Oil in throttle body (was: Loud buzzing from intake manifold)

[julian24110]

Leon 2.0Tdi 140

Got loud buzzing coming from intake manifold. This starts as soon as you turn on ignition, continues while engine is running and carries on for 10-15 seconds after engine switched off. The noise is coming from the assembly below the inlet manifold (where the big black tube connects to the bottom) and is possibly coming from a small cylindrical shape sticking out of the right hand side of the main assembly. Noise sounds like a motor screaming, if I touch the inlet assembly I can feel it vibrating with same frequency as the noise.

Any ideas?

 

[julian24110]

OK so I've been out in the dark, noise is coming from throttle body. Teeth are broken on the cam that turns the flap so the motor is just spinning or grinding against broken teeth.

The bit that surprised me is that the inside of the throttle body and the pipes leading up to it are dripping with engine oil. When I prised off the metal cover that contains the motor and electronics, this whole thing was full of engine oil. I am assuming this is not normal. What would cause this? Overfilling?

Odd thing is car was working fine, just making awful noise. What would be the effect of putting it back together but leaving the motor disconnected?

 

[Brazzer71]

Hi Julian, i've had exactly the same symptoms and found exactly the same thing. i've been running with the throttle body / intake flap disconnected for 6 months now with no problems, apart from the orange MIL on the dash board.

If you leave it plugged in eventually it will short out blowing a fuse which also runs one of the cooling fans.

Let us know if you get it replaced, i've priced it at TPS at around £280 i think.

 

[Brazzer71]

Meant to say my plan is to fit a catch can in the rocker cover breather, to reduce the amount of oil getting into the intake, before i replace the intake flap.

 

[Viking]

Murrays Direct for the inlet manifold motor assembly. Less than £200 genuine VAG part. Bit of a bitch to fit mind.

Edit: They're selling on Ebay as well. Link.

Latest revision part number is 038128063M, earlier versions had a G or an L suffix instead of the M. Don't buy old stock!

 

[Brazzer71]

thanks viking

 

[James_R]

@Viking

thought you'd fallen off the face of the earth pal?

 

[julian24110]

Got new unit from Murrays direct. Delivered in under 24hrs for £199. Now fitted to car so all should be well? I can now hear the new unit making a high frequency whine when ignition is turned on and for 10-15 seconds after engine is turned off. just before it stops I can hear the flap moving (opening?). Admittedly I have to have the bonnect open to hear it but I do not remember this before. Anyone know if this is normal with the updated (M) unit?

My current theory is that something is causing the motor to be trying to turn all the time, hence the whining and this is what caused the teeth on the old unit to wear / break (broken teeth were where the motor toothed wheel sat against the flap drive cam when in the open position). If this is right I do not want the new unit to go the same way.

 

[Viking]

Yep, the motor in the unit doesn't just open and close. It half closes when EGR function is enabled to cause enough vacuum for the system to work properly, and it closes fully when you switch off the engine (to stall it). So the noise you hear is the motor in the unit adopting the correct position for the state the ECU tells it to.

So the motor is always moving as it's told to, rather than sitting static waiting for the engine shut down signal.

@Viking

thought you'd fallen off the face of the earth pal?

Yep, been having some time away due to many people thinking they're all it. Just a passing visit to promote Murrays as they were so good to me when I needed this part a while ago.

 

[julian24110]

Thanks Viking. So noise is normal? never heard it before but wasn't listening! Afraid I am paranoid now as had to have new Turbo less than a month ago so worried engine is starting a self destruct phase!