Noise expers! Startup noise, any clues?

Hi, I have a rarely occurring startup noise, sounds like (yikes!) metal on metal just at the very initial milliseconds I crank the engine. It has only happened when cold starting and only a few times in the past 3+ months. I took it to the dealer and their mechanics tried to replicate it. Wouldn't you expect that they'd never hear it??? That always happens, right? Well, the very first time they started up the car, they heard it. ;-) But, they were so startled (I don't think they believed me when I described the problem) that they didn't get a chance to listen to where it was coming from. They've had the car a week and it hasn't happend since. I tried to get a sound clip but all I've been getting is the nice sound of my car starting up and no bad noise. The mechanics are guessing that there is a chip somewhere in the starter that, if lined up right, will cause the noise. They are saying that it's so rare that I shouldn't worry. I'm worried. Any clues? What's a ballpark cost for a starter replacement? My warrenty is gone and I'm already in the hole $600 for a cracked coolant bottle this trip to the repair shop... ;-( Thanks for any info.

The only thing I can think of is your hydraulic valve lifters knocking until oil pressure is built-up. That is perfectly normal for any car. My GT3 does it too. If the noise does not go away after a few seconds, then you need to be concerned.

Hi Viken, First of, as a sometimes passive reader, thanks for the wealth of info you (and others like you!) provide. I can't say enough of how much it is appreciated. Next the noise, yes, it stops almost the instant you hear it. Seconds would not describe how long it lasts, more like tenths of a second. It sounds like it is coming from the engine compartment on the driver's side but that may be just because I'm sitting in the driver's seat at the time. It *almost* sounds like the cranking noise you'd hear if your battery was dead but I've got a full 12 volts there. I guess my life was just becoming too worry free. Wow, I'm impressed that my meager C4Cab can do anything like a GT3... Too bad it's not a performance thing. ;-)

Is the sound "raspy" for a brief moment and then goes away? Mine did that if it had sat for a while. I was told it was lifters. I was also told to use the 0 w40 oil to help get oil "up" quickly to make the symptom go away. It did not go away.....I tried 15 w 50 and I have not heard it since I changed my oil. Made my life easier too, as now all my vehicles use the same oil.

If you don't drive the car for an extended period of time, you sometimes get the lifter noise for a few seconds/minutes, which goes away once the oil has had a chance to circulate. My last Carrera was a weekend car, and sometimes I didn't drive it for a few weeks, and it would make the lifter noise when first started, but it would go away shortly thereafter.

You're welcome, Joe. Get back to worry free. You've got no problems regarding this noise.

I have what I call a "screetch" sound at startup when the car is cold and the air is damp. It occurs rarely. But it must be dmp and cold. It lasts barely a second. probably a fraction of a second. It does sound like metal on metal I guess. Like you, I have not been able to get a sound clip as it never shows up when I am set to record it But.... I am fairly certain, in my case it's the starter motor pulley. I have found that if I dip my finger in oil and then apply it extremely lightly to the pully, I can go weeks without ever hearing the sound again. The dealer said they will replace the pully at next service. Hope this helps.

The what?

Foot removed from mouth..... Ahem.... read alternator not Starter motor.

Grtetch, I wouldn't describe the sound as "raspy". To me, raspy doesn't have a metallic "squink" (if I can borrow a Seindfeld-ism) Scouser, I think you hit it with the "screetch" sound. Hmmm, alternator motor pully. I think I'll have my mechanic check that. Can you let me know how much it costs to get that one repaired? Thanks!

Beware! I had an intermittant noisey starter that began within the warranty period, but of course the Dealer could never replicate. 10,000 miles out of warranty and the noise occurred more and more and of course the dealer finally heard it...yep, replace the starter. But that requires, I was told, a complete dropping of the engine on my '99 C2 Cab, so 5 grand later I've got a new starter that I frankly believe should have been covered under warranty. By the way, I had them replace the clutch and plate and CV boots while in there but that brought the total to 9 grand. Not pleasant to say the least. The caveat is to ruthlessly make the dealer document any problems or concerns during warranty. Because this dealer failed to make note of my complaints starting at 36,000 miles, they would not help on honoring this repair under warranty. Good luck. George B.

It is very common for the belt pulley and tensioner bearings to go on these 996's. Just had my '01 serviced (one bearing reayplaced) and the noise is gone. They sell the bearings with pulleys for about $25 each of $75/set on ebay.

I have the screech too. Just like Scouser, it needs to be colder than usual and damp. I always thought that the sound was related to the mufflers somehow, but maybe not. Either way, it only lasts for literally the first burst of throttle as I'm starting it up, then it's immediately gone. Hasn't ever really bothered me so I haven't looked into what it might be...

Sounds like a new starter motor is needed. Has that screeching start upon startup and got progressively worse to point replaced uner warranty at that time. It started up fine but the noise was killing me. After was done all is well. Regards. Mike

I have the same loud metallic noise occasionally at start up. I took it in and they could not find anything wrong. Mine mostly occurs when the engine is warm. It sounds like someone tapping the engine once with a hammer. It�s still under warranty and I only have 3500 miles on it so unless it gets worse I will ignore it.

sorry for bringing up an old thread but my car seems to only have this metalic sound (when hot) as soon as the starter releases and the motor fires. (a couple of milliseconds). i was hoping that people that have had this problem will chime in. thanks

I have the same problem as well. On startups where the engine has sat for more than 12 hours, immediately after the starter fires the engine makes this same rattle. Took it to the dealer; they stated the oil dripped off the lifters and it was "normal". It stops immediately after the engine starts to idle after the initial revs.

I had the exact same noise. It was a screech. a metallic, annoying, i hope nobody notices me, loud screech. Diagnosis: you need a new starter motor. Just to inform you, mine did not depend on long term parking, or hot or cold weather. It did it say...one time every 10-15 startups. (About 1-2 days worth for me). Then more often, and more often... yada yada yada... EVERY DAMN TIME I STARTED THE CAR!!! I would actually wait for people around me to be out of sight before i turned the engine over because it was, well... embarassing as hell!!! I had mine changed for the uh-hum reasonable price of $457.00 (price/labor). It took my guy about 4-6 hours. No engine removal needed, but he showed me where the part is and to be quite honest, it looks as if it would be easier to do the job with engine removal. Anyways, now I can hear only the beautiful startup purr than only a p-car can make. No more screeching noise. Good luck Peter

thanks guys. i can confirm the following. - the car has stood for about 4 hours and i went to start it. no noise... cranked it about 5 times in succession and i can hear the noise comming back. - i dont think it is lifter noise and it is not a belt "shriek" sure it is starter related.... oh..it does it all the time when hot.

$5K to change a starter in this car!? That's Ferrari-esque! That alone convinces me tol get a zero deductable full coverage extended warranty for this car before the factory runs out...

I assume you have ruled out the LIC plate banging sometimes at startup?

On 3 occasions, I noticed a light puff of white smoke in my exhaust for a few moments after starting the car. On all three occassions, the car had been sitting idle for a week or more. On another occassion, I shut the car down while it was still hot from a session on the track. I NEVER did this to my car before (I always took a cool-down lap before killing the engine) but a unique set of circumstances caused me to do it this time. After the engine ran for a few minutes, all signs of the smoke disappeared. So my questions are simple. 1) Is it normal to see white smoke in the exhaust in these circumstances? 2) What exactly is causing the smoke? 3) Is it possible to damage the engnie by shutting in down while it's still hot from a track session? If so, why?

Thats completely ridiculous. You dont need to drop the motor to do starter. It is a bit of a chore to get to but its almost just as bad with the engine in. I wouldn't go back to that shop again.

On Mercedes engines a metallic rattle at start up is from the cam chain tensioner slightly collapsing. The chain briefly rattles until oil pressure builds and tightens the tensioner. Sometimes if the engine stops with a valve lifter part way up a cam lobe, it will put tension on the chain and will tend to collapse the chain tensioner more. I think my turbo sometimes does the same thing. I don't think it's a problem.

I get a knock or two when starting the engine when its warm. I assume that the knock sensor is not online yet (no sense messing with the cam timing when starting the engine is a priority) and there's some detonation. It stops in less than a second.