Dogmatic6 said:
If you didn't know it was flat and no warning light came on, how do you know it was flat for 3 months?
It was presumably only part deflated for much of the time
Z4 + Snow
- Thread starter frankiefish
- Start date
If you didn't know it was flat and no warning light came on, how do you know it was flat for 3 months?
It was presumably only part deflated for much of the time
cj10jeeper said:
Hi there
yeah your right, I noticed aslight change in the handling 3mths prior to the car going in for its service. BMW said it had a slow punctur and was completly flat. When I got it change obvoisly the handling was improved at high speed.
So I'm guessing the wheel was at least part deflated for those three months
Sorry didn't make myself clear but I was impressed by the runflat tire holding up.
You need to check the pressures much more often, every 2 weeks minimum. Do it for the sake of safety, ecomony and even tyre wear.
I think BMW were wrong. The warning will come on if the pressure drops by a certain amount even if it occurs over a period of time (slow puncture). My warning light came on recently for that reason, a very slow punction over a period of about 3 weeks- yes I forgot my own 2 week rule!. The tyre was fine when reinflated but lost pressure of around 4psi every 2 weeks. (28 instead of 32). When the light came on I hadn`t checked them for 3 weeks and after I raised the pressure of that tyre and reset the warning, it didn`t happen again if I checked and inflated it each week.I have since replaced it.
I think BMW were wrong. The warning will come on if the pressure drops by a certain amount even if it occurs over a period of time (slow puncture). My warning light came on recently for that reason, a very slow punction over a period of about 3 weeks- yes I forgot my own 2 week rule!. The tyre was fine when reinflated but lost pressure of around 4psi every 2 weeks. (28 instead of 32). When the light came on I hadn`t checked them for 3 weeks and after I raised the pressure of that tyre and reset the warning, it didn`t happen again if I checked and inflated it each week.I have since replaced it.
On the UK cars the system operates by a difference in rotational speed of the wheels, measured by the ABS sensor. It therefore doesn't matter if it's a slow or quick puncture as once there is any detectable difference the part deflated tyre will be rotating at a different speed to its opposite number and therfore trigger a warning.
Anyway back to snow and driving in it
I can't believe it that we've had the first snow at my home. Amazing that all the country is at a standstill in every compass point from here and we've had just frost so far. Real snow for the morning now
Anyway back to snow and driving in it
I can't believe it that we've had the first snow at my home. Amazing that all the country is at a standstill in every compass point from here and we've had just frost so far. Real snow for the morning now
cj10jeeper said:
Question on this... sort of - watching the Top Gear Polar Challenge (superb TV!), anyway, I noticed then they were deflating the tyres that the Toyota has two sets of valves on the rims... what's that all about? Is it just a fail safe or something more clever?
On the Zed front... only problems I had in the snow were getting in and out of the drive and into the office car park! Thankfully the wonderful car has a boot wide enough for a shovel.
I think my "deflate the tyres" plan may have backfired on me big-time actually 
Having re-inflated the tyres, one keeps going down - seems to be leaking between the tyre and the rim, not sure if the tyres just got dislodged on the rim a bit too much or whether I've damaged the rim whilst the tyres been deflated. The roads are so bad round here I wouldn't be surprised if I've bent the rim on a pot-hole - I do vaguely remember going over one that made me a bit worried a few days back, not sure now whether the tyres were inflated fully or not.
Oh well, will have a better look tommorrow in the light
Having re-inflated the tyres, one keeps going down - seems to be leaking between the tyre and the rim, not sure if the tyres just got dislodged on the rim a bit too much or whether I've damaged the rim whilst the tyres been deflated. The roads are so bad round here I wouldn't be surprised if I've bent the rim on a pot-hole - I do vaguely remember going over one that made me a bit worried a few days back, not sure now whether the tyres were inflated fully or not.
Oh well, will have a better look tommorrow in the light
PawnSacrifice - When you lower tyre pressure to truly low pressures (5psi) used in some aspects of the sport (ice, mud flotation, rock crawling) then you need to keep the bead on the rim. This is done by one of 2 methods a physical clamp that bolts the bead to the rim, called a beadlock, or in some case done with a specila inner tube that just hold the bead out agianst the rim. I suspec TG were using the latter
Siftah - 2 problems occur with tyres when driven deflated. The first is dirt gets in the mating faces between the tyre and bead. This then prevents a good seal when the tyre is reinflated. I don't suspect this as you drove on cleanish snow and ice. I have to remove my Jeeps tyres or break the beads after an event and clean these faces
The most likely is physical damage to the rim or tyre bead since you effectivly drove with the rim running on solid rubber in contact with the ground. I'd check all the rims surfaces inside and outside and if you cant see the problem lay the wheel on its face (protect it) then back and fill the bead/tyre gap with water to see any bubbles.
Expensive learning curve :thumbsdown:
Siftah - 2 problems occur with tyres when driven deflated. The first is dirt gets in the mating faces between the tyre and bead. This then prevents a good seal when the tyre is reinflated. I don't suspect this as you drove on cleanish snow and ice. I have to remove my Jeeps tyres or break the beads after an event and clean these faces
The most likely is physical damage to the rim or tyre bead since you effectivly drove with the rim running on solid rubber in contact with the ground. I'd check all the rims surfaces inside and outside and if you cant see the problem lay the wheel on its face (protect it) then back and fill the bead/tyre gap with water to see any bubbles.
Expensive learning curve :thumbsdown:
cj10jeeper said:
This is possible - the snow is mostly slush at the moment, thick black nasty stuff (I work on an industrial estate) so that's a fairly good possibility...
cj10jeeper said:
I'll give that a try tommorrow in the light, it's quite easy to feel where the air is leaking and it seems to be a section of about 6 to 8 inches along the front face of the rim. That's leading me to believe it's a pot-hole sized section but hopefully I'm just worrying about nothing
Expensive learning curve indeed!
2 things to try:
Overinflate the tyre to about 40 psi to seat it fully then back off to normal 31 ish
Jack up the car and spin the wheel with a fixed object near to it. (not a screwdriver or something scratchy, say a pencil) you'll easily see if the wheel is distorted enough to cause a seating problem.
Overinflate the tyre to about 40 psi to seat it fully then back off to normal 31 ish
Jack up the car and spin the wheel with a fixed object near to it. (not a screwdriver or something scratchy, say a pencil) you'll easily see if the wheel is distorted enough to cause a seating problem.
cj10jeeper, thanks 
Something I wonder about every time I see that episode!
Siftah, damn, that's bad luck / turn of events... hope it's nothing too serious!
Something I wonder about every time I see that episode!Siftah, damn, that's bad luck / turn of events... hope it's nothing too serious!
so my first accidental sideways action happened on the motorway last night.
this snow is getting really bad!
i was driving up the a1 from the angel of the north, nothing silly or fast but nice careful driving and my car suddenly decided it wanted to try and reverse home. luckily i wasnt close to any other cars on the road and i managed to control it (becasue iv been practicing
) but jesus christ! there was no need for the heated seats to be on lets just put it that way!
careful driving guys
this snow is getting really bad!
i was driving up the a1 from the angel of the north, nothing silly or fast but nice careful driving and my car suddenly decided it wanted to try and reverse home. luckily i wasnt close to any other cars on the road and i managed to control it (becasue iv been practicing
) but jesus christ! there was no need for the heated seats to be on lets just put it that way!careful driving guys
Rudd_2002 said:careful driving guys
Eek! Have had this happen to me in a Mini a few years back - that didn't have heated seats, until that incident!
Glad you're OK and even more importantly, glad the Z's OK too!
(My own Z's been resting on the driveway under a blanket of snow for the last couple of days, tyres seem to be fine so I think I dodged a bullet there.)
Safe driving all.
Took me just over an hour to do a 20 minute journey last night home from Oxford, snow was just starting to settle so fortunate that I left when I did but anything over 20Mph and the back of car started slipping out. Was very suprised that there was hardly any gritted roads, guess we'd better get used to it. After that experience I'm not taking it anywhere till the snows gone, which means snow day for me.
Slightly controversial question but does anyone know if a TT Quattro is any good in this kind of weather?
Slightly controversial question but does anyone know if a TT Quattro is any good in this kind of weather?
MrGringo said:
It will be slightly better at pulling away as you've more of a chance of 1 of the 4 wheels having enough traction.
It's got fat sports tyres though, like the Z4, so you'll still struggle for grip once you're moving.
Lots of weight in the boot, let some air out of the tyres, cross your fingers - snow chains or snow socks are best
south yorkshire
ttis awsome in the snow- ian g has one and itt has been all over in the snow- including bringing me home from work when the z got stuck!
This is what the Zed can do in the snow
[youtube]<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/AGOBlm51rQc&hl=en_GB&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/AGOBlm51rQc&hl=en_GB&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/youtube]
[youtube]<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/AGOBlm51rQc&hl=en_GB&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/AGOBlm51rQc&hl=en_GB&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/youtube]