So I posted here a while ago with a question regarding my Golf and a strange whining noise it made on cold starts. I took it in to the dealer to find out what was going on (warranty) and they said it was the secondary air pump making the noise and that it was normal. I just wanted to check to see if anyone else has either 1. Had this noise and knows about it, or 2. Knows if the service people were right or just blowing me off.
Thanks so much.
The secondary air injection (SAI) system will run on cold starts to help burn uncombusted fuel until the engine is warmed up. How long does it whine, and what engine do you have? Whining can be characteristic of a failing SAI pump.
Have you checked the VW/Golf forums? I am sure if this is a common and known issue, someone would have posted there.
I’ll assume this is an electric air pump . . . not belt driven
Yes, they can be heard in the passenger compartment, with the hood closed and the windows up
Nothing to worry about
@jtsanders is correct . . . the pump will activate on cold starts
I have found electric air pumps to generally be louder than belt-driven air pumps
If there was a technical service bulletin, recall, etc. on the pump, concerning noise, the dealer would almost certainly have adhered to it and followed the applicable instructions, when you took the car in. Apparently it did not meat any criteria for replacement at that time
I do not think the dealership was just blowing you
I remember when Benz came out with a new engine, which had electric air pumps. And the previous engine had belt-driven pumps. Several of the customers needed reassurance that the whining noise was normal operation.
The electrical secondary air pump introduces air into the exhaust system to light off the catalytic converter faster. This reduces emissions.
When you start to hear a whining or something that sounds like a jet engine on a cold start, that’s an early indication that the secondary air pump is starting to fail.
This component is covered for 2 years/24,000 miles under the EPA emission control warranty.
But, if the failing secondary air pump doesn’t cause the Check Engine light to come on, the dealer isn’t required to replace it.
I hear the electric air injection pumps often on other makes, I don’t see many VWs
Eight years ago I powered an old air pump on the bench, they are loud with the inlet and outlet open, sounds like a leaf blower.
Some of the older among us may remember the belt driven air pumps back in the 70s and 80s that were prone to rattling like a can of rocks.
That usually led to removal of the pump belt and sometimes; removal of the air injection pipes which were replaced with pipe plugs.
Hi everyone. Thank you for the feedback. The engine is a 1.8L 4cyl. The noise lasts for 3-4 seconds. Now that the weather is warmer i definitely hear it a lot less though. It seems like it’s not a life or death thing for now and that if it does fail I have another year to sort it all out. Thank you all for your help!
Benz used the belt-driven air pump until the early 90s
In our fleet, we even have GM trucks from the late 90s with belt-driven pumps
They seem to sound okay, until the bearings go. Then they sound “like a can of rocks” as @ok4450 said
@“the kid”, go to a VW dealer and test drive a 2015 Golf TSI and see if it does the same thing. Do the test first thing in the morning so the car hasn’t been out for another test drive. The dealer doesn’t need to know why exactly. Tell the salesman you might buy one if you like it enough. Only a small fib. You did drive one and like it enough to buy it.