timing chains are already stretched too much. Do a compression test to the chain tensioners and see if they are still stiff during compression. There is a likely hood that the root cause of the noise is the contact between the idler arm/s and the chain housing/s. Re-check your cam timing before running the motor and so with the valve timing. If the timing chains are capable of jumping off the timing gear, it could produce some serious damage to your motor. Do not take unnecessary risk. Check and confirm.

Tony

[tharbert]

I don't know what year/type engine you have and I'm just an enthusiast, not a guru of any sort...

There are two different idler sprocket supports. The biggest (only?) difference is the width of the base that pivots on the shaft. Older supports have a narrower base.

I don't think that movement/play is right and hopefully someone with a lot more experience will help clear this up. If you have a mismatch of parts, you may need either the shim (Part #930-105-513-00-M105) to accompany a narrower support or the upgraded, wider support.

You can zip tie your chain in place to make sure it doesn't lose timing and remove that tensioner. The piston should be very stiff to operate. If you can compress it with your hand, it has failed. They can be rebuilt (hydraulic, non-pressure fed)...or upgraded.

['76 911S 3.0]

Looks like the chain is stretched

[classicsdubai]

https://youtu.be/eO6iAb5E820

So here is another video i made of the chain does the movement in the chain seem pretty loose? I do not know how to do a compression test on the chains.

[boyt911sc]

Originally Posted by classicsdubai

https://youtu.be/eO6iAb5E820

So here is another video i made of the chain does the movement in the chain seem pretty loose? I do not know how to do a compression test on the chains.

Dubai,

The compression test is done on the hydraulic tensioners and not on the chain. Get a big or long screw driver and pry between the idler lever arm and hydraulic plunger. A good hydraulic tensioner would offer great resistance against compression. A bad unit would be easy to compress. Remove the hydraulic tensioner/s and bench test it too. This is a very simple test and could identify a bad or good unit. Keep us posted.

Tony

[bigel]

Anyone have a video (with audio) of an engine at idle with such an issue? I have a 'tic-tic-tic' type noise that I attribute to loose rocker gapping (better loose than tight is what I am told), but you all have me worried now.



Interested in some opinions here on who the video above sounds to those with a decerning ear.

Some background, I just (September) finished a full tear-down and rebuild and when I reinstalled the tensioners, and after turning the engine manually serveral times; cam timing, etc., both sides were tight.

Don't intend to highjack the thread, but am interested in the same diagnosis...

[T77911S]

the tensioner is very very loud.

if you need a video, search the OP, he likes making videos.

[tharbert]

I believe you have three issues. 1)Primarily, the timing chain has stretched beyond to ability of the tensioner to control. There is only one fix: replace chain. 2) Your tensioner support/sprocket moves on the shaft. I might be wrong but it looks like you need either the wider based support or a bushing. The wider based support is the optimal fix, the bushing, more economical. 3) Your tensioner may or may not have failed. You have to test it as Tony described. It may have enough resistance to extend the piston but not absorb the chain slack. You would test it by pushing the piston down into the tensioner. If you can do that easily, it has failed.

Pelican has a super kit that has all the parts grouped together to make this repair. You would typically replace the chain, tensioners, tensioner support and chain ramps.

A note of caution: What you have videoed appears to me to represent some pretty severe wear in the valve train. And, again I might be wrong but, it appears to me the last person to assemble the left tensioner assembly did it incorrectly. Does the other side move like that as well? I think you should probably gather some more information. Try to determine what's been done to the engine in the past. Any documentation? Have a cylinder leak down test performed and inspect the head studs. You could spend $2k to fix the timing chain only to find out you have bad heads or pulled studs, requiring a top end job at a minimum or a complete overhaul to fix head studs: case split and extensive machine work done.

It might be the perfect time to find a 3.0! Good luck.!

[classicsdubai]

Originally Posted by boyt911sc

Dubai,

The compression test is done on the hydraulic tensioners and not on the chain. Get a big or long screw driver and pry between the idler lever arm and hydraulic plunger. A good hydraulic tensioner would offer great resistance against compression. A bad unit would be easy to compress. Remove the hydraulic tensioner/s and bench test it too. This is a very simple test and could identify a bad or good unit. Keep us posted.

Tony

So took off the tensioner and here is the video. There is some resistance but can be pushed in with the finger. Please see the video. What do u think if it is fine?

https://youtu.be/1AlrZBRPL5A

[356911930]

It looks like that tensioner needs to be replaced or rebuilt. A good tensioner requires a LOT of mechanical force to move. you might as well replace the chain tensioners and the chains. If your car has high mileage you might want to replace the chain ramps too.

Best of luck,


Rahl