MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: Wills1309 on November 18, 2021, 07:32:16 pm

Title: Knock sensor
Post by: Wills1309 on November 18, 2021, 07:32:16 pm

Hi, I have a 55 plate Gti, my garage says it is down on power.  So it's been in for diagnostics this week.  Fault code relates to "knock sensor" Many other ancillary components ruled out like fuel pump. A split diverter valve was found and replaced but made no difference. Garage says next step would be to access the sensor, however they say it's a days labour to get to it.  Any thoughts from anyone?

NB it's a good garage with a very good rep, Audi specialists

Title: Re: Knock sensor
Post by: LC5F on November 18, 2021, 10:15:35 pm

Pelican parts do a good guide to see what is involved:
https://www.pelicanparts.com/techarticles/Volkswagen_Golf_GTI_Mk_V/48-ENGINE-Knock_Sensors_Replacement/48-ENGINE-Knock_Sensors_Replacement.htm (https://www.pelicanparts.com/techarticles/Volkswagen_Golf_GTI_Mk_V/48-ENGINE-Knock_Sensors_Replacement/48-ENGINE-Knock_Sensors_Replacement.htm)

It appears to be intake manifold and oil cooler off - I would say an entire day doesn't sound right.
But with all those parts off its a good time to replace the thermostat & coolant sensor - that is if they are unknown condition. also intake valves could be de-carboned too.

Title: Re: Knock sensor
Post by: Wills1309 on February 12, 2022, 03:11:53 am

Thanks for reply.  Has anyone ever tried this job?  Does anyone understand how to torque the sensor bolts on instillation?  I think there is a special tool as no room for a torque wrench?  Does anyone have an opinion on how likely it is the sensor change will resolve performance issue?  Garage have quoted £700 but can't guarantee sensor change will remedy.

Title: Re: Knock sensor
Post by: LC5F on February 12, 2022, 10:11:24 am

Looks like a crows foot like below would get into the gap:
(https://www.qy1.de/img/kraehenfuss-schraubenschluessel-337520-1.jpg)

What were they including in the £700 - sounds a bit high to me, I would try a few more places.

Title: Re: Knock sensor
Post by: Wills1309 on February 12, 2022, 11:52:22 am

Ok Yep Crows foot,. But I'm still stuck on how to torque the bolts.  £700 does sound high mostly labour.  That's why I considered doing myself, well with a friend who is much more capable than me.  But looking at guide were stuck on how to torque the bolts in the confined space. 

Title: Re: Knock sensor
Post by: LC5F on February 12, 2022, 12:33:59 pm

um, the torque wrench connects to crows foot and they torque the bolt.

The distance of the crows foot will slightly change the amount of torque - but I would just drop the torque a lb or 2 & rely on thread lock.

Title: Re: Knock sensor
Post by: pudding on February 12, 2022, 12:40:31 pm

Make sure you do stick to the torque spec as it's critical with knock sensors  :happy2: