Name That Noise

[DRACO A5OG]

Hey All,

So it's time to play "Name That Noise"





Chain Tensioner

[mca]

I think you need to use a regular video camera before you will get any feedback. It just sounds like garble.

[DRACO A5OG]

Good Idea, Here it is:

[slodave]

Jim,

Give it a little rev while videoing.

Dave

[DRACO A5OG]

You can hear it much clearly on the first few seconds. it's that rattling noise.

I am afraid it is the chain tension ramps or worse the tensioners

[slodave]

I can hear it just fine. Does it go away when you give it some revs????

[DRACO A5OG]

Yes, it does quieten down a bit when reved, but at slow increase in RPM's the noise would increase with the higher RPM's

[slodave]

You should be able to get a better idea, if you have a stethoscope or long rod that you can put against each chain box and put to your ear. Since you have hydraulic tensioners, the noise should go away temporarily if you rev the engine. Oil pressure builds and the tensioners tighten up for a moment, making the noise go away.

[DRACO A5OG]

Thanks Dave,

Question? what do you think is the most likely culprit?

Tensioner
Ramps
Sprocket

[slodave]

If the noise IS coming from one of the chain boxes, then my money is on a tensioner. I don't think a broken ramp would cause that noise and you'd know if something was wrong with one of the sprockets.

[relayswitcher]

Car starts and idles normal sounding. Rev it and the noise comes up at the let down of the rev after the chains have tightened then loosen and then the inconsistant noise. First remove any belts turning the fan. Start the engine briefly, if the noise goes away it's your fan or housing out of keel. If the noise persists, reattach the fan belt to gen. fan. My guess at this point is chain tensioner failure. Pop up the back of the car a couple a couple of feet. Place on secure jack stands of the correct weight rating and block front wheels. Have 2nd person sit in car and start it. Have them rev once as you signal with "go". Smile WavyThe noise usually sounds worse on one side than the other. Start with that side. If right rear, start at #6 then rev and listen. You'll hear lifters tapping away. If sounds normal start listening to #4 then #5. #5 will usually conduct the noise from a chain housing noise and sounds like you are getting closer. If none of the cyls has a hard metal pounding sound, most likely its tensioner failure. As you listen with stethoscope from #5 to the right housing it should get louder if it's the chain tensioner. Almost like someone taping directly at your ear through 1/8" metal. Sometimes at this angle the mystery noise with be consistant and that helps if you have no one to rev for you. I have a car with the same noise and after I opened the chain housings I found someone had placed safety collars on both the tentioner cylinders. I think that is some of what my noise is. And thank God they prevented the chains from jumping the sprockets. I already have a full 930 pressure fed set to put on the car I was saving for a 2.7 rebuid I'm doing, so this will go on my Targa's '81 3.0 engine. Hopefully this is the solve. Pistons or rods don't sound like they are bad. I've heard that kind of failure and this is not that. Your film sound was authentic and familiar. Although you submitted you clip last year I hope this little bit of shared experience helps someone out there. Relayswitcher june 1 08

[DRACO A5OG]

Whoa RelaySwitcher!

Welcome aboard Brother! Please post a pic of your baby and I have a question?

Could I replace the tensioner without dropping the engine?

[Flieger]

I believe tensioner replacement can be done with the engine in the car. surrounding sheet metal/air ducting needs to be removed. Then just take off the cam chain covers and there you go. Just don't get any big ideas while you are in there.

[rusnak]

Hey Drago, nice to see your engine.

That noise could be a chain tenstioner. Once again I have to agree with Slodave, I think he nailed it.

One thing I would check would be the alternator bushings though. You can isolate the cause with a long prybar or screwdriver too. That's what I use at first, then go to the stethoscope if it's inconclusive. You can also use a long piece of refrigerator water tubing. Isolating the noise source goes a long way to diagnosing the problem.

I think the chain tensioner would make more noise when the engine is cold, and reving it more would make more noise. The reason is that until the oil gets hot and thins, you are building back pressure, but not necessarily more oil flow. It is the oil flow that pressurizes the tensioners. I think you may have a weak tensioner. Check the tech articles for one on replacing the chain tensioner in the car. I'd be concerned about cam timing. Hey, if you organize a day to work on the car, maybe a bunch of us can get together and help you.

[DRACO A5OG]

Oh Man Rusnak,

A great idea, a Chain Tensioner Replacement Party

I have a feeling it is the tensioner but will check everything.

When I start her up, it makes a pronounced rattling noise then calms down a bit. When I rev, it disapates but when I slowly increase the RPMs it maintains the rattling noise but faster.

Oh Joy, I truly am rebuilding my baby, box by box.

[DRACO A5OG]

Question Fellas? HOW LONG CAN I DRIVE HER THIS WAY or should I not drive her until I replace the failed part?

[slodave]

You should not drive your car. If the tensioner failed and you keep driving, you will introduce the pistons to valves in a very personal way.

[rusnak]

I would try to find out where the noise is coming from first. Probably not drive until you know what it is and have a chance to inspect.

Does it make noise when the engine is warm? I generally am more concerned about noises when the engine is warm, than when cold. A cold engine can make some funky noises.

[DRACO A5OG]

Yeap, during and after a hour's drive.

[rnln]

I am in for this party. It should be interesting. Let us know when you start it

Originally Posted by DRACO A5OG

Oh Man Rusnak,

A great idea, a Chain Tensioner Replacement Party

I have a feeling it is the tensioner but will check everything.

When I start her up, it makes a pronounced rattling noise then calms down a bit. When I rev, it disapates but when I slowly increase the RPMs it maintains the rattling noise but faster.

Oh Joy, I truly am rebuilding my baby, box by box.