Merry Xmas to me- tick/knock at idle...

Drove around the block before putting my 04 C4S in the garage and heard a loud ticking from the rear of the car. I'm leaving town for the Holidays today but when I get back need a good reputable shop to take a look. I'm in Los Angeles (San Fernando Valley). Any suggestions or am I just better off going to the dealership? In the event this is an IMS failure, I'd love to find someone familiar with the upgraded LNE parts. I searched and came up with very little info... Here's a sound clip I recorded. I have since shut the car off and will not crank until someone looks at first. No engine lights, no leaks... http://www.dailypost.tv/graphics/Sound/PorscheSound.aif TIA

Temp outside? Oil type and weight? Sounds like lifters.

+1 for lifter noise...

Assuming this is a lifter issue, how difficult is this repair?

See post #2 Could be as simple as the temp and/or oil.

Take a look at this post on renntech.org: http://www.renntech.org/forums/index...6&#entry163696 JP

Might be a chain tensioner. Another local guy had a similar sound and after a flush and refill - PRESTO! - problem went away. Don't ask me how the shop did it.

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Noise doesn't sound all that bad. A car that sits unused for a long span of time (week or more though it varies based on engine internals, state/condition of oil, etc.) can develop a tick that appears upon cold start and can stay around for a few minutes at idle. A zero lash lifter can collapse and fail temporarily to pump up with oil. A chain tensioner can bleed down and again fail to pump up with oil right away. An injector can get noisy. These engines have a lot of reciprocating parts and cold an engine is just noisy. You may have been hearing something normal. How fresh is the oil? Oil with some short trips and no real hot running can really develop a load of water and unburned fuel which tends to make the oil thinner and the engine noisier upon startup. This oil tends to run out of or be forced out of areas like the zero lash adjuster and chain tensioners more readily too. Is oil the right viscosity, a fully synthetic oil, and a quality brand of oil recognized by Porsche as suitable for use in the engine? No 10w-20 discount oil in the engine I hope? An oil change might be called for. Lastly, my Porsche tech tells me that for cars that sit around with little use a Swepco oil additive (505 IIRC) can help cut down on the noise these engines make when started up. Cutting down on noise also reduces whatever wear the noise represents. (I did an analysis of this additive and it contains 200ppm of molybdenum, an anti-friction additive.) Sincerely, Macster.

Try starting then adding a little more idle for 5 seconds or so in the range of 1,200rpm or so to get oil flowing good at start. Saves engine life getting the oil in position. Headers leaking where they attach to the head will give the same noise. It doesn't need to be persistant. Temp changes can very when the leak is. My old 71 camaro with super comp headers would always loosen up then tick tick tick. Then same old wrench I'd have in the car ready for the game would shut it up. Then all I'd listen to is the .513 lift with 306 duration cam rocking hehehe. Talk about a low vacume. Oh yah try tinkering with seeing if any header bolts have gone loose. Many white gaskets need to be soaked in water before exhaust manifolds are bolted down. It makes them expand so it's a super fine fit when bolted down. If not eh. Torquing the engine around doesn't help keep the headers sealed tight either but....impossible to stop in almost 40 years of driving. Anyway, don't forget exhaust leaks at the header can sound exactly like a lifter going wrong. So besides what's already been mentioned that's about all I can add. Good luck with it.

Lifter. Since it was more pronounced on the passenger side it is probably going to be on cylinder #4. This cylinder has the most lifter issues due to the oil system routing and the fact that is generally receives less oil than the rest of the cylinders valve train wise. That lifter sounds like it has completely failed, lifters that are not pumped up thoroughly or have become dirty do not sound quite that pronounced. Its not a bad fix, just takes time, common sense and a couple of special tools.

Change the oil and see what happens. Put in something better than Mobil 0W40. It is common that a lifter may get stuck at times and does not mean it will not return to proper operation by itself.

These lifters have only one inlet, meaning oil doesn't pass through them. Because of that once a lifter becomes clogged/ obsructed its damn near impossible for it to return to normal from just changing the oil or flushing the system. You might get lucky by changing the oil and solving the problem.. If that does work IMMEDIATELY go buy a Lottery ticket. FYI- The noise coming from a stuck lifter has nothing to do with it's orientation within it's bore or if it is rotating or not.. The noise comes from the hydraulic piston not "pumping up" creating valve lash which leads to the noise..

Remember you can check the bolts attaching the headers at home and save a lot of costs. I haven't met too many people that know leaking headers will make the same sound as a lifter. Very quick fix and might need the bolt backed out and cleaned since firing exhaust near it can powder it like lube. Hopefully you didn't get a super cold batch of water that cracked some a header or head. I'll stay away from that sort of talking.

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First of all, the lifter still breaths and fresh oil is both moving in and out as the engine runs. Secondly, the noise could be from any of a dozen things, including electrical arc, pulley, cracked plug, low oil pressure, temporary blockage, exhaust leak, injector, etc, so trying to scare this guy into thinking he needs a new lifter, whether it turns out that way or not, is neither a smart nor professional diagnosis based on a low quality sound file.

If the lifter becomes clogged/ obstructed oil cannot move into or out of it due to the obstruction and the fact that the oil does not pass through the lifter. When these lifters become clogged they simply stop functioning amd once the obstruction occurs its a bit late. Ever tried to free up a completely clogged drain with drain-o before?? It works well on partially clogged drains, but not those that are completely obstructed.. Same goes here, especially when the oil feed orifice in the lifter is less than 1mm in diameter. Based on that sound file and the fact that I have heard no less than a dozen of these same sounds in the past two months (that were bad lifters) I am confident the noise is a lifter. I'd not make such a statement without great confidence because of people just like you. (Of course you'd love it if I were incorrect-) Have you ever held an M96 lifter in your hands???

Thanks guys for the info... I am relieved that this does not sound catastrophic. A few questions: Should I not start the car if, in fact, it is a lifter issue? ie: Will I cause more damage to the engine if I start the car? Does a lifter fix require the engine to be removed? There is a possibility of an issue with the exhaust as my driveway is very steep and prior to the noise, one of the exhaust tips dragged the ground as I was backing out. It happes occasionally though I try to be very careful and back out at an angle to avoid it. What would I expect to pay if this is an issue with the lifters?

If the lifter it is only partially operating the valve causing a loss of performance. It's OK to run the engine. I do believe the engine does need to be removed to get to the lifters. If you ever do an oil change make sure after starting the engine that you don't rev or high idle the engine for at least 3 minutes giving the car enough time to spred the oil to all the parts. All the air has to be displaced by the oil so 3 minutes is a good number. Call for an estimate from the shops you are debating to get the car looked at for repair. Good luck not scraping the exhaust leaving the driveway. Kind of torques the exhaust a bit and the brain a lot more having to hear it scrape. I hope it hasn't cracked your headers after seeing one mans post about prices he can't believe for just one sides muffler. Best of cruising to you.

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So, you are claiming that in the past 2 months you have confirmed more than 12 996 engines that had clogged lifters? What were they clogged with? I find that extremely unlikely. Are you develpoing a valvetrain replacement product and looking to scare people into buying it like your scare tactics with the Imaginary Mechanical Syndrome (IMS) non issue? Unless there is a mechanical breakage or blockage resulting in seizure, very few stuck lifters will not work themselves free. I assume that you realize there would be performance issues if a lifter was indeed collapsed? Do you even know what 70+ psi of oil will do to most obstructions?

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Start the car. If you are running with Mobil 0W40, change it to something else. Even a collapsed lifter would cause no damage to the engine. Drive it and observe the noise at various engine speeds and engine temperatures. It very well could have been a onetime issue. If the lifter is not working, you will also have roughness at idle and other engine speeds. Is the noise more prominent at the tailpipe? Oil pressure at idle, both cold and warm?

There is no reason for myself and 1999porsche911 to further engage in pissing contests. He doesn't care for me and I don't care for him so we should agree to disagree and both stop directing attacks toward each other. A collapsed lifter usually won't hurt performance notably at the seat of the pants. On the dyno they generally only hurt torque figures. Horsepower is generally not affected as much since the loss of valve lift isn't as notable at high RPM. Generally when lifters fail the driver has become accustomed to the performance of the vehicle over time and will not notice a slight degradation due to a one or a few failed lifters. I have seen an engine with as many as 22 failed lifters still run fine, but it did have a choppy idle. The owner could not tell his idle was choppy until I fired up another 996 next to his that was running correctly. The biggest complaint that we see with clients that have failed lifters is poor fuel economy due to a loss of chamber filling on the cylinders that have the failed/ clogged lifters. It usually takes several bad lifters to create a loss of fuel economy or a loss of power. A number of the cars we see with failed lifters/ clogged lifters never make a sound as pronounced as the one in the sound file that was posted and a few have came from dealers where they were diagnosed with zero problems. Yes, I have two cars at my facility right now for bad lifters, finished another the week before Christmas and did 3 jobs in November. The lifters in these engines do not see 70 PSI of oil pressure. The operating pressure of the oil system further up stream may be as high as 70 PSI but no where near that at the lifter valley, especially after the valley and it's passages have become partially obstructed themselves over time. When a lifter becomes obstructed the oil pressure feeding it isn't high enough to dislodge obstructions. Its all imaginary though.. even that sound bite. Damn I have a great imagination! The only damage that can be done from running the engine for extended amounts of time with a bad lifter is a slight mushrooming of the valve tip due to the valve lash thats present with the lifter thats not totally "pumped up". This takes thousands of miles and generally isn't a common occurrence.

What are the obstructions that you are referring to with clogged lifters?(old oil, particles in the oil?)Thanks Jake.

The lifters are at the furthest extremity of the oil system.. Because of this most of the contaminants in the oil (not filtered) end up finding their way to the lifters. Because the lifters only have one orifice to allow oil into them they become small "filters" that collect lots of debris. I am away from the shop through 4 January, but when I return I'll post pics of lifters I have dissected that were no longer functional. I have pictures of dozens of bad ones, not just one or two. Very seldom does a lifter fail due to anything more than being obstructed. Extended oil drain intervals that are a major contributor to this issue. It has become so common that I am shooting a DIY DVD on the topic with the step by step instructions for lifter removal and replacement in March. This can be done at home for advanced enthusiasts that have a tool box and some patience. Most shops have never ventured this deep into the M96 engine, they are certainly capable but most are just intimidated by the engine enough to not want to do the work. If they goof up it can cost them a new engine for your car. The DVD will build confidence for everyone because the work is simple.

Thnaks again for the info. When I get back to California I'm going to check the car for exhaust leaks, have the oil changed (any brand and weight suggestions?) and take a short drive to see if the problem persists. Any common places to check specifically for exhaust leaks? Should I be able to feel the leak with my hand or should I just go in and snug up all of the bolts? Thanks!

Did you ever answer the question of oil type and weight?

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+1 Also, how long has the current oil been in there?

LVDELL, I had the oil changed just after I bought the car in August (about 3000 miles ago). I took it to an indy shop that works primarily on P-cars to have the fluids changed and the car inspected. I did not ask or request a specific type or weight. I know it was synthetic and I'm pretty sure mobil 1. When I get back to LA I'm getting the oil changed because it's time and because of this recent development. Do you have any suggestions as to weight, etc...?

Jake, are there any oil additives or detergents that can be added to the oil a few hundred miles before a scheduled oil change, to maybe get some cleansing agents into the engine to keep the krud out and the various little orifices inside everything clean? I know some folks (Macster?) talk about a Techron dose before an oil change. Any recommendations?

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Personally I would put in the factory fill.....Mobil1 0W-40. Without getting into an oil debate here, some prefer to run 15W-50....even some dealers. If that is what is in your car it could very well be the problem. Without sounding like a *****, I would suggest you start paying a little more attention to your car. Know what type and weight of fluids are being used in your car is a good first start. Just telling a shop "change the oil" without knowing what they put in is just asking for troubles. If you can, find out what you indy put in during the last oil change. It should have been on the invoice? If you are feeling DIY, then oil is one of the EASIEST things you can do on your car. We'd be glad to help if you need some steps to get it done. Happy Motoring!

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Good luck with that ^ part!

Who knows Tim, maybe some have changed their ways I have, others should follow........

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SOME could have changed.... but you need ALL to change to be 100% successful! As a "stat guy," you should know this!

intofx like another pointed out it might not happen again. I suggest when starting up an engine that you let it warm up a little especially with the high performance engines. My bike doesn't go into gear till after 130F. It takes longer for a 911 to reach there but eh. You want oil on lifters, crank and rod bearings to prevent future problems. You originally mention a drive around the block. If not running up the engine so that it is nicely lubed any dry areas can become prone to sticking and or frying some oil on that surface when it gets onto the heated up surface. When that happens the area is more prone to be sticky thus clicking and even more prone to not get oil flow. Anyway back to your trip around the block. Plenty of people have had what others would call very raical rides around the block. After high rpms older engines might get clicking valves after it. If you don't drive the car much try taking it for longer drives. If it is a lifter possibly longer rides would free it up and clean some contamination off the metal surfaces. I can tell you reving an engine right after start is the worst thing to do. Some guys think its cool because race cars can be seen doing it but believe me most race engines get complete tear downs and bearings replaced. Porsche garages are always happy to supply the rebuild service. Good luck getting up to speed on what the cars are up to. Plenty of very knoledeable persons on cars got there during running engines into the ground before rebulding. Not the way to get there in your case

Thanks guys. While it may seem like I'm a novice when it comes to hi performance cars, I'm actually not. I have had more than a few sports cars each with their own quirks. Forums like this are important to me as I like to get educated as to specific issues to avoid and expect as I hate being jerked around when it seems like they have me by the short and curlys... Certainly opinions are to be expected but I understand how to read between the lines. I appreciate the info and as many others have read so many posts regarding failed IMS berrings that I just don't want to have to replace an engine because I missed the symptoms and decided to crank the car just to see if I could hear the source of the noise... Thanks Again!

**UPDATE** I got back to town, cranked the car and the noise was gone. Drove the car a few miles and everything seems fine. I will report back if there are any developments. Certainly, it's time for the oil to be changed but beyond that, it seems like it was a false alarm... Thanks again for the info. Matt

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Glad it wasn't a problem. Hope you didn't lose any sleep after listening to some of the doomsayers on this thread.

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That's starting the new year out right! Change the oil and filter and stay on top of it. Letting the oil change interval stretch out is like playing Russian Roulette with a one shot derringer: You're gonna lose and way sooner than you think. Sincerely, Macster.

On the off chance that Jake has email notifications turned on... would like to see those lifters photos posted that were mentioned earlier. Thx

Ya photos rock!!