M96 whine

I bought a 2000 C2 cab a couple weeks ago, it's been a great car so far but man does it WHINE at lower rpms. I thought maybe I had a bad idler pulley but the whine is definitely from the engine, not the belt, not the trans. I took it to my independent guy who thought, incredibly, it sounded normal. I went through a bunch of BAT seller videos and he seems to be right, pretty much all the 5 chain engines whine like crazy at lower rpms. Some louder than others, probably depending on the video, cab vs coupe, etc. They all whine though. Here's an example at 0:45 (BAT, not my car): You Tube Questions for people who know these cars: 1) What makes the whine? It's specific to the 5 chain engines - both the early 996 and 986 sound the same, the 3 chain engines don't whine like this. Is it Variocam? If so, why did my 968 (also with first-gen Variocam, down to the same nylon pads) not make this whine? 2) Any ideas if freeflowing cats or maybe a lowered car makes the whine louder? Thinking my car on coilovers has increased resonance from the pavement. 3) My Variocam pads are probably worn, would think this could contribute. Listening to BAT videos, I don't hear much difference between low and higher mileage cars though. Anyone notice a quieter whine after changing their Variocam pads?

I have a Variocam + 3 chain motor and it whines like a teenager. The video you posted sounds normal to me. The noise comes from the timing chains. The primary chain from the IMS to head is pretty long and there are two of them. This adds up to substantial whine(I suspect the tensioners keep them quite tight to avoid cam timing issues). Drive it. Or, but Durametric and check the cam deviations.

Thanks, guess the sound is just characteristic. Kind of thinking the variocam pads themselves don�t contribute that much to the whine, given that my 968 didn�t whine at all and had variocam, plus the air cooled cars also had a whine but no pads. And your 3 chain car, also. Previous owner changed I think three chain tensioners so that could be why my car seems a little loud, but again I have no experience with 996s, so who knows. My indy guy wasn�t worried at all. My bank 1 cam deviation is out of spec but I�m not ready to drop the engine yet just to replace the variocam pads. Car runs great, idle is maybe a tad rough but not too bad, no CELs or codes. If that changes it will get done sooner, but for what I have into the car I�m just going to monitor it for now.

My 2000 C2 did it too. You just have to live with it, but I didn't love that sound. Some don't whine as much, some do. Replacing the variocam pads will most likely not fix the whine. I moved to a Turbo which doesn't whine.

Always tough to tell from a video. If its not the chains or trans, you can always pop the engine lid and check/listen for an SAI whine. I have had a low muffled whines and loud whines. Once the engine and cats warm up it goes away when the SAI isn't needed. It's louder in cold weather months than warm.

That's the signature "sewing machine" sound..The dual roller chains are the root contributor...The later "hyvo" chains are a bit quieter...

I actually like the sound. When I had an 88 targa, the sewing machine sound was mostly from the solid lifters combined with the air fan. My 996 sounds a little like this too. It�s all just part of the experience.

Circling back on this thread with some answers for posterity. 5 chain engines whine way more than 3 chain, it�s a characteristic of the design. After a while listening to YouTube and BAT videos you can tell if it�s 5 or 3 chain strictly based on the idle note. ALL 5 chain engines whine to a greater or lesser extent, I could not find a single 99-01 example on BAT with a driving video that didn�t exhibit this. High flow cats and some aftermarket exhausts can increase the volume of the whine, but it depends on the car and aftermarket manufacturer. I have no way to prove this, but I have a theory that Porsche designed the stock exhaust specifically to counteract the chain whine in the cabin. Here�s one really clear example (not my car): You Tube Replacing variocam pads does not appear to change the volume of the whine. I found one BAT video with just-changed pads that had the same characteristic whine as the other cars. Same thing with low-mileage cars, I found a 5k mile car on BAT that had the same whine. i couldn�t find any examples on any of the forums of increased whine correlating with variocam pad condition or any kind of engine failure. This excludes the whines that are due to accessories or water pump, obviously that�s a different story. Bearing noise is distinct and doesn�t cause or contribute to the whine. So my conclusion is that the M96 whine is a completely benign phenomenon. It�s an inherent and unique feature of the 99-01 M96 engines.

Not to mention there is a high pitched whine that comes from the SAI when it's failing. But it will go away after the cats heat up. And there is a whur that will come from your powersteering when the fluid is low. A regular symphony...

I have a Fister exhaust on my car and I've never heard any whine!!!

Embrace the "Whine" !!!

Quotes source post: 19032460

As noted, it depends on the car and application. Here's an example of a 996.2 where the Fister made the whine less noticeable. (Skip to about 2 minutes). It's still there, still same pitch, just that the Fister drowns it out. This car does seem to have more whine than most 996.2s - again, the degree to which a given car does or doesn't whine is idiosyncratic. The chain whine isn't "bad," it's just characteristic for these engines. You Tube EDIT: Here's a 996.1 example with 19K miles. BAT seller states aftermarket exhaust, looks like stock in the pics so probably either Fister or Gundo hack. Driving at 4:19. Road noise drowns it out some, more prominent at the 5:00 mark at slow speeds. You Tube

Circling back to my thread - I completed an engine-out variocam pad and camshaft timing chain replacement. Big job (45 hours all-in) but it�s done. Cam deviation numbers improved: -8.5 and -4.2 before 0.34 and -1.7 after Car idles much better and the �resonant whistle� on my car at ~2600rpm is MUCH improved. The bank 1 pads were massively pitted. Pretty sure the pits were causing resonant noise in the mid-rpm range. it still whines of course but it sounds like a normal 996 now. Just wanted to share the data point.