help with weird startup noise
#1
help with weird startup noise
Hi folks,
I have a noise on startup that sounds like a very loud tapping noise when I start the car, but the noise is only when I'm in gear and medium on the gas. If the car is in neutral and I rev the engine, no noise. It goes away about a minute or two after the car has been running, but will come again when the car has been sitting (off) for a couple hours or so. I've heard the valve tapping theory, but that should happen all the time, not just when I'm in gear and on the gas. It could almost sound like an exhaust leak, but I'm pretty sure that's not it.
Any ideas?
Thanks,
Warren
I have a noise on startup that sounds like a very loud tapping noise when I start the car, but the noise is only when I'm in gear and medium on the gas. If the car is in neutral and I rev the engine, no noise. It goes away about a minute or two after the car has been running, but will come again when the car has been sitting (off) for a couple hours or so. I've heard the valve tapping theory, but that should happen all the time, not just when I'm in gear and on the gas. It could almost sound like an exhaust leak, but I'm pretty sure that's not it.
Any ideas?
Thanks,
Warren
#3
I am thinking something in the drivetrain needs grease..
So it only happens when the car is cold, under moderate acceleration?
What about hard acceleration?
Does it go away under coasting? (in gear, foot off accelerator, no brakes)
Do you feel any vibrations?
What is the frequency of the tapping (fast slow) and does the frequency change with speed?
If you shift while acclerating, does the noise disappear then reappear when you resume acceleration?
What about hard acceleration?
Does it go away under coasting? (in gear, foot off accelerator, no brakes)
Do you feel any vibrations?
What is the frequency of the tapping (fast slow) and does the frequency change with speed?
If you shift while acclerating, does the noise disappear then reappear when you resume acceleration?
#4
Re: I am thinking something in the drivetrain needs grease..
>So it only happens when the car is cold, under >moderate acceleration?
>What about hard acceleration?
It happens mostly when cold, and moderate to hard acceleration makes the noise. I try not to get on the gas hard when it's cold, but anything above moderate gas will make the noise. I've noticed that parking the car after it's warmed up, and driving it again 1-2 hours later will still produce the tapping noise, though not as loudly.
>Does it go away under coasting? (in gear, foot >off accelerator, no brakes)
It may be there but it's considerably quieter...it is REAL loud when I give it the gas. I experimented again today with the car in neutral and gassing it, and it was there, but a lot quieter than when the car is in gear. No vibrations.
>What is the frequency of the tapping (fast slow) >and does the frequency change with speed?
The frequency does increase as more gas is applied. As for the frequency, I'd guess it starts getting obvious when it's maybe 3-5 taps/sec but that's just a guess.
>If you shift while acclerating, does the noise >disappear then reappear when you resume >acceleration?
Yes, the noise will subside and then resume as soon as I'm on the gas. It's most obvious in 2nd, right as I come out of first.
Thanks for the help,
Warren
>What about hard acceleration?
It happens mostly when cold, and moderate to hard acceleration makes the noise. I try not to get on the gas hard when it's cold, but anything above moderate gas will make the noise. I've noticed that parking the car after it's warmed up, and driving it again 1-2 hours later will still produce the tapping noise, though not as loudly.
>Does it go away under coasting? (in gear, foot >off accelerator, no brakes)
It may be there but it's considerably quieter...it is REAL loud when I give it the gas. I experimented again today with the car in neutral and gassing it, and it was there, but a lot quieter than when the car is in gear. No vibrations.
>What is the frequency of the tapping (fast slow) >and does the frequency change with speed?
The frequency does increase as more gas is applied. As for the frequency, I'd guess it starts getting obvious when it's maybe 3-5 taps/sec but that's just a guess.
>If you shift while acclerating, does the noise >disappear then reappear when you resume >acceleration?
Yes, the noise will subside and then resume as soon as I'm on the gas. It's most obvious in 2nd, right as I come out of first.
Thanks for the help,
Warren
Thread
Thread Starter
Forum
Replies
Last Post
Eugene G.
Audi A5 / S5 / RS5 Coupe & Cabrio (B8)
4
01-05-2012 06:53 PM
aubiexx
A4 (B5 Platform) Discussion
12
10-20-2002 03:31 PM