BMW DSC Help!

weekaizer

Ive just bought some new alloys for my 320d e90 (Standard m sport suspension)
New tyres are 265/30/r19 rears and 245/35/R19 fronts...
The car had previoulsy had 18" alloys on with 255/35/18 amd 225/40/18.
Having drove the car on them this evening, i noticed the traction control light is flickering on every time i try and floor it or take a corner quicly and its cutting power to the car substantially... if i turn the DSC off it resolves the problem.
Does anyone have any similar experiences of this and if so how can it be solved?..
Ive already checked all the tyre pressures, 38 rear and 35 fronts...

Northern Monkey

What sort of tyres are on the new rims? 38 seems slightly high for the rears as well.

challengemaster

Are the tyres cheap chinese ****e?

If yes, there's your problem

YbFocus

When I got my e60 it had generic tyres on it and the reaction light would flicker in 4th!

My sportmaxx's hardly allow you spin in second when I want to

I'd say it's the tyres, if anything a larger rim would cause more inertia and a wheel that's harder turn!

weekaizer

The fronts are uniroyals and the rears are maxtrack...( i couldnt afford the massive rears in a good brand...)
The rears are very wide at 265/30 and i like the tyres firm so 38 what i thought i would try first.. i can reduce the tyre pressures but dont i dont think that will solve the issue as the problem was there even when the wheels were bolted straight on by the garage...
I stopped to check the pressures, one of the rears was 32 and the other 38..:eek:
I have also reset the tyre pressure sensors twice.

YbFocus

If your resetting the pressures you have a puncture, 38 is to high and you'd be losing grip in fairness, no forgiveness in the tyre if you will.

challengemaster

Maxtrek tyres are ****e to start.

Coupled with overinflated and I'm not surprised DSC is kicking in.

Get new quality rear tyres.

jhegarty

Is there ice on the road ?

That would send the dsc off on one.

weekaizer

No, i meant I reset the pressure sensor once after the wheels were initially fitted and the second time was after i readjusted the tyre pressures myself at the next garage on way home...
No ice on the roads at all...
Maxtrack i accept are poor tyres but i had sunny tyres on my e46 320d before with no such problems, only time the DSC would come on would be at very high speed.
Its coming on now even at low speeds when turning corners...
I understand what ye are saying, i will see in the morning when its dry if the problem is any better.

Satanta

Your tyres are sh1te man. I haven't seen a good review for the maxtrek.

weekaizer

What tyre pressures would people recommend for these tyres....?
According to the plate inside the door of the car it says the recommended tyres are 255/30R19 for rear and 225/35R19 for fronts...
Perhaps the wheels could be too wide for the car and it is upsetting the wheel sensors?...

challengemaster

No. The problem is the rear tyres are too shít, and can't keep traction.

You need to replace them with decent tyres.

Gumbo

Either way if reduced the tyre pressure on the rear to 34 and the fronts to 32. Or check the metal panel on the drivers door. 19" was an option on the E90 so recommended pressure is listed.

Paddy@CIRL

265/30 is fine on the rear of an E90, the problem is with the tyres themselves. I usually run 32psi in the front and 36psi in the rear on 19s and never had a problem. I'm running 255/30 on the rear of mine in a Hankook Ventus Evo and I would struggle to break traction in second.

Change your tyres before you end up backwards in a hedge.

bazz26

Running ****e plastic tyres like Sunny/Maxtrek on a rwd car is really asking for trouble.

OP not specifically singling you out here but in general it amazes me the amount of people who can buy nice shiny new alloy wheels and then put the cheapest crap tyres on them.

challengemaster

bazz26 wrote: »

Running ****e plastic tyres like Sunny/Maxtrek on a rwd car is really asking for trouble.

OP not specifically singling you out here but in general it amazes me the amount of people who can buy nice shiny new alloy wheels and then put the cheapest crap tyres on them.

Saw nankangs on the rear of an Audi r8 in Mayo about 2 months ago

Literally facepalmed

aristotle25

bazz26 wrote: »

Running ****e plastic tyres like Sunny/Maxtrek on a rwd car is really asking for trouble.

OP not specifically singling you out here but in general it amazes me the amount of people who can buy nice shiny new alloy wheels and then put the cheapest crap tyres on them.

Its not just people. A main BMW dealer sold a BMW 530d to my brother with sunnys on it. Scary thing is most people would not be aware that those tyres are just dangerous on most cars, never mind a 230bhp rear-wheel drive.

unkel

weekaizer wrote: »

i couldnt afford the massive rears in a good brand...

Then buy part worn tyres in a good brand! They will cost less than the cheapest new Chinese tyre.

TheBazman

When you put on new tyres you will always have reduced grip for a few hundred kms. I put new bridgestones on rear of my e60 last week and the dsc was lighting up like a christmas tree when you accelerated. All fine after a day or two with a bit of driving.

bazz26

aristotle25 wrote: »

Its not just people. A main BMW dealer sold a BMW 530d to my brother with sunnys on it. Scary thing is most people would not be aware that those tyres are just dangerous on most cars, never mind a 230bhp rear-wheel drive.

I never let the dealer replace tyres on a car I am buying off them. I prefer to haggle more off the price and replace them myself than leave the dealer replace them with the cheapest possible tyres they can get.

weekaizer

Just to update I changed the scrap rear tyres to uniroyal Rainsport 2 and I am still having the exact same issue. So clearly the tyres are not the problem here.

bazz26

An ABS sensor could have been damaged when the tyres were changed. The next step I would do is take it to a garage with diagnostic software and have any fault codes read.

weekaizer

bazz26 wrote: »

An ABS sensor could have been damaged when the tyres were changed. The next step I would do is take it to a garage with diagnostic software and have any fault codes read.

Already have done that bazz26,
he has had the car for past 2 weeks!
No faults recorded on computer even as he was driving other than dsc light coming on and off...

Mefistofelino

The original 18" set up had tyres that had the same rolling radius - at any given speed, front and back turned at the same RPM. With the 19" set up as described, the rear tyres now have a smaller rolling radius than the front and have to rotate more (around 2%) than the front to maintain the same speed.

The DSC is comparing the front and rear rotational speeds - rear wheels running faster than the front is taken as wheel spin. I guess the actual wheelspin (under acceleration) plus the "apparent" wheelspin (due to tyre size difference) is over the allowable limit so the DSC kicks in.

You could try playing around with tyre profiles until the circumference matches

http://www.willtheyfit.com/

jimgoose

Mefistofelino wrote: »

The original 18" set up had tyres that had the same rolling radius - at any given speed, front and back turned at the same RPM. With the 19" set up as described, the rear tyres now have a smaller rolling radius than the front and have to rotate more (around 2%) than the front to maintain the same speed.

The DSC is comparing the front and rear rotational speeds - rear wheels running faster than the front is taken as wheel spin. I guess the actual wheelspin (under acceleration) plus the "apparent" wheelspin (due to tyre size difference) is over the allowable limit so the DSC kicks in...

^^^
This. BMW DSC is not simple traction control, it monitors the four wheels, including the current steer angle.

Paddy@CIRL

Did you reset the TPMS to allow for the new rolling radius?

Mefistofelino wrote: »

The original 18" set up had tyres that had the same rolling radius - at any given speed, front and back turned at the same RPM. With the 19" set up as described, the rear tyres now have a smaller rolling radius than the front and have to rotate more (around 2%) than the front to maintain the same speed.

The DSC is comparing the front and rear rotational speeds - rear wheels running faster than the front is taken as wheel spin. I guess the actual wheelspin (under acceleration) plus the "apparent" wheelspin (due to tyre size difference) is over the allowable limit so the DSC kicks in.

You could try playing around with tyre profiles until the circumference matches

http://www.willtheyfit.com/

All the E90s and most other modern BMWs run their tyres like this. A 30 profile rear, 35 profile front is what's recommended by BMW on a 19" wheel.

weekaizer

ATM the rear tyres are 265x30 r19
The fronts are 235x35 r19

I noticed before I even bought the wheels that according to the plate inside the door the manufacturer recommends 225 35 fronts and 255 30 rears (iirc) so the profile appears to be correct if slightly wider than recommended.
I would have gone with the manufacturers set up only for I notice loads of other e90s have the slightly wider tyres fitted with no issues whatsoever, and the tyre shop say that 235 and 265 are always fitted to the 19" alloys they sell...

Paddy@CIRL

weekaizer wrote: »

ATM the rear tyres are 265x30 r19
The fronts are 235x35 r19

I noticed before I even bought the wheels that according to the plate inside the door the manufacturer recommends 225 35 fronts and 255 30 rears (iirc) so the profile appears to be correct if slightly wider than recommended.
I would have gone with the manufacturers set up only for I notice loads of other e90s have the slightly wider tyres fitted with no issues whatsoever, and the tyre shop say that 235 and 265 are always fitted to the 19" alloys they sell...

The tyre sizes are spot on, there's countless E90s the world over running these sizes without the issues you're having. In case you missed it, have you tried resetting the TPMS sensors?

Also, is the car lowered? When was the last time it was four wheel aligned?

weekaizer

Also, is the car lowered? When was the last time it was four wheel aligned?[/quote]

Never lowered, just standard m sport suspension, had 4 wheel laser alignment done few months ago.. I hav reset tpms already with no success.

Paddy@CIRL

Before I would go any further, I'd have it realigned again somewhere reputable (not saying where you got it done originally wasn't). The DSC units in the E90 are notorious for giving problems, mine was replaced before I bought the car. I don't think the symptoms match up though.

weekaizer

For anyone reading this with similar problems. Just to conclude the problem got sorted with a pair of rear abs rings which were a tenner each on eBay.
BMW in their wisdom don't sell these rings even though they are removable from car, they insist that a whole half shaft must be replaced when this issue arises! Think I was quoted over €350 for a half shaft !

Big Nasty

Sorry to resurrect this slightly old thread but can I ask what speeds this was happening at OP? Have a similar problem myself in an E39 but only at motorway speeds. Definitely not the tyres either. Ran diagnostics and no faults coming up.

weekaizer

It could have happened at any speed over 30ish mph. Over rough ground, accelerating or even coasting over bumps. Problem is that this issue doesn't show up any diagnostic faults other than the actual dsc flashing light!.

Best way to diagnose the problem is to jack the car up remove the rear wheels, use an Allan key to remove the rear speed sensor (usually around the rear of the brake caliper). Carefully pull out the sensor and use a flashlight to peer in the hole and while turning the rear wheel around have a check to see if there is any signs of excessive wear or even rust from the abs rings inside.

Also while the sensor is out you can use an air line to blow out and dirt from the hole. You never know it may be a cheap fix!

Big Nasty

With me it's only happening at speeds in excess of about 65mph on smooth ground but yeah, could well be the cause of it.

Cheers man.

weekaizer

Big Nasty wrote: »

With me it's only happening at speeds in excess of about 65mph on smooth ground but yeah, could well be the cause of it.

Cheers man.

When I first noticed the problem it was speeds in excess of 50 but then it went away for a while but when I sold the 18s and the car was sitting up a while I then fitted 19s and problem was far worse then so I guess it could be early stages of worn abs rings.. Only other possible problem would be mismatched tyres or bad 4 wheel alignment..
Good luck with the troubleshooting!

Big Nasty

weekaizer wrote: »

When I first noticed the problem it was speeds in excess of 50 but then it went away for a while but when I sold the 18s and the car was sitting up a while I then fitted 19s and problem was far worse then so I guess it could be early stages of worn abs rings.. Only other possible problem would be mismatched tyres or bad 4 wheel alignment..
Good luck with the troubleshooting!

My problem first appeared when I got part worns fitted last year. Went straight back to them and they insisted the tyres are laser tested prior to sale and it wasn't the tyres. I've been using part worns for a few years now and never had an issue with them before. They did alignment foc also when I went back to them and that made no difference. They suggested it could be the speed sensor at that point.

Diagnostics was showing no faults so the next possibility was the ABS module. Buddy is a mechanic and also breaks a few cars so he changed out the sensors and module no joy. This was all over the course of a good few months as the car does mostly urban driving and the problem only arose at speeds in excess of 65mph which is only occasional so I just switched off the DSC on long journeys and forgot about it.

Got new rubber (brand new not part worn) fitted yesterday and drove to Galway, problem still there. I'm thinking now that maybe when the part worns were fitted last year that they may have belted off the wheels or dirt got in where these ABS rings are and fooked sh1t up!