[harsh_ride]

This morning when I fired up my 968, I noticed a soft click followed immediately by a softer click (Click/click), once every few revolutions or so (it's a steady rhythm). It's most noticeable at idle, but as I ran her gently up to around 3,000 rpm or so, it was still there.



Somewhat paranoid, I shut her down, buttoned her up, and took the motorcycle to work instead.



Any ideas what it might be? I'll setup a video camera with an ellipsoidal mic tomorrow to capture it, if it'll help.

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[Greimann]

Has it been a few days since you drove it last? It is most likely a lifter that has bled down. Drive it till it warms and if the tick goes away, no problem.

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[harsh_ride]

[quote name='Greimann' date='May 25 2005, 04:39 PM']Has it been a few days since you drove it last? It is most likely a lifter that has bled down. Drive it till it warms and if the tick  goes away, no problem.

[right][post="5068"]<{POST_SNAPBACK}>[/post][/right][/quote]



Nope, it had only been about 14 hours since she was last out and about, and I had no radio in her the last trip (I'd taken the faceplate off at Ralph's and couldn't be bothered to unlock/reattach/etc for the .75 mile trip home). No clicking last night, just this morning.



Just got reshoed (literally; my Eccos arrived in the mail from Nordstrom's), so it's not a priority -- I've been looking for any excuse to walk the 3 miles each way to Century City for work...



What happens when a "lifter . . . has bled down"?

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[Greimann]

[quote name='harsh_ride' date='May 25 2005, 10:04 PM']What happens when a "lifter . . . has bled down"?

[right][post="5084"]<{POST_SNAPBACK}>[/post][/right][/quote]

A hydraulic lifter contains a small volume of oil that pumps up the internal parts of the lifter so it runs tight against the cam lobe and valve stem. They are also called self adjusting lifters, as opposed to the mechanical kind that would require shims or a screw adjustment to set the lash so the valvetrain runs quiet.



A lifter will sometimes bleed off this volume of oil after the car has sat for some period, and at start up, will have more clearance than usual. The lifter will tick until it has had time to pump back up again. On the 968 this may take a minute or two of driving.

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[rl968]

This is very interesting. My car does this as well. If it sits a week and then I start it, I hear the clicking sound, sounds more distinct in colder weather. After a few minutes it goes away and won't do it again unless the car sits again. I'm assuming there is nothing wrong here, but you have to wonder why they are designed like this. Would different oil matter (I use 15w-50) or is it just the way the car is?



My 86 911 has mechanical valves that are supposed to be adjusted every 15k miles or so, it has never made this noise, but I imagine this is what it will sound like when it needs a valve adjustment.

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[Martijn]

I also have a funny sound which at first did sound like a lifter stopped functioning. (didn't go away after a coulpe of minutes) Several specialist listned to the clicking sound and they all thought I should replace the lifters.

All the lifters are replaced by a trustworthy specialist and still the sound is there. After some new checks the sounds seem to come from the injectors giving a resonance through the fcam and fuelrail cover....... Injectors still work fine but are noisy. (I will not replace them for now they are hell expensive <img src="/forum/images/smilies/968/sad.gif" class="smilie" alt="" />)





Just wanted to share this info.

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[rl968]

You might have a cracked pick-up tube, in which case you should stop driving the car immediately. Ultimately, this is what was wrong with my car and it's not a cheap fix as you have to remove the oil pan. I have a thread on this that includes a short video of the noise. At first it was a faint sound, but grew louder over time as the pick-up tube cracked more. Basically, not enough oil is getting to the top of the engine, so the lifters make noise. The tube is made of thin metal so not surprised they crack, particularly if they are under heavy vibration.

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[Cloud9...68]

A lifter is basically a solid metal cylinder, and it's very unlikely for one to fail, and you're right, they're insanely expensive. I would check for other things, but like rl968 says, getting to the oil pick-up tube requires pulling the pan, for which you have to dismantle half the car <img src="/forum/images/smilies/968/ohmy.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/mad.gif" class="smilie" alt="" /> rl968 - were you getting low oil pressure readings when you had your cracked oil pick-up tube?

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[rl968]

No, there was no change in oil pressure from the pick-up tube, making it harder to diagnose.

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[Cloud9...68]

Yeah, that does make it a painful task. I'm going to install a Lindsey Racing 3-piece cross-brace when I put my car back together, to allow me to get to my pan in the future without doing 85 hours of labor, and requiring an alignment.

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[rl968]

I've heard that Lindsey racing cross-member isn't that strong compared to the one-piece stock. If you track the car, you might want to think twice.

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[Cloud9...68]

Really? All they do is cut an existing cross-member in two places, weld in a pair of flanges, and bolt in back together. I don't see why this wouldn't be just as strong as a one-piece unit. It sure would be awesome to be able to get the the pan by just removing a handful of bolts, so opposed to taking everything off the car but the carpet and paint

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[gcb729]

I like 15W50 oil, I'm in AZ even cool morning weather is warm. I wouls try some 0W40 or 5W50 and see if this helps your situation. The lighter cold weight oil will get up and moving much more quickly. Porsche has certified the 0W and 5W weight (European Formula)oils for our vehicles.

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[flash]

i have often thought about the 3 piece unit - the problem i have is torsional flex - i am concerned that the 3 pieces might not stay put relative to each other - perhaps i could install pins or something to prevent that - not sure yet - will decide when i have to pull the motor

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