New Tires or Repair on an E90?

Kintarō Hattori

Hey Folks,

The missus has a 2005 E90 which has run flats. The two front tires seem to be A-OK but the two rears always lose air quickly after being pumped up at the station. I spoke with her mechanic and asked him to quote me for two new 16" Bridgestones tires. Fitted it'd be €240 which is fine.
However she's been told in work that a mechanic should be able to repair the tire for a fraction of the cost by repairing the puncture. Is this possible, is it safe (I wouldn't have thought so)?

I favour the new tires as it'd presumably be a lot safer but if it's a possibility I guess it needs to be looked at.

Many thanks.

punisher5112

Are we talking about a screw or nail or the valve?

If its something small a repair would be fine but a tyre centre will know or mechanic.
If its in or very near the side wall of the tyre then it's new that's needed.

If it's the valve just get it replaced and that should solve it.

If it is a bad tear I would reommend new tyres.

porsche boy

Their runflats and not recommended to be repaired. Replacement is the way forward.
When the tyres are driven on with low or no pressure it is the two sidewalls that support the weight of the car and being driven on will lead to separation or rupturing of the sidewalls internally, you will not see this damage unless you xray the tyre, seriously. A damaged sidewall can blow out when the friction of the tyre on the road heats up the rubber. Thats why blowouts occur more on motorways then whe the car is sitting in your driveway.
For safety's sake replace them.
I have sold sets of non runflat tyres to owners who replace the runflats with standard tyres and source a space saver spare wheel from BMW or a breakers yard. The cost of replacement standard tyres is lower than their runflat equivalent.

Avns1s

A runflat tyre can have a puncture repaired, just the same as a non run flat tyre, PROVIDED it hasn't been driven flat!

nc19

It is not recommended to repair run flat tyres as the mechanic has no way of knowing how long the tyre has been driven on flat for. Run flat tyres have a rigid sidewall so even with no air in them they look inflated. Being driven on in this condition leads to immense amounts of heat in the sidewall which can cause catastrophic damage some of which is only seen through xray.
Obviously, if I was certain the tyre was only recently punctured and not driven on for long then I would consider a repair depending on the overall condition of the tyre.

In your case OP I would suggest that it may be the bead that is leaking due to corrosion and a bit of bead sealer may solve the problem.

Avns1s

nc19 wrote: »

In your case OP I would suggest that it may be the bead that is leaking due to corrosion and a bit of bead sealer may solve the problem.

Or perhaps cracked alloys?

btkm8unsl0w5r4

Kintarō Hattori wrote: »

but the two rears always lose air quickly after being pumped up at the station.

Unlikely that you ahve two punctures. Maybe a cracked alloy, faulty valve?

Kintarō Hattori

It does seem odd alright that both aren't quite 100%. While my preference would have been to replace both wheels, based on the insightful replies given I think the best thing to do is for her to drop them into our mechanic.

Thanks everyone.

Alanstrainor

Is the car on original alloys? I'd want to know where the cause of the flat for certain. Not much point replacing tires if the wheel is cracked or losing air in some way.

biko

I'd start by swapping out the valves. Costs is next to nothing.

Avns1s

Alanstrainor wrote: »

Is the car on original alloys? I'd want to know where the cause of the flat for certain. Not much point replacing tires if the wheel is cracked or losing air in some way.

So would I (want to know). And it's a very simple thing to do, if the tyres are losing pressure at the rate the OP mentions.

Checking the valve stem on its own is even easier. Rotate to bottom and put on a little water with Wash up Liquid mixed in. (Or go the old fashioned route and apply an accurate spit!! :) )

Kintarō Hattori

Alanstrainor wrote: »

Is the car on original alloys? I'd want to know where the cause of the flat for certain. Not much point replacing tires if the wheel is cracked or losing air in some way.

It is indeed on original alloys. Will see if I can check the valves when I get home.

Kintarō Hattori

So she (the car) got some new rear shoes last night. Turns out the tyres were almost bald. The mechanic inspected the wheels and valves but couldn't see anything wrong. His opinion is that they probably had a slow puncture due to the lack of thread on the tyres.