996 Engine noise/tick....new short-block

https://www.youtube.com/watch?v=YF7s...ature=youtu.be Hey guys, I have attached a link to a you tube vireo regarding a noise that has developed in my 2002 911 Carrera 3.6L. A bit of back story.....I purchased the vehicle off a customer of mine with a blown engine (engine had broken timing chain and bent two valves). I pulled the engine and acquired a factory reconditioned short block from Porsche dealer.....had the heads checked/redone at machine shop with new valves and all new guides etc......I installed all new tensioners, new sprockets/actuators.....all new exhaust and intake lifters installed......assembled to spec with necessary special tools. After assembly vehicle fired up and ran great....pulls hard and no signs of oil consumption......after about 2500 kms of driving I started to notice a ticking sound. noise is not so much present on cold start but after warming up it becomes apparent....it is intermittent at idle but can be heard when reeving up the engine. Removing the belt and noise is still present so not an accessory noise. I still need to have someone up in the vehicle and rev it while I try to pinpoint it with a stethoscope to further try and locate the noise.....but was curious if anyone has had similar noise/symptoms....... I know there is a rash of bore scoring issues but would be shocked if that were the case with only 2500 kms on reconditioned short block..... If possibly Jake Rabbi could chime in here on his thoughts that would be great......I know I have to do some deeper investigation.....but just curious on thoughts here. Cheers, Russell

Mine makes this noise also, if you are referring to the occasional sharp tick sound when revving. I believe it is the cats expanding/contracting with the change in exhaust temp and flow.

I didn't hear anything except someone free reving an engine that does not to be reved unloaded. What kind of rpm were you hitting? Just my uneducated opinion, of course.

That is not what I would consider a normal sound, I would stop reving the crap out of it and get it checked ASAP before more damage is done. Others who have posted this sounds normal, please have yours checked as well.

I listened to it again with head phone this time. I do hear the ticking of the cats but also another high frequency, ticking noise that doesn�t sound healthy. As far as revving the engine, it doesn�t sound like it was rev�d past 4K. Not sure why people are all excited about that.

It's definitely not a normal sound....I know it may be hard to hear but there is a cyclical noise. Regarding the revs i was holding it at around 1000-1200 rpm and blipped the throttle towards the end in order to best replicate the sound.....rpms went to about 2800-3000 rpm..... Just looking for some good feedback regarding noise.....I will dig deeper into it....

I agree, something does not sound right. I'd stop running it. Did you just fire it up after install or did you crank it a few times first to bring up oil pressure?

Ya I'm not driving it now.....before firing up engine for first time I prelubed engine with a pressurised oil priming system borrowed from machine shop...oil pressure built up.instantly on startup so shouldn't have been an issue..

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Did you have the intake seats replaced? They are known to fail. Also, were the lifter carriers replaced? Were the injectors replaced at time of installation. A bad injector can wipe out a new engine in no time. We had to replace a factory crate engine that lasted 10 hours of track time before it scored a bore. The new engines are not immune to prior modes of failure as zero improvements have been made to their design.

Charles, I really appreciate you taking time aside and giving me some feedback here on your past experiences with these engine. The heads were sent out to machine shop and reworked but valve seats were not something on the list.....also the carriers were checked and reused..... it's quite possible that either of these have presented an issue now.....in your opinion would a bad carrier present this kind of noise....I could see a failing seat causing a noise like this...... Injectors were sent out and cleaned/flow tested at injection rebuild shop....all checked out ok........(I could see in theory if one were bad/leaking I could see how it could gas wash/wipe out a cylinder). In past experience would not a scored bore be nosier when cold on these engines..... in my case noise is mostly only present after about 3-4 mins after cold start....once fully warm noise is present. Thanks again for your input. i am going to try and dig deeper this weekend.....will try to pinpoint particular cylinder/location of noise with stethoscope. Also may pull lower pan to try and boroscope cylinder bores...also pull plugs to inspect bore from top side..... I here ya regarding factory rebuilds/crate engines.....you would assume everything should be perfect on a reman from Porsche....but like you say noting has really been done to resolve the previous potential known issues regarding bores etc.... Cheers, Russell

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There is a bulletin that the lifter carrier must be replaced when replacing the lifters. It's possible that is the source of the noise, but scoping the bores to be sure isn't a bad idea. I can't comment on what noise a loose seat would make - cylinder heads are something I leave to the cylinder head pros.

For cylinder head info contact Len Hoffman at https://newsite.hamheads.com/ He is a specialist in Porsche heads and is the guy JR and others use. Alsolutely top notch advice and work without a lot of B.S.

When you say you have a new exhaust, does that include new Cats? I hate to keep saying this but i have heard so many Cats and DMF;s making knocking and strange noises I Can't help it. Check the oil filter for debris then listen to Cats and DMF area first.

Thanks everyone for the replies.....going to take a close look into it tomorrow. Charles, I have seen some of the info regarding the lifter carriers...hopefully me not replacing them will not come back to bite me...... Coopduc, thanks for the lead regrading heads....had a quick poke around on the link.....looks like he is definitely the man regarding Porsche heads! I will dig a bit deeper and pick his brain if I hit a wall on this. Porschetech3, I have replaced the exhaust valves and guides....but the exhaust system is all original from what i pulled off (previous owner stated its equipped with quick silver muffler system). I know the video at idle comes through like a exhaust that cools/expands and ticks.....but when accelerated it definitely sounds more mechanical/internal. Also regarding dual mass flywheel......clutch in or clutch out or even slight pedal pressure doesn't change the noise......but of course i wont rule any of these out before digging deeper and appreciate your thoughts. Also pulled filter and cut open....no signs of any metal/debris present.... Russell

You need to use a mechanical stethoscope to poke around the engine, cats and mufflers carefully. Such obvious noise should be easy to track down.

Ticking? This is ticking: You Tube

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Tick? That's not a tick! This is a tick!(said using the voice of Crocodile Dundee): You Tube

That's not tick... That's a "CLUCK" !!!

Damn, those are definitely more pronounced!!! Update on mine....seems like the more I drive it the ticking has subsided.....possibly was just a lazy lifter that needed to be bled out with some driving....will monitor it for now!

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It's been a year and is getting better? The Porsche Gods are fixing it for you !!! Definitely not bore scoring......

I will cheers to that!