Immediate idle speed kick down on cold start

[texadelphia]

My 08 Avant, 2.0T has recently started kicking down the idle to around 800 rpm almost immediately on cold starts. I've had the car about a month and until recently it would idle around 1200 rpm for about 60-90 seconds before it would kick down to normal idle. The only factor that may have changed is that it's gotten much colder here at night but I would think that would cause it to idle higher, longer...not the opposite. Is this a sign of anything I can be concerned about? Other than that it seems to be running normal.

The only known issue I have is that the vacuum pump nipple that goes to the brake booster line is rattling on cold start. If I open the hood I can see the hose rattling in the housing. I also had a random misfire code pop up last week but hasn't come back since.

[MacFady]

If I remember correctly this is completely normal, my B6 did the same thing consistently for my whole ownership once the outside temperature falls below a certain point. Won't notice your SAI pump turn on at start-up either when it's ~ 0C and below. That being said, if you drive the car, park it, and start it later you may notice it start as it does in warmer temps depending on how cold the car has become in the interim.

Again, if I remember right, not getting into specifics but the higher RPM initially is more for emissions reasons and heating the CAT up as quickly as possible. These processes lose their efficiency once it gets below a certain temperature so the SAI pump does not run at start-up and the initial idle becomes low to prevent engine wear.

[DownhillA4]

This is normal operations during the colder months / climate areas. Nothing to be alarmed about.

[Theiceman]

B7 does not have an SAI pump.
Operation is normal
you can replace the oring in the nipple that vibrates, if you do a search you will find the p/n and dimensions. people have fixed it gooping jb weld on it . it does work like a treat but is a bit unorthodox

[oVeRdOsE]

I have a 08 2.0t, and iirc , mine does hold the idle high in winter. right now is around -3°C in the morning.

I believe my neighbors would like having the same ''issue'' as your. 1200 rpm with an exhaust is loud in the morning.

[MacFady]

B7 does not have an SAI pump.

I don't have one so I wasn't sure, nice to know.

[texadelphia]

Thanks guys. Glad to know it's normal operation aside from overdose's experience.

I have seen that JB weld fix but mine is also leaking oil from the housing so I'm planning on just replacing it. Just dragging my feet as it looks like it's a pain to work on the back of the engine. I'm probably putting it in the shop for control arm bushings soon so I may just have them take care of the vacuum pump while they're at it.

[oVeRdOsE]

Thanks guys. Glad to know it's normal operation aside from overdose's experience.

I have seen that JB weld fix but mine is also leaking oil from the housing so I'm planning on just replacing it. Just dragging my feet as it looks like it's a pain to work on the back of the engine. I'm probably putting it in the shop for control arm bushings soon so I may just have them take care of the vacuum pump while they're at it.

ill try to notice it tonight. It might do the same as your, but I did not noticed any difference winter/summer. Im owning it since 3.5 years.
summer here can go 30°C, and winter -25°C

[lumberwood]

With a mirror, and a Micro-ratchet (like Eastwood offers), the vacuum pump is a cinch to do. I'd save the $$ in labour and do it yourself, as the part will also be cheaper if you source it from ECS, FCPEuro, etc...
Thanks guys. Glad to know it's normal operation aside from overdose's experience.

I have seen that JB weld fix but mine is also leaking oil from the housing so I'm planning on just replacing it. Just dragging my feet as it looks like it's a pain to work on the back of the engine. I'm probably putting it in the shop for control arm bushings soon so I may just have them take care of the vacuum pump while they're at it.

- Corey

[texadelphia]

With a mirror, and a Micro-ratchet (like Eastwood offers), the vacuum pump is a cinch to do. I'd save the $$ in labour and do it yourself, as the part will also be cheaper if you source it from ECS, FCPEuro, etc...

- Corey

OK, I'm convinced. I actually bought a mirror, a magnet, and a mini-ratchet a couple weeks ago just in case I got up the gumption to do it and I think your post just gave me the nudge I needed.

[lumberwood]

OK, I'm convinced. I actually bought a mirror, a magnet, and a mini-ratchet a couple weeks ago just in case I got up the gumption to do it and I think your post just gave me the nudge I needed.Excellent.
Take your time with the three mounting bolts (do not drop them), set the new pump head to mate w the cam face (match it to the old one), and give it a wiggle on the way in to seat the o-ring (I put a dab of spit on it to lubricate instead of oil).
The vacuum line just pulls off, once the clamp is removed (cut it off, carefully) so give it a firm but slow tug to get it off.
You'll need a new clamp for the vacuum line, a small hose clamp from the hardware store will do nicely. Have that on hand before you start.

**Hot Tip: With the pump removed, you can clearly see the cam follower where it rests against the cam lobe. Have a good look w your mirror to make sure it's flush on the lobe, and the pump hasn't punched its way through the follower. (if this is the case, that's the next job you'll need to do but finish up the pump job first)

You got this!


- Corey

[texadelphia]

Excellent.
Take your time with the three mounting bolts (do not drop them), set the new pump head to mate w the cam face (match it to the old one), and give it a wiggle on the way in to seat the o-ring (I put a dab of spit on it to lubricate instead of oil).
The vacuum line just pulls off, once the clamp is removed (cut it off, carefully) so give it a firm but slow tug to get it off.
You'll need a new clamp for the vacuum line, a small hose clamp from the hardware store will do nicely. Have that on hand before you start.

**Hot Tip: With the pump removed, you can clearly see the cam follower where it rests against the cam lobe. Have a good look w your mirror to make sure it's flush on the lobe, and the pump hasn't punched its way through the follower. (if this is the case, that's the next job you'll need to do but finish up the pump job first)

You got this!


- Corey

Yeah, the lack of access back there and fear of dropping a bolt in my black gravel and pine needle driveway was the biggest reason I've been avoiding it. Here's hoping my butter fingers don't get the best of me.

That's good to know about the cam lobe access. The follower was replaced when I bought the car so I'm not concerned about it but I am kind of curious what the shape of the lobe looks like. The last time it was in the shop they told me that the rail pressure was below spec slightly so I'm wondering if the lobe is worn. Although it's an '08 so I think it should have the 2 piece camshaft with the hardened lobe. I guess we'll find out.

[Theiceman]

yeah that easy beer money saved doing the pump . Be careful with that black plastic vacuum line , pry it off, don't start pulling or it might snap $$ ( you can pry it out of the firewall too... )

the trickiest bolt is the one at the bottom with the ground on it . take your time ( throw a tarp under the car in case the bolt drops. Also when putting it back make sure the ground bracket is oriented correctly and sits flat, or you might strip out that bolt hole. id get back there and take a pic with your phone before you start ...
after you are done drink the couple of cases of beer with the money you saved.
you can save even more if you rebuild your pump with the orings from ebay for this for about 30 bucks.

[texadelphia]

yeah that easy beer money saved doing the pump . Be careful with that black plastic vacuum line , pry it off, don't start pulling or it might snap $$ ( you can pry it out of the firewall too... )

the trickiest bolt is the one at the bottom with the ground on it . take your time ( throw a tarp under the car in case the bolt drops. Also when putting it back make sure the ground bracket is oriented correctly and sits flat, or you might strip out that bolt hole. id get back there and take a pic with your phone before you start ...
after you are done drink the couple of cases of beer with the money you saved.
you can save even more if you rebuild your pump with the orings from ebay for this for about 30 bucks.Thanks for the tips. I've read some mixed things about the rebuild kit, like it will eventually start leaking again and only buys some time.

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[Theiceman]

Thanks for the tips. I've read some mixed things about the rebuild kit, like it will eventually start leaking again and only buys some time.

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well have not done it myself as I am even too cheap to spend the 30 . I think quite a few have been successful with the ebay kit however.

[texadelphia]

Just a follow-up. Ambient temperature was up to 43F this morning and 60 second 1200rpm idle returned. Past couple mornings with immediate kickdown have been down around 35F.

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[texadelphia]

Anyone see anything unnecessary or flawed in this guy's approach? I don't have any triple square bits so I'm wondering if I can get away without removing that bracket.

https://youtu.be/m0aveJi8EEI

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