With the rattling and lack of performance it sounds like a broken waste gate
actuator (part of the turbo). It can be replaced separately from the turbo for
USD 180 plus three hours labor. They will probably try to get you to buy another
K03 turbo and at you mileage that might be a good idea as they tend to go out at
90K to 100K miles.

It could just be a bad diverter valve but the rattling is symptomatic of the
actuator being bad.

I replaced my broken waste gate actuator last May but had DIY help and access to
free used parts.

TonyJ
98.5 A4 1.8 TQM APR

michael.an.wei@gmail.com wrote:
> It is 2002 Audi A4 1.8T Quattro. Have 60,000 miles on the clock. Could
> it be the problem of timing belt?
>
> msheppy wrote:
>
>>What engine? How can anyone even begin to guess without knowing what
>>engine is in the car?
>>
>>
>>On 24 Nov 2005 11:14:31 -0800, michael.an.wei@gmail.com wrote:
>>
>>
>>>I just bought an Audi A4 2002. I is great running over 40mph on
>>>freeway. But it is kind of tickling noisy when I accelerate from idle
>>>speed. I feel the vibration and noise from padle and wheel. During the
>>>first 2-3 seconds on start, I can obviously feel the car move much
>>>slower than the normal Audi, after then, it runs good. The other thing
>>>is that when the car decelerate to about 20mph, I can feel the knocking
>>>noise. It is a kind of low pitch noise. And every morning when I cold
>>>start up the car, it has a crazy noise like diesel car. But it runs
>>>away 2 or 3 mins after.
>>>
>>>I am juust wondering what can be the problem of those symptoms. I am
>>>going to dealer (not audi dealer, the dealer I bought this car from)
>>>next Monday. I hope I can know something before I go there.
>
>

 

Tony, thanks for your reply.

It only happens when I try to start from the idle speed. After it gets
speed over 40 mph, it runs fine. I would think it is barely a turbo
problem since it happens at too slow speed for Turbo to kick in. Any
thoughts on that?

 

Tony, thanks for your reply.

It only happens when I try to start from the idle speed. After it gets
speed over 40 mph, it runs fine. I would think it is barely a turbo
problem since it happens at too slow speed for Turbo to kick in. Any
thoughts on that?

 

Tony, thanks for your reply.

It only happens when I try to start from the idle speed. After it gets
speed over 40 mph, it runs fine. I would think it is barely a turbo
problem since it happens at too slow speed for Turbo to kick in. Any
thoughts on that?

 

Tony, thanks for your reply.

It only happens when I try to start from the idle speed. After it gets
speed over 40 mph, it runs fine. I would think it is barely a turbo
problem since it happens at too slow speed for Turbo to kick in. Any
thoughts on that?

 

I can't think of another likely candidate.

Still, when the Wast gate actuator is bad the rod connecting to the wast gate
rattles easily and could make a noise just from engine vibration which is more
at lower engine speeds.

I think I remember that this is new to you so I would say that you may not be
aware of loss of turbo boost because you haven't driven it when it is correct.

When mine was bad I couldn't wait to get it fixed. Boost is addictive especially
when the ECU is chipped and boost is 16 - 18 PSI rather than the stock 7 - 11. I
have the basic 1 bar APR chip. Makes it a completely different ride.

You should consider adding a boost / vacuum gage. They are rather cheap, fun to
watch and are a great diagnostic tool.

michael.an.wei@gmail.com wrote:
> Tony, thanks for your reply.
>
> It only happens when I try to start from the idle speed. After it gets
> speed over 40 mph, it runs fine. I would think it is barely a turbo
> problem since it happens at too slow speed for Turbo to kick in. Any
> thoughts on that?
>

 

I can't think of another likely candidate.

Still, when the Wast gate actuator is bad the rod connecting to the wast gate
rattles easily and could make a noise just from engine vibration which is more
at lower engine speeds.

I think I remember that this is new to you so I would say that you may not be
aware of loss of turbo boost because you haven't driven it when it is correct.

When mine was bad I couldn't wait to get it fixed. Boost is addictive especially
when the ECU is chipped and boost is 16 - 18 PSI rather than the stock 7 - 11. I
have the basic 1 bar APR chip. Makes it a completely different ride.

You should consider adding a boost / vacuum gage. They are rather cheap, fun to
watch and are a great diagnostic tool.

michael.an.wei@gmail.com wrote:
> Tony, thanks for your reply.
>
> It only happens when I try to start from the idle speed. After it gets
> speed over 40 mph, it runs fine. I would think it is barely a turbo
> problem since it happens at too slow speed for Turbo to kick in. Any
> thoughts on that?
>

 

I can't think of another likely candidate.

Still, when the Wast gate actuator is bad the rod connecting to the wast gate
rattles easily and could make a noise just from engine vibration which is more
at lower engine speeds.

I think I remember that this is new to you so I would say that you may not be
aware of loss of turbo boost because you haven't driven it when it is correct.

When mine was bad I couldn't wait to get it fixed. Boost is addictive especially
when the ECU is chipped and boost is 16 - 18 PSI rather than the stock 7 - 11. I
have the basic 1 bar APR chip. Makes it a completely different ride.

You should consider adding a boost / vacuum gage. They are rather cheap, fun to
watch and are a great diagnostic tool.

michael.an.wei@gmail.com wrote:
> Tony, thanks for your reply.
>
> It only happens when I try to start from the idle speed. After it gets
> speed over 40 mph, it runs fine. I would think it is barely a turbo
> problem since it happens at too slow speed for Turbo to kick in. Any
> thoughts on that?
>

 

I can't think of another likely candidate.

Still, when the Wast gate actuator is bad the rod connecting to the wast gate
rattles easily and could make a noise just from engine vibration which is more
at lower engine speeds.

I think I remember that this is new to you so I would say that you may not be
aware of loss of turbo boost because you haven't driven it when it is correct.

When mine was bad I couldn't wait to get it fixed. Boost is addictive especially
when the ECU is chipped and boost is 16 - 18 PSI rather than the stock 7 - 11. I
have the basic 1 bar APR chip. Makes it a completely different ride.

You should consider adding a boost / vacuum gage. They are rather cheap, fun to
watch and are a great diagnostic tool.

michael.an.wei@gmail.com wrote:
> Tony, thanks for your reply.
>
> It only happens when I try to start from the idle speed. After it gets
> speed over 40 mph, it runs fine. I would think it is barely a turbo
> problem since it happens at too slow speed for Turbo to kick in. Any
> thoughts on that?
>