Jet Engine noise on cold start up. . . .WTF???
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It's not the turbo. Your turbo is only spinning when there's a load, and you've got your foot deep into it.
What you are hearing is you Secondary Air Injection Pump. May be on it's way out, but you can hear it normally (although it's not that loud). It's an emissions only system, so it does not effect performance. It only runs when the engine is cold to flow additional air into your exhaust to more quickly heat up the cats.
So if it is going you'll get a CEL, and hear a heart stopping beep accompanied by "EMISSIONS WORKSHOP!" on your dash display, but it aint no thing but a chicken wing, so don't worry. It only an annoyance and can be delt with once you get sick of the light.
What you are hearing is you Secondary Air Injection Pump. May be on it's way out, but you can hear it normally (although it's not that loud). It's an emissions only system, so it does not effect performance. It only runs when the engine is cold to flow additional air into your exhaust to more quickly heat up the cats.
So if it is going you'll get a CEL, and hear a heart stopping beep accompanied by "EMISSIONS WORKSHOP!" on your dash display, but it aint no thing but a chicken wing, so don't worry. It only an annoyance and can be delt with once you get sick of the light.
Another Jason from Philadelphia, weird. Anyway, yeah I have an '02 1.8t and during the first 30 seconds or so of a cold start, at least every morning, there's like a propeller sound on top of the usual engine's low hum. I think it goes away sooner if I drive immediately. The sound persists and increases in sync with the RPM and engine sound as I drive until it suddenly goes away and I'm left with the usual wonderful sounding purr and whistle of my little turbine engine. I don't know if it's always done this, as I've only owned the car for a month and my dad owned it before me.
Mine sounds like a vacuum. Sequence of events under my hood on cold start:
* cranking
* starts, if it's below 30 degrees I get a ratcheting sound for 1 - 1.5 seconds (that the dealer can't reproduce, doesn't sound like valves, sounds like a chain dragging over something). Engine generally loud
* engine slows to more normal speed after a little bit.
* vacuum-sounding noise on top of engine noise, RPM lowers slightly
* vacuum-sounding noise stops, idle smooth and engine VERY quiet.
1.8t, now 33k+ mi. Been this way since day one.
* cranking
* starts, if it's below 30 degrees I get a ratcheting sound for 1 - 1.5 seconds (that the dealer can't reproduce, doesn't sound like valves, sounds like a chain dragging over something). Engine generally loud
* engine slows to more normal speed after a little bit.
* vacuum-sounding noise on top of engine noise, RPM lowers slightly
* vacuum-sounding noise stops, idle smooth and engine VERY quiet.
1.8t, now 33k+ mi. Been this way since day one.
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2,091 Posts
It could also be a bad accessory belt roller/tensioner bearing.
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20 Posts
If the pressure hose or intake hose from/to the SAI pump breaks, then you will hear the SAI pump. Check hoses first.
Wow you guys are very helpful. I will check all hoses and start with a timing belt. I've had the car for a year, put about 25000 miles on it and only noticed the noise in the last month or so.
Also the emissions light has been on for about 6 months. . . .had it inspected, fixed, and cleared and it came right back on the next day.
Anyway again thanks!
Also the emissions light has been on for about 6 months. . . .had it inspected, fixed, and cleared and it came right back on the next day.
Anyway again thanks!
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445 Posts
I have the same noise untill it warms up, I just did the Timing and all belts...So I would think it could be the Acc tensioner, it would seem that this is a source of the problem from what I have read here and over at AW..
Plus you have a 2000 with an updated TB tensioner most likely, an that acc tensioner is famous for these noises from what I have heard, no pun intended
TJ
Plus you have a 2000 with an updated TB tensioner most likely, an that acc tensioner is famous for these noises from what I have heard, no pun intended
TJ
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134 Posts
Jason,
I have the same car, had the same problem last year. It was the secondary air injection pump. Have it checked and if it is, call VW of America & complain. Tell them you want this documented as a pattern failure part. They agreed to pay half of the total repair bill.
Vince
PS-Also have the dealer check out your combi valve--it 's failure often causes the pump failure.
I have the same car, had the same problem last year. It was the secondary air injection pump. Have it checked and if it is, call VW of America & complain. Tell them you want this documented as a pattern failure part. They agreed to pay half of the total repair bill.
Vince
PS-Also have the dealer check out your combi valve--it 's failure often causes the pump failure.
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