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Ok I was waiting for somebody to throw out a "this is normal" but since nobody else has.....(and unless I'm not hearing something else).......I believe we're talking normal here...
I've listened to hundreds (did I just admit that?) of cold starts on 996's and 997's on BAT and many, many, many I recall have sounded exactly like yours.
I think mine does too?....though I'm never behind mine when I start up so I can't say 100% but I've also got gundo hack on mine so might make some different than stock noises by the hack alone.
Anyway.....I didn't hear anything unusual in yours (I actually love the burble which is why I identified it as totally normal when I heard it) And if *you've* got any problems, I can tell you there are a great many that suffer from the same condition being sold daily on BAT.
#2 -------- (almost forgot to comment on this) ------- When you say you see "smoke" after startup, I'd be willing to bet you're identifying water vapor shortly after initial startup which happens on cold starts as the exhaust is not yet up to temp but rapidly gets there burning off any water vapor showing as "white" in your exhaust pipes as it comes out. (It shortly goes away after engine temps start to rapidly increase)
#3 ------ And as for fuel-smell, I think this gets blown out of proportion in cars in general. Heck, we have a brand-spankin' new Tacoma at work with one of the kings of Toyota motors (3RZ-FE) and can't get any more fuel-efficient than brand-spankin' new and every time we start that truck up in our bay to start the day for the last several months, it just fills the warehouse with fuel-smell. (As does my wife's Venza and my daughter's Accord at home when I back them in)
Our cars burn fuel......it's gonna smell a little like fuel. I'd be FAR more concerned if things smelled like oil....(a VERY distinct smell)....than fuel.
My armchair opinion is your 997 is working normally! (And I'll be the first one to admit I'm paranoid about every quirk of my 997. I expect my motor to blow like a grenade every day, but I know my thinking is really just Porsche Paranoia)
Definitely giving me information to digest. Being new to the Porsche ownership and having perused so much negative information on the internet prior to purchase that I too am a bit paranoid.
Thank you.
Doug
thanks for the suggestion on what works for you.
Doug
well as an update, I have drained the oils and examined the oil filter. Fortunately the oil looked good — no foam and appeared as used oil looks. I opened the oil filter and it too was clean (with the exception of three SMALL black particles (pic attached). So I don’t think I have bore scoring, IMS issues, or timing chain guide deterioration.
thoughts??
The black plastic is tensioner paddle guide material. Some have black plastic and others dark brown plastic. With a cold start noise that goes away and the pieces of black plastic, I'd change your 3 tensioners ASAP.
well as an update, I have drained the oils and examined the oil filter. Fortunately the oil looked good — no foam and appeared as used oil looks. I opened the oil filter and it too was clean (with the exception of three SMALL black particles (pic attached). So I don’t think I have bore scoring, IMS issues, or timing chain guide deterioration.
thoughts??
I also put Sea Foam in the fuel tank to start cleaning injectors. Tank is full of fuel so may take a couple times to see if we have any difference of fuel smell and/or exhaust cracking/clunking.
thanks to all for input. Let’s hope we determined the cause.
Just listened to the video and there is no timing chain noise in that startup video. The odd gurgling noise actually sounds like some loose baffles in the muffler or cats rattling around. With the car off, bang on the mufflers and cats with the heel of your hand or a mallet. You hear anything that sounds like rattling similar to that. The particles are certainly timing chain paddle material though.
My best guess from my research is one or more chain tensioners or muffler/exhaust/cat.
Would the plastic bits from the chain guides be visible in the oil or just the filter? I ask because when I last changed the oil I only looked for metal sparkles in the filter before tossing but still have the old oil.
Since I can't yet confirm chain guides wearing, I'm tempted to take the exhaust off and re-test. It would be very hard to hear the difference over the open headers.
Last edited by Atomic Rooster; 05-07-2024 at 12:47 PM.
Did you try whacking the catalytic converters and other muffler parts with a rubber hammer? With the car running and making that noise, press your foot onto the exhaust tips and listen for change?
05-05-2024, 11:59 AM
