3.2 race motor warm noise help
 

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

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

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

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?

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.

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.

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.

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

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 ;)

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

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

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

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

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

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

Tensioners are fine.

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

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?

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I'm guessing the wrist pin on one was floating due to a missing circlip? Just one ? So maybe you just need one piston and cylinder? Or are the other cylinders scored as well ? Just curious.

or maybe a broken ring...that must be it. The galling is 90 degrees from the wrist pin location.

yup it does not look good....it got hot..see those marks on the piston...wrist pin was very easy to take out,right? Yup those chain gears look bad too but that was not your noise..i have seen worse...

Ivan

those spots on the inside of the cylinder and one pistons really looks like water spots(corrosion) and being polished out...right at your index finger..

Ivan

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Doubt your supposed to add goo to the piston base gaskets.
Other pic is the idler arm bushings

yup some mechanics use this stuff on the copper ,i do not...but it almost looks like the engine was starving for oil

Some recommend non-hardening sealant like curil T for cyl base gaskets. I’m probably going to give that a try for my motor that’s about to go together.

Question about what to look for on cam chain gears for wear. I’d understood that wear in the U is a key thing to look for, along with thinning of the gear teeth. And of course any chips or other damage. What else?

It's common and sometimes actually recommended to use a very thin layer of Curil T.

I have pulled apart an engine where they used the grey 1104.. it's not recommended but that engine performed fine and it didn't cause issues.

Using Curil T, allows some time to bolt on the heads and torque down. But if using the grey stuff (or anything that is NOT non-hardening) I would imagine you'd potentially have issues if it cured before you got your heads on and torqued.

Man, it looks pretty whipped all around. You have my sympathy. I’d want to find a smoking gun to feel good about avoiding it the next time.

#5 rod bearing

http://forums.pelicanparts.com/uploa...1721415643.jpg

pretty bad...where o rings on the oil pump in correct place---and are they green?
The other rod bearings same or ok?Is there any discoloration on the bottom of the rod-like it got hot?
Ivan

Crank looks good. Past fingernail test.
One of the rod bolts did not feel torqued compared to the other.
I havnt split the case test. Just looking at #5.


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at least a little good news..

Took my heads pistons and cylinders to Walt at Competition Engineering. Walt is amazing. Super nice guy. Long drive. I didn’t look to well because he found a broken exhaust valve guide. Thank god it was on the exhaust side. And I’m glad I started the teardown which exposed this. So the heads will get redone. He said my pistons and cylinders looked great. So better in person. He said noise had to be the tensioners and to just replace them. This is consistent with any of the expert porsche mechanics. I probably will not split the case seeing this motor still looks new and has very low miles/hours. Walt didn’t think it was necessary. http://forums.pelicanparts.com/uploa...1721510542.jpg

You can trust Walt. I would not split the case either, unless it is leaking and you want to reseal it. Otherwise you risk getting crap into the oil passages, which will then embed in the bearing shells.

That #5 rod bearing looks good to me. Yes, there is some embedding of a soft metal (almost certainly aluminum bits), but if it passes the plastigage test, I would put it back in as-is. It has already bedded to the crank journal, so don't mess with it! Likewise for the other rod bearings; put them back into the same place and do NOT replace them.

Some vertical marking in the cylinders and on the piston skirts is normal. I would not mess with those either. At most, break the glaze, but put it back together with the same pistons/rings in the same cylinders. Since you say this is a race motor, you will be pulling it apart at regular intervals anyway, so don't worry about minor wear. And expect more wear, because you are flogging it.

You are consistent with all the other pros. I only removed #5 rod. I might remove #2 rod to examine
Lots of good news today. Even finding a broken valve guide eases my mind of needing to tear into the top end.

Those bearings look fine. Make sure there's some "crush" left when you reinstall them, and check the clearances with plastigage if you don't have micrometers and a dial bore gauge.

Good news!
What did Walt say about your cam gears? I ask for a selfish reason, as I'm about to assemble my own motor and wondered about some of the comments you got earlier in the thread.