3.2 race motor warm noise help

[stubble88]

I had this over in the tech area where I am getting a lot of help.

timing chain?
piston slapping?
cylinder not firing?
Wrist pin?

sound out of the exhaust is great. but it backfired that last time I tried to start it. No oil leaks. no smoke at all. change oil with no metal shavings at all.
seems like timing is off. but would that make this knocking noise? goes away with revs.
CP pistons 95mm 9.5:1
911 chips custom 91 octane

Cold start. Sounds normal. But idle is a bit higher when cooler.

https://youtube.com/shorts/xoCcPnAEDok?si=KRrkkt-5kqOdrV36

Warm. Knocking sound shows up. Idle lower when warm.

https://youtube.com/shorts/m-xKjY6AADo?si=Sk4BD-UZcyNchIK2

[r lane]

I hear a dull clatter on the second video..What happens to the noise when you blip it and on decell. Bob

[stubble88]

Smooths out. Or a bit less noisy Until idle drops down to normal warm rpm

[JoeMag]

did you try to take an automotive stethoscope to it to see if you can hear where it’s coming from? About a leak down check?

[stubble88]

Stethoscope found most noise front right timing cover. Inspected and didn’t see anything super unusual that would cause this type of noise. Valves adjusted. But found side to side play on arms. Race car that’s been sitting for over 2 years with no real driving on it. Fully rebuilt on 2008. CP Pistons added in 2013. Don’t see any metal at all on two oil drains. No smoke. Motor looks super fresh. But something inside is not right.
I’m going to tear into it before anything really bad starts to happen. Kinda excited about it but lots to learn.

[917_Langheck]

Do you somehow expect a different series of questions and answers in the forum vs the one where you originally posted?

If you are running race components in your motor as you indicated previously, then maybe you should get the motor up to race temp to see if the issue is still present. Otherwise, tear it down and mic the parts for adherence to specifications.

[stubble88]

Originally Posted by 917_Langheck

Do you somehow expect a different series of questions and answers in the forum vs the one where you originally posted?

Yes. It was recommended to me that I post here because some of y’all are not always looking at the tech section.


If you are running race components in your motor as you indicated previously, then maybe you should get the motor up to race temp to see if the issue is still present. Otherwise, tear it down and mic the parts for adherence to specifications.

Actually from the records it looks stock 3.2. CP piston 95mm 9.5:1. And Carrera cams
I’ve had it up to temp and seems to just get louder. I really don’t feel safe running it until I get into the motor. Motor is super dry and clean. So maybe I’ll get a small break on the cleaning and hopefully not too worn newer parts.

[Jim2]

Another potential thought. Maybe the engine ingested a small bit of hardware in cyl 4 or 5 (since you say the noise seems in or close to the rt chain box. With the engine at BDC 4, then 5, use a bore scope to see the piston crown

[mikedsilva]

I got seasick watching those vids. It helps to hold the camera steady and slowly pan across to the different areas you are trying to capture.

That being said, maybe pull your timing covers off and check that your tensioners have not collapsed.
Share a photo with the covers off, or a slightly more stable video

[Oldskl60]

Slim chance but an easy check, is the noise still there with the fan belt off?

[Oldskl60]

Originally Posted by mikedsilva

I got seasick watching those vids. It helps to hold the camera steady and slowly pan across to the different areas you are trying to capture.

That being said, maybe pull your timing covers off and check that your tensioners have not collapsed.
Share a photo with the covers off, or a slightly more stable video

We aren't all academy nominees like you mate, haha

[proporsche]

Mike the video on technical -what was the reason for it..Not just to look on the oil right?There is a scraping sound in it...
Ivan

[pocv0]

I think it has to be timing chain related. It could be the chain guides are misaligned , the sprocket bushing is failing, or missing spacer , or an incorrect spacer between the idler sprocket and housing . Last , tensioner failure. JMO

[stubble88]

[stubble88]

[stownsen914]

Never mind, I mixed this thread up with another one.

[dannobee]

Sounds like a tensioner failed. Which ones does it have?

[stubble88]

Originally Posted by dannobee

Sounds like a tensioner failed. Which ones does it have?

Tensioners are fine.

[pocv0]

wow, looks like the pistons are toast, timing chain gears, chains and sprockets as well. Cylinders scored?

[LukasM]

That doesn't look very good mate, sorry about your bad luck!

Any idea yet what happened yet? Was this an oiling issue or how did the piston skirts get scuffed up this way? Debris in the timing chain area?