Monaro 'graunch' and 'Low Traction', you know the one

Monaro 'graunch' and 'Low Traction', you know the one

Author
Discussion

SturdyHSV

Original Poster:

10,097 posts

167 months

Thursday 19th June 2014
quotequote all
Just thought I'd post up an interesting little bit of info I observed the other day that I forgot to post up.

I've not really had any of the old noise since changing to a truetrac, so I assumed it was the old stock diff being a bit weird.

This illusion was shattered ( perhaps a bit melodramatic hehe ) the other day when the following happened:

I was parked, stationary, in neutral, with the handbrake on, and attached to my battery was an old 540i I was attempting to jump start for a friend. I was holding the car at about 2,000 rpm, and when he tried to crank the BMW, naturally it pulled my voltage down a little nearer 12v, but, it triggered the Low Traction warning, and most strangely, it made the nasty graunching noise!

The first time it was just a brief graunch like it is when you pull away sometimes, I lifted off and it stopped immediately in reaction to the noise. I realised what it was when I saw the dash icon flashing, so wasn't too concerned as I was in neutral and not going anywhere.

It happened a second time, and I stayed at 2k rpm as before. This time it lasted for a good second or two and I was able to pay a bit more attention to where it was coming from, and to be honest it felt more like it was under my feet as opposed to behind me (confused face).

Either way, I presume it was perhaps some quirk to do with TCS / ABS or some oddity being triggered by a mixture of odd inputs from various sensors.

I just thought I'd share it as it was certainly the sound I used to get with the old diff when pulling away sometimes (accompanied by the 'Low Traction' message) but I was completely stationary, in neutral, handbrake on, so nothing was actually moving. As such, I wonder if it's in fact some sort of TCS / ABS bug?

j666eds

642 posts

149 months

Thursday 19th June 2014
quotequote all
SturdyHSV said:
Just thought I'd post up an interesting little bit of info I observed the other day that I forgot to post up.

I've not really had any of the old noise since changing to a truetrac, so I assumed it was the old stock diff being a bit weird.

This illusion was shattered ( perhaps a bit melodramatic hehe ) the other day when the following happened:

I was parked, stationary, in neutral, with the handbrake on, and attached to my battery was an old 540i I was attempting to jump start for a friend. I was holding the car at about 2,000 rpm, and when he tried to crank the BMW, naturally it pulled my voltage down a little nearer 12v, but, it triggered the Low Traction warning, and most strangely, it made the nasty graunching noise!

The first time it was just a brief graunch like it is when you pull away sometimes, I lifted off and it stopped immediately in reaction to the noise. I realised what it was when I saw the dash icon flashing, so wasn't too concerned as I was in neutral and not going anywhere.

It happened a second time, and I stayed at 2k rpm as before. This time it lasted for a good second or two and I was able to pay a bit more attention to where it was coming from, and to be honest it felt more like it was under my feet as opposed to behind me (confused face).

Either way, I presume it was perhaps some quirk to do with TCS / ABS or some oddity being triggered by a mixture of odd inputs from various sensors.

I just thought I'd share it as it was certainly the sound I used to get with the old diff when pulling away sometimes (accompanied by the 'Low Traction' message) but I was completely stationary, in neutral, handbrake on, so nothing was actually moving. As such, I wonder if it's in fact some sort of TCS / ABS bug?
I have noticed the 'ro does all sorts of weird and wonderful things when it gets a lower than normal voltage. I usually get the low traction message/noise when i pull away with not enough rev's and almost stalling the engine.

MyM8V8

9,457 posts

195 months

Thursday 19th June 2014
quotequote all
SturdyHSV said:
Just thought I'd post up an interesting little bit of info I observed the other day that I forgot to post up.

I've not really had any of the old noise since changing to a truetrac, so I assumed it was the old stock diff being a bit weird.

This illusion was shattered ( perhaps a bit melodramatic hehe ) the other day when the following happened:

I was parked, stationary, in neutral, with the handbrake on, and attached to my battery was an old 540i I was attempting to jump start for a friend. I was holding the car at about 2,000 rpm, and when he tried to crank the BMW, naturally it pulled my voltage down a little nearer 12v, but, it triggered the Low Traction warning, and most strangely, it made the nasty graunching noise!

The first time it was just a brief graunch like it is when you pull away sometimes, I lifted off and it stopped immediately in reaction to the noise. I realised what it was when I saw the dash icon flashing, so wasn't too concerned as I was in neutral and not going anywhere.

It happened a second time, and I stayed at 2k rpm as before. This time it lasted for a good second or two and I was able to pay a bit more attention to where it was coming from, and to be honest it felt more like it was under my feet as opposed to behind me (confused face).

Either way, I presume it was perhaps some quirk to do with TCS / ABS or some oddity being triggered by a mixture of odd inputs from various sensors.

I just thought I'd share it as it was certainly the sound I used to get with the old diff when pulling away sometimes (accompanied by the 'Low Traction' message) but I was completely stationary, in neutral, handbrake on, so nothing was actually moving. As such, I wonder if it's in fact some sort of TCS / ABS bug?
Did you apply the E40 PCM patch yet?

SturdyHSV

Original Poster:

10,097 posts

167 months

Friday 20th June 2014
quotequote all
MyM8V8 said:
Did you apply the E40 PCM patch yet?
Yep, it's all fully patched up. Is there a simple option that disables the TCS straight away? I tried setting the TCS disable RPM really high (i.e. if it falls below this level disable it) and the TCS enable even higher, but it's still on by default when I start the car...

It's annoying pressing the button every single time hehe


granjuiceymoose

309 posts

160 months

Tuesday 17th November 2015
quotequote all
I'm glad you posted a link to this as I've had that noise/feeling a couple of times but couldn't begin to think what I'd call it in order to search the forum. I take it it's just another quirk of these cars as I was fearing the clutch was on its way out, only the infrequency of it occurring stopped me changing the clutch.

BlueDevil

414 posts

204 months

Tuesday 17th November 2015
quotequote all
MyM8V8 said:
Did you apply the E40 PCM patch yet?
Just out of interest what's the E40 patch?

SturdyHSV

Original Poster:

10,097 posts

167 months

Tuesday 17th November 2015
quotequote all
BlueDevil said:
Just out of interest what's the E40 patch?
It's an OS patch in EFI live to maintain certain functionality when going MAFless thumbup

L2VXR

975 posts

213 months

Wednesday 18th November 2015
quotequote all
with you noticing this noise when you rev the engine and putting load on the alternator could it be the clutch pulley on the alternator as I have a similar noise on my grand cherokee. you can actually see the belt lagging over the pulley when you let off the revs as though it's struggling to spin the pulley and you get a strange whooshing grinding noise.

Major Monaro

276 posts

129 months

Wednesday 18th November 2015
quotequote all
I also get this sometimes, I'm surprised no one has an answer or solution yet. Lol

Edited by Major Monaro on Wednesday 18th November 22:14

V8TFT

335 posts

183 months

Wednesday 18th November 2015
quotequote all
SturdyHSV said:
Yep, it's all fully patched up. Is there a simple option that disables the TCS straight away? I tried setting the TCS disable RPM really high (i.e. if it falls below this level disable it) and the TCS enable even higher, but it's still on by default when I start the car...

It's annoying pressing the button every single time hehe
This small wiring harness will disable the TCS everytime you start the car. The TCS switch still works so you can turn it back on if you want.
http://www.speedinc.com/shop-by-vehicle/2004-2006-...

SturdyHSV

Original Poster:

10,097 posts

167 months

Thursday 19th November 2015
quotequote all
V8TFT said:
SturdyHSV said:
Yep, it's all fully patched up. Is there a simple option that disables the TCS straight away? I tried setting the TCS disable RPM really high (i.e. if it falls below this level disable it) and the TCS enable even higher, but it's still on by default when I start the car...

It's annoying pressing the button every single time hehe
This small wiring harness will disable the TCS everytime you start the car. The TCS switch still works so you can turn it back on if you want.
http://www.speedinc.com/shop-by-vehicle/2004-2006-...
Hmm, it is annoying, but it's not quite $57 + shipping + duty + running a fused 12v line annoying hehe

Interesting to know that it's do-able though thumbup

bigwheel

1,618 posts

214 months

Thursday 19th November 2015
quotequote all
SturdyHSV said:
Hmm, it is annoying, but it's not quite $57 + shipping + duty + running a fused 12v line annoying hehe

Interesting to know that it's do-able though thumbup
I don't think it would need a live feed. It appears to be a cable to plug in between the TCS switch and the wiring loom multi-connector.
Your right about the $price. FFS! All it effectively does is change the polarity configuration with-in the TCS switch.

V8TFT

335 posts

183 months

Thursday 19th November 2015
quotequote all
You just plug in the loom and connect it to a switched feed. You can also unplug it and go back to the original setup if you want. There is a mini circuit card within the loom that simulates turning the switch off, so the switch still works like normal.

I found a way on the net to modify the wiring and add a relay that should work. It wasn't reversible and not proven, so I opted on buying the loom instead.


Yanayaya

912 posts

184 months

Thursday 19th November 2015
quotequote all
SturdyHSV said:
It's an OS patch in EFI live to maintain certain functionality when going MAFless thumbup
I want this.

bobfredstinker

783 posts

150 months

Friday 20th November 2015
quotequote all
I get this fairly regularly too. Normally happens when pulling away as you say, accompanied by the 'low traction' message. I've found that when it happens a few times in succession it is cured by turning off the traction control. I have also found it happens very occasionally when braking to a stop, and it can by physically felt through the brake pedal. Could be similar to what you were saying in your first message.

Much like everyone else, I'm unsure as to the causes. It does seem, though, like it might be some kind of gremlin in the TCS (otherwise why would turning it off make a difference?), but I can't really imagine why it would do it when not in gear and stationary!

Anyone with a non-original TCS getting it?

SturdyHSV

Original Poster:

10,097 posts

167 months

Friday 20th November 2015
quotequote all
bobfredstinker said:
I get this fairly regularly too. Normally happens when pulling away as you say, accompanied by the 'low traction' message. I've found that when it happens a few times in succession it is cured by turning off the traction control. I have also found it happens very occasionally when braking to a stop, and it can by physically felt through the brake pedal. Could be similar to what you were saying in your first message.

Much like everyone else, I'm unsure as to the causes. It does seem, though, like it might be some kind of gremlin in the TCS (otherwise why would turning it off make a difference?), but I can't really imagine why it would do it when not in gear and stationary!

Anyone with a non-original TCS getting it?
This is the kind of response I was hoping for, I'm inclined to agree that it felt like something ABS / TCS related, although the TCS just cuts the power in my (limited) experience with it on, it doesn't apply any sort of brake activity as far as I'm aware?

bobfredstinker

783 posts

150 months

Saturday 21st November 2015
quotequote all
SturdyHSV said:
bobfredstinker said:
I get this fairly regularly too. Normally happens when pulling away as you say, accompanied by the 'low traction' message. I've found that when it happens a few times in succession it is cured by turning off the traction control. I have also found it happens very occasionally when braking to a stop, and it can by physically felt through the brake pedal. Could be similar to what you were saying in your first message.

Much like everyone else, I'm unsure as to the causes. It does seem, though, like it might be some kind of gremlin in the TCS (otherwise why would turning it off make a difference?), but I can't really imagine why it would do it when not in gear and stationary!

Anyone with a non-original TCS getting it?
This is the kind of response I was hoping for, I'm inclined to agree that it felt like something ABS / TCS related, although the TCS just cuts the power in my (limited) experience with it on, it doesn't apply any sort of brake activity as far as I'm aware?
I am not the most technically minded of people on this forum, but by my understanding all it does is cut the throttle a little (or a lot), in quite a blunt instrument kind of way - nothing like the kind of advanced systems you'll get in the likes of McLarens and Ferraris which actually put a bit more science into it.

I have no idea why I have felt it through the brake pedal too, or even what is actually physically happening when it does that noise. Clearly it's somewhere in the drivetrain, and most people suggest it's the diff, but that wouldn't help in explaining why it happened in neutral as the diff would not be moving.

I'm fairly stumped by it to be honest.

Mnchsv

58 posts

101 months

Saturday 21st November 2015
quotequote all
If you voltage drops below 12v your abs / traction control won't like it

bigwheel

1,618 posts

214 months

Saturday 21st November 2015
quotequote all
Might the graunch noise be the ABS motor cycling?

bobfredstinker

783 posts

150 months

Sunday 22nd November 2015
quotequote all
bigwheel said:
Might the graunch noise be the ABS motor cycling?
That wouldn't explain the link to the Traction Control or why it happens when pulling away.