Anyone here experience noisy lifters on start-up?
06-26-2003, 04:32 AM
#11
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Not caused by friction as such. It is just the excess clearance between the back of the ...
cam lobe and the top of the follower.
Fresh oil usually stops it for a while.
Fresh oil usually stops it for a while.
06-26-2003, 04:37 AM
#12
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I see. I assume the noise is because of the time it takes the oil pump
to lift oil to the top of the engine, meaning it runs dry for a couple of seconds? I remember reading somewhere (a long time ago, so recall is hazy) that it's something to do with the way Audi design the oil transport within the engine or something. A "design feature" of sorts...
06-26-2003, 04:52 AM
#13
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More or less. It is not so much oil flow as pressure....
the hydraulic tappets have a small piston inside them that spring loaded. It is oil pressure behind that piston that keep the clearance at its correct amount. The combination of the spring and a small ball bearing relief valve should retain some pressure whilst the engine is not running. Contaminants in the oil that are too small to be filtered out can cause the ball-bearing valve to lose a perfect seal releasing the pressure and allowing a too large clearance, hence the noise.
It does not do any real harm but sounds awfull and effects cam lift and timing and as a result performance. This is partly why race engines have solid lifters using schims to adjust the clearance. The other unpleasant feature of hydralic lifters is that at high revs they can pump up too much causing the valve to be held open a few thou all the time. This is a really unwanted effect as it causes mis-firing, burnt valves and destroys CATS etc....
It does not do any real harm but sounds awfull and effects cam lift and timing and as a result performance. This is partly why race engines have solid lifters using schims to adjust the clearance. The other unpleasant feature of hydralic lifters is that at high revs they can pump up too much causing the valve to be held open a few thou all the time. This is a really unwanted effect as it causes mis-firing, burnt valves and destroys CATS etc....
06-26-2003, 05:23 AM
#14
I think this is why Audi dealers periodically put in off-the-wall viscosities like 20W50.
It may permit a quiet start-up, but who knows what it is doing after that!
When I start my car, I think of the clatter as music, testifying to the water thin-ness of the oil which is rapidly circulating through my turbo bearings. Lifters are cheaper than turbos (I think).
When I start my car, I think of the clatter as music, testifying to the water thin-ness of the oil which is rapidly circulating through my turbo bearings. Lifters are cheaper than turbos (I think).
06-26-2003, 05:43 AM
#16
AudiWorld Super User
Never heard it from my A8, but many times from my 5 cylinders
My A8 has never made the noise. My 87 5KSQ would make the noise after about 5,000 miles on the oil (Mobil 1), I would change it and it wouldn't make it after start up until I got up in the miles again.
My 91 200q (4 valve 5 cyl motor) would do it when the oil level was at the low end of the dipstick, once I had an oil cooler leak and that was the first time I heard it because the oil level was getting too low.
I would check the oil level and consider changing the oil if it has more than 5,000 miles on it.
I use Mobil 1, but I don't want to start a discussion on synthetic. Any good dino oil or synthetic will serve you well in your normally aspirated engine.
pw
My 91 200q (4 valve 5 cyl motor) would do it when the oil level was at the low end of the dipstick, once I had an oil cooler leak and that was the first time I heard it because the oil level was getting too low.
I would check the oil level and consider changing the oil if it has more than 5,000 miles on it.
I use Mobil 1, but I don't want to start a discussion on synthetic. Any good dino oil or synthetic will serve you well in your normally aspirated engine.
pw
06-26-2003, 07:45 AM
#19
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Hey MP. Mine does the same thing.. but it does it most in the AM after sititng...
overnight. It is a little worrisome and I'm mentioning it to my rep when she goes in monday.. Its been happening since I got it and I dont know why.. Anytime I hear metal on metal it concerns me tho.. I'll post back if I find anything..
06-26-2003, 07:48 AM
#20
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I would guess that it's a function of new engine and M1 0W-30
which I think is the factory fill. Unlikley to do any harm, but you should raise the question with the dealer when you have the opportunity. I think it may stop on its own once you are change the initial fill. But becasue the dealer will use dino oil (unless the policy has changed fo rthe '03) you'll want to take your own synth to them. So switching to 5W-30 may well reduce the noise as others have said and can't do any harm.