Name that sound

[psychogecko]

So driving home, actually turning down my street 100 yards from the house this started. I have been looking for an excuse to drop the motor (not really), but I figure I would through a little game out to everyone...First one to guess what is causing this sound wins. Sorry I will have nothing to offer after flipping the bill to repair...but you can show everyone how smart you are and a thank you from me.

Background. 1975 2.7

youtube link

https://www.youtube.com/watch?v=3YRB-GYl_-s&feature=youtu.be


Thanks.

[RedCoupe]

Before I would start tearing into the engine, I would for sure pull the timing chain covers and see if the noise isn't a collapsed tensioner. BTW, has your engine had upgraded or rebuilt tensioners installed at some point, or are they still the originals? Mileage?

[Len 911]

I'll tell you what causes that sound, SOMETHING WRONG ....Winner Winner

[psychogecko]

Answers. Yes she has the upgraded tensioner (not sure when they were upgraded), mileage 98K....

Thanks Len911...yes...some-ting- wong.

I will check tensioner. Thanks Coupe. Anyone else? Someone here on this forum has heard that sound before.

[RedCoupe]

Sorry, Psychogecko, but listening to your YouTube, isn't quite like being there with your head close to the engine! When one my own starts making some wierd noises, I usually get out the old rubber hose and with one end next to an ear, I move it around the engine until I can zone in on where the sound is coming from. But, in this case, the sound is sufficiently nasty that I wouldn't want to start it again until I figured out what was going on. I'd probably start by pulling the timing chain covers, and if everything's fine there, then I'd pull the valve covers. Lots of opportunity for mischief in the valve gear, so I'd carefully look at every valve and rocker arm. You may, indeed, wind up dropping the engine, but I'd definitely do some investigation while the engine's still in the car.

[Lapkritis]

Sounds like rocker arm slapping around to me...broken elephants foot perhaps. I would start with taking the valve covers off.

[Lapkritis]

Just watched it again and there's two distinct tapping sources. If the rockers and timing for cams all check out then I wouldn't start it again in case it's a rod bearing... hate to score the crank with continued operation.

[trials935]

Sparkplug loose or blown out? Ken

[Sboxin]

I have heard a sound like that twice - - - and was able to save the engines by checking
the chain tensioners -- a '72 2.4L with 50K miles and an '84 3.2L race built stock spec
race engine.

Your condition may not be this failure - but worth checking along with the rockers.
IMHO would not start this engine again . . .

Regards,

[RedCoupe]

So Psychogecko, it's a three day weekend! Going to get that 911 up on the jackstands and start pulling timing chain or valve covers off? I hope so, cause we're all on the edge of our chairs wondering what the real problem is! Send us lots of pictures of whatever you find!

[psychogecko]

Thanks for all of the support guys. It is a 3 day weekend and I intend to lift it up and get dirty. I will take pictures and start with the chain tensioners and then move on to the valve covers...if only I can excuse myself from the visiting in-laws...lol without going to the dog house. Still have to be good if this project turns out to be more expensive than the chain or valves.

I will have time this weekend and post progress pictures.

[mreid]

Good luck, PG, sounds like a rocker to me (more AC/DC than van halen).

[psychogecko]

Well...the chain is good, rotating the motor has some binding issues (free to turn up to a point but then hard to turn over a certain point then free again). I was able to peak in the # 6 and see some shavings of something in there. I cannot quite get the camera to focus in there. Either way 46 mm crows foot and cam removal tool here I come. Let the FUN (expenses) begin.