Throttle Body Noises

[RichB86]

Was poking around in engine bay this weekend and noticed the throttle body was making some weird noises, i wedged the pedal down popped off intake hose and took this video.

the clicking and wine is from the throttle body, and the butterfly is wobbling slightly with the clicking.

is it knackered? i know a few people havent been able to connect to it with vag com or vas.

[Interphase]

Strange sound, that. I wonder if one of the wheels in the geartrain that controls the valve and houses the angle sensors has slipped or lost a tooth? It's almost as if there's something interfering with one of the angle sensors and it's oscillating around what should be the correct position.

[Guest westallc]

sounds fecked buddy...sounds like above

p.s i have one for sale in the for sale section

[RichB86]

sounds fecked buddy...sounds like above

p.s i have one for sale in the for sale section

payday on fri, i maybe in contact!

[Guest westallc]

okay mate its here ready to go...

[RichB86]

If i take the black plastic side off the throttle body, will i be able to get it back on? or am i going to break something in the process as its a non serviceable unit or something silly.

[Interphase]

I know that people remove the side whilst reconditioning them, but the only one I've seen with the side off had already been opened so I don't know how cleanly they go back on. I'd probably only chance it if you're ok with replacing it should things go pearshaped

Thing is, short of removing debris and putting cleaner on the tracks, I don't know how easily you could source replacement parts if you did discover anything broken. Might be more useful if you're interested in what's going on in there rather than intending to repair it.

[gocfella]

Having just cleaned mine, I noticed that mine was doing this also. Maybe it is knackered? Could this be why the cleaning of it had a big impact on my hesitation problem but did not cure it completely? Would this fluttering plate have much effect on air flow under WOT?

[chicken_eyebrow]

gocfella is yours throwing a fault code?

I remember cleaning the throttle body on another members car (Suze) which had a 17705 error and this got rid of the error code permantently but her throttle body was still moving and making random noises afterwards, but didn't seem to affect performance or anything so as far as I know she's just kept going with it.

[gocfella]

My car had no fault codes before or after throttle body cleaning. Hopefully from what you say, the slight fluttering is not causing any problem and I will continue to try to isolate the problem elsewhere!

[chicken_eyebrow]

Yeah, you could buy a new throttle body but if it's not throwing up any fault codes and if it's not affecting the drive then it'd be cheaper just to live with it

[RichB86]

there is one for sale on here cheap if it does throw up any issues.

[gocfella]

Thing is, I don't know if it's affecting the drive! My hesitation is less noticeable after the cleaning but still there. I guess I can live with it but it's always going to annoy me until I get it sorted for good. I am going to check the DV next... These problems seem to be caused by so many different factors that it's a little disheartening for a new owner...

Yeah, you could buy a new throttle body but if it's not throwing up any fault codes and if it's not affecting the drive then it'd be cheaper just to live with it

[Guest westallc]

still got one for sale cheapest you will find and in perfect working order and will not throw any codes up:thumbup:

look in the for sale section..

going on ebay soon for a higher price so grab a bargain

[gocfella]

her throttle body was still moving and making random noises afterwards, but didn't seem to affect performance or anything so as far as I know she's just kept going with it.

@westallc - I dont think that this could be causing that much of an issue, but was just asking someone elses opinion. Thanks for letting me know you had one though. Id be rightly sickened if I bought it and it didnt improve things! Cheers lads.

[flowy]

Today I opened my bonnet, turned ignition key one click, and noticed my throttle body was making weird sounds.

Exactly the same sort of sounds as in the YouTube video in this thread.

It's sounds like someone loading up a cassette game to an old ZX81 computer, but on low volume.

I'm going to leave mine for now, because no noticeable loss in performance. I might scan, check the variables.. which from memory should be in the 2-6 range at rest, and/or default reset it later with VCDS.

Edited 26 June, 2011 by flowy

[Interphase]

Mine does this too - you especially notice it when it's doing a basic setting on ignition position 1. If you pop the side off all you'll see is a couple of big white plastic gears with conductive tracks (looks like graphite) and a circuit board with a small wire brush that contacts each track. There's absolutely nothing to them at all, which makes the replacement price even more laughable. It is possible to clean the tracks, which generate a lot of dust and crud as they wear. You can also get a lot of stuff out from around the spindle that connects to the valve.

[rk696]

Maybe you need to d a throttle body adaptation with vagcom? The ECU might think the flap isn't at full travel when it is.

[Interphase]

I've done that quite a few times, and it makes no difference - you'll hear the sound through the adaptation. It's just feels like and feedback loop because the ECU can't maintain a stable resting position, so you get it frittering above and beyond the target setting as it tries to stabilise. The geartrain and spindle inside mine were solid with no play, so I can only assume it's an error in the calculations.

[rk696]

Is there any water or corrosion in the multiplug on the tb, or the ECU? It may be a hgih resistance joint that's screwing it up.

[Interphase]

Did you know there's a notice out for FSI engines detailing exactly the same issue (angle sensor 2 implausible) that I've been having with my MK1 for years? They put that down to iffy wiring and connectors between the ECU and TB and recommend an overlay of all 6 wires, but they can't (or won't) connect that *precise* problem to older engines. I'd already arrived at that conclusion on my own, but only replaced the affected signal wire - it seems that any wire can trigger a fault, and it almost always shows up as an issue with sensor 2!

One thing I did notice is that the connectors at the ECU end become surprisingly slack over time - the difference between new and old ones is shocking. I always wondered what the lack of shock protection on the ECU mounts might do, and reckon that's probably it.

[flowy]

Did you know there's a notice out for FSI engines detailing exactly the same issue (angle sensor 2 implausible) that I've been having with my MK1 for years? They put that down to iffy wiring and connectors between the ECU and TB and recommend an overlay of all 6 wires, but they can't (or won't) connect that *precise* problem to older engines. I'd already arrived at that conclusion on my own, but only replaced the affected signal wire - it seems that any wire can trigger a fault, and it almost always shows up as an issue with sensor 2!

One thing I did notice is that the connectors at the ECU end become surprisingly slack over time - the difference between new and old ones is shocking. I always wondered what the lack of shock protection on the ECU mounts might do, and reckon that's probably it.

I'm going to file that wiring/connectors possibility to my mind, in case the issue becomes worse for me, as a possible solution to get a garage to carry out if it needs a new 'overlay'. Thank you.

There's absolutely nothing to them at all, which makes the replacement price even more laughable. It is possible to clean the tracks, which generate a lot of dust and crud as they wear. You can also get a lot of stuff out from around the spindle that connects to the valve.

Yes a new replacement looks mightly expensive after you've had a poke around inside an old one.

[flowy]

Just detailing the steps I've taken, and plan to take, in attempting to resolve this. I've changed my mind about 'leaving it be; due to it still working despite the strange noises, in case it fails. I might as well explore the more simple causes which might be a remedy, if it prevents the throttle body failing later.

1. Yesterday evening cleaned the throttle body out (in situ). Thought perhaps if it was overly dirty that it might be preventing the throttle body and butterfly establishing default position. Got access to it, but found it wasn't overly dirty. Used some carb cleaner and did clean a thin layer gunge around the butterfly. However when turning ingition on afterwards, it didn't fix the throttle body strange sound issue. I've not got my/our VCDS cable at home at the moment (share it with a friends) so haven't yet tried to reset it that way yet.

2. Afterwards I went back to the car, opened the driver's door, and it occurred to me there was a sound I was not hearing. The fuel pump priming on car door opening. Up until recently it always primed on opening the door, but I can't tell exactly when it must have stopped doing so. The interior lights came on so not a problem with door switch. The fuel pump still primes the secondary way, when key turned on notch in ignition.

So I'm wondering if the issues are linked, but I have no aptitude or knowledge whatsoever when it comes to wiring. If the fuel pump relay has failed in its main function, maybe its emitting some mutantised unprocessable half signal and in some way that is reaching the throttle body? Long shot, but I've bought a new fuel pump relay on ebay a couple of hours ago, and plan to fit it at the weekend, if it's arrived by then, in the hope it might fix that sound coming from the throttle body, as well as priming the fuel pump when driver's door opened.

[flowy]

Note: As I understand it, the fuel pump relay should signal pump to prime on driver's door open (perhaps not when there is sufficient pressure in the system from very recent use), but the secondary way for the pump to prime is via signal sent when ignition key is turned. My car is failing on the driver's door opening with no priming sound it used to make, so that's why I suspect the fuel pump relay.