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Discussion Starter #1
Hi,

Does anyone else get a strange sort of vibration sound from their exhaust at about 3-4500rpm?:confused:

I have a 2.0l Manual 156 (1999) tspark,

Mine does for some reason not always but usually when under a bit more load.
A mate said it would be due to a very restrictive exhaust (which is great news if he is right, exhaust = cheap, engine = not cheap)

I don't think it is pinging or anything dam hope not,
is pinging (ie early detontation) the same sort of sound in a Tspark?????



Anyway the car is dealer bought so it is still under warranty so I want to either have the problem understood atleast and hopefully sorted soon as poss.



Oh yeah and what Temp do you guys usually run at?

Mine runs at about 80c for a while then moves to 90, this is the middle of the temp range which the manual says is fine but all my other cars (no alfas) ran much below midway.

FYI this is in the middle of the aussie summer so a bit hot would be expected but yeah just a concerned newbie who wants his problems paid for by the dealer is possible.


Anyway thanks in advance for your help.

Hope you all had a good new years!
 

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Could possibly be a hole in the muffler or somwhere in the exhaust?
If its under warranty they should have it checked and fixed with no dramas for you.
 

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Mine gives a lovely metallic rasp at around 3-3500 revs if it's any help.

Temp usually runs 80-85'c or 90 in traffic.
 
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Don't think you can get pinking (pinging?) in the newer cars as they have a knock sensor which is used to reduce this AFAIK. Anyone expand on this?
 

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I get a similar noise, almost a metalic buzzing sound, at around 2500-3500 revs especially under load. As far as I know it's not a problem, just assumed it was some slight vibration somewhere
 

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Sounds like a sympathetic resonance and nothing to worry about.

BTW, if your other cars ran cooler than your Alfa it's probably because their thermostats were knackered. Yours sounds like it is ok.
 

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yep, thermostat sounds fine. I just replaced mine and it runs under 90 (needle just cuts into the number 9 on the dial) while moving and goes up to around 95-100 when stationery until the fans cut in and bring it back down.
 

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Discussion Starter #9
Well that all sounds reassuring,
metalic buzzing sound/metallic rasp is a good description of it so I guess all is well.
Thanks for your help,

Good see this is an active forum too,

Cheers,
VH
 

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Skippy156 said:
Good see this is an active forum too,

Cheers,
VH
Skippy welcome to AO, as you say an active forum full of helpful people who love a laugh. My top site by far! :)
 

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Yeah I have it on my 2.0 156 also. It might be worth checking underneath the car and look above the exhaust and make sure the heat shield is nice and secure mine was flapping down and vibrating of the exhaust.
 

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I have the same noise from my car at the same rev range but only once the car has warmed up and been driven for a while.
I have spent ages looking through all of the exhaust sections for the cause and have finally found out that the noise is actually the engine pinking. I'm going to fit a new knock sensor next weekend to see if this sorts the problem... i hope it does because otherwise it could be an expensive fix.

Temp gauge sounds absolutely fine.

J
 
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Pinking is more of tinkling noise that a vibration.

I get some vibration from the exhaust in the same rev range.
 

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Check the cheap options first but on our 147 it turned out the catalytic converter matrix was loose and breaking apart. Eventually MCSF light kept coming on and cat. showed up on diagnosis.
 

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I've had both cats off and looked inside. Both are solid and matrix is not broken up. The noice from mine is like a metalic tinkling (can be very loud at times). My ECSF light is on but I'm sure this is due to the fuel mixure running rich as the ecu is compensating for the pinking.
 

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Another thing to check is that the balance belt is on... a certain garage has been known not to replace it after a cambelt change. (As I have found... and if one place does it, then maybe others do!)

I spent a long time looking for the source of a metallic resonance at 1800 and 3600rpm and after two yeasr traced it to this issue.

Chris
 

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i had the noise you are desribing.......it was a bracket that holds the front of the exhaust system onto the engine block. the bracket was cracked, and the 2 parts rattling together.
 

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