E46 330Ci + New Rear Tyres: Unstable

E46 330Ci + New Rear Tyres: Unstable

Author
Discussion

helix402

7,885 posts

183 months

Thursday 25th May 2017
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A well set up E46 on decent matching tyres shouldn't tramline, regardless of tyre size. (Unless you put silly 19s on or some other oddness).

c3m

Original Poster:

278 posts

152 months

Thursday 25th May 2017
quotequote all
Can someone recommend a good quality set of tyres that are in production today that are known to be compatible with the car and not result in the car trying to kill me on a motorway?

To note, I remember when my 330Ci used to tramline a bit depending on the surface or when switching lanes. This is nothing compared to this, when I showed the effect to a passenger, they were literally scared we would crash.

HugoFastmann

279 posts

119 months

Thursday 25th May 2017
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I run Dunlop Sport Maxx RT's (now replaced by the RT II) which have been absolutely brilliant.

Zod

35,295 posts

259 months

Thursday 25th May 2017
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There is definitely something wrong. I had one in Germany at the turn of the century and it only felt less stable once it went over 140mph.

helix402

7,885 posts

183 months

Thursday 25th May 2017
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Conti Sport Contact 5 or Goodyear Eagle F1.

Mr Tidy

22,476 posts

128 months

Saturday 27th May 2017
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I've had 2 E46 Compacts (one on Continentals, the other on Pirellis), and never had a problem with tramlining so it does seem as though you have a problem OP.

But my 1 Series on Pirelli run-flats tramlined more as the tyres wore (always on the outer edges of the fronts) and any slight drop in pressure made it worse.

Since then I have had 2 Z4 Coupes on Bridgestone RFTs and both tend to tramline, although the first got much better when I had the front control arm bushes replaced!

I know this may sound a bit F1, but could one (or more) tyres have a flat-spot from your incident? Many years ago I bought a set of AMG wheels for a C-Class that had come off a written-off car, and one was so out of balance I needed a new rear wheel bearing within about 4,000 miles of fitting them!

It might be worth getting your wheels balanced before you get into major expense.

Hoe you get it sorted anyway. thumbup

4rephill

5,041 posts

179 months

Saturday 27th May 2017
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My monies on the PS2/PS4 mismatch being the issue.

Despite the tyres being from the same manufacturer, if the tyre construction, rubber compound and tread patterns are different, then it's little different to running different brand tyres front to rear.

Talk of suspension problems makes little sense to Me.

If there was an issue with the suspension, it wouldn't suddenly appear with new tyre fitted, it would already be present.

Hopefully the OP will come back to this thread with a conclusion as to what happened

(Unlike most threads of this type where you never hear what the outcome was!)




Spuffington

1,207 posts

169 months

Wednesday 31st May 2017
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4rephill said:
My monies on the PS2/PS4 mismatch being the issue.

Despite the tyres being from the same manufacturer, if the tyre construction, rubber compound and tread patterns are different, then it's little different to running different brand tyres front to rear.

Talk of suspension problems makes little sense to Me.

If there was an issue with the suspension, it wouldn't suddenly appear with new tyre fitted, it would already be present.

Hopefully the OP will come back to this thread with a conclusion as to what happened

(Unlike most threads of this type where you never hear what the outcome was!)



+1

optimate

109 posts

85 months

Thursday 1st June 2017
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i doubt very much its the tires un less there Chinese if driving there on cheap tires barley on legal limet
with shagged rear dampers with no oil abnd a busted coil spring in em and they handed better than your describing

have a look at the coils they often break right at the bottom and you have a job seeing it

iv seen mot testers miss a busted spring

Spuffington

1,207 posts

169 months

Thursday 1st June 2017
quotequote all
I don't get this and why people don't believe it can't be tyres. As one of the above posters put it - if it's happened immediately after replacing the tyres, it's the tyres. If it were anything else, it would've presented itself previously. It's a simple scientific experiment - you have a control sample - the vehicle which was fine before. The only change is tyres. It's not difficult.

Also amazes me how on forums people ask questions and then those with knowledge and experience of running these vehicles get shot down by those making hypotheses. It's one of the reasons I suggested at the outset - don't just take it from me, read the reams of threads from the early noughties of E46 owners complaining of wayward handling when changing tyres. It's a well known issue with this chassis.

I'm completely open to the fact that suspension alignment comes into it, as does cracked springs etc. But when OP was so clear about the tyres and the fact that different models of even the same premium brand can alter handling characteristics, it can be nothing else, IMO.

BTW - it's not just this chassis but many others which are susceptible to tyre models and matching. But the E46 M Sport chassis famous for it.

Rant over.

aka_kerrly

12,419 posts

211 months

Thursday 1st June 2017
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Spuffington said:
as does cracked springs etc. .
It is not too far beyond the realms of possibility that the OP does have a cracked/snapped spring that could have been disturbed when the car was jacked up to have it's tyres changed. However you'd certainly hope that a tyre fitter might notice something like that!

optimate

109 posts

85 months

Thursday 1st June 2017
quotequote all
on the e46 they often break right at the bottom and unless you know the e46 well its piss easy to totally miss a busted spring you need to know where to look

c3m

Original Poster:

278 posts

152 months

Thursday 1st June 2017
quotequote all
To provide an update, I've been travelling over the past few week so haven't had a chance to deal with the issue, so tomorrow I'll be taking the car to a nearby BMW specialist for them to take a quick look and let me know if everything is okay with the rear suspension.

c3m

Original Poster:

278 posts

152 months

Saturday 17th June 2017
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Got the RTABs replaced, issue still present. Things actually got worse: my DSC + handbrake lights are now permanently on (amber), so will need to go into a garage to get it sorted out (happened today). I reckon it's very likely to be related to the rear end swaying after the tyre change.

About a 1.5yrs ago, one of the front callipers was intermittently seizing and failed an MOT (so replaced both at the front). I'm wondering whether one of the back ones isn't also seizing and causing the rear end to weave.

Kawasicki

13,096 posts

236 months

Saturday 17th June 2017
quotequote all
what you are describing sounds a lot like a lack of linear range understeer...

you have possibly fitted tyres with significantly less cornering stiffness to the rear axle, compared to the front. Full tread depth at the rear compared to low tread depth at the front can have a significant effect on steering stability (reduced linear range understeer)

I would need to drive the car to be sure, so here is my guess.....as a result of your change the car now lacks straight line stability, and is not as damped in yaw as it should be, it will also turn into corners (in normal popping to the shops driving) with a much bigger delay, and then overshoot your intended line, the torque on the steering wheel will also be lighter about the straight ahead, further reducing straight ahead stability

To improve the stability try additional toe-in at the rear, and a little more rear tyre pressure...or fit the same tyres on the front axle.




Edited by Kawasicki on Saturday 17th June 18:15

rob_1990

25 posts

108 months

Friday 7th July 2017
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I had this very problem on my 330. Turned out one of the rear shocks was knackered. Swapped both in under an hour for about £100.

Worth a look at.

keekodog

36 posts

171 months

Friday 7th July 2017
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Wonder if the OP got this sorted?

SebringMan

1,773 posts

187 months

Friday 7th July 2017
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Indeedy.

It does seem like the tyres but then jacking the car up high does unsettle things, especially depending on where they jacked it up etc.

You have to love internet diagnosis. I know the PS4s on mine are spot on.

c3m

Original Poster:

278 posts

152 months

Wednesday 12th July 2017
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I still haven't sorted out the issue. I've been on a long holiday and don't want to deal with the issue any more. I might just drive it like that for a while until I replace the car with something newer.

SebringMan

1,773 posts

187 months

Wednesday 12th July 2017
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It was probably almost worth hanging onto the wheels! I'm still wondering rear subframe bushes.

But I have one question and it will sound silly. Are the tyres fitted in the correct orientation? I.e The outside of the tyre is facing outside.

Where in the country are you exactly?

Edited by SebringMan on Thursday 13th July 07:52