rennlistuser3

Hi Guys, need some help please.

The rear tires on my 2005 Boxter S with 19" lobsters keep on going flat. They went flat on me 4 times in the past year. At first I thought it was old tires, but just today I was astonished to see the fourth flat tire incident but this time with my new OEM Bridgstone N2 tires. I've had the rear rims themselves cleaned out previously in hope to fix this problem. Yet it prevails. There are no dents on the wheels. They're in good condition.

This is my first experience with low profile wide tires. Is this common? or am I having the worst of luck?

P.S. I do tend to keep my car parked for prolonged periods (in this case about 2 weeks)

Byprodriver

Try replacing the valves in the valve stems &/or nitrogen instead or air in the tires.

Schmidts Cat

Have your tire shop submerge them to check? How quickly do they lose pressure, and how much... Full flat?

fhp911

We need more details: Are they punctured, or has the air simply gotten out? Is it the same tire (ie, rear left) each time? Is the tire sliced or rubbed? Anything else weird?

sjfehr

Neighbor kids bleeding the air out, maybe?

djantlive

likely failed valve stem. Submerge in a water tub will point out the culprit. Sometimes it is a very slow leak.

cairo94507

If the car is not parked in a secure garage at night, I vote kids playing games.

fhp911

As I said in my earlier msg -- give us more facts.

rennlistuser3

They did so with the older tires. The didn't find a leak. I'm surprised because this happened with the new OEM tires.

rennlistuser3

No, not on any of the occasions before were the tires punctured. Just simply air getting out. Sometimes to the point of needing to reseal the tires before they can be inflated again.

It happened on both sides but happens more often on the passenger side. No slices, no rubs. The tires themselves look fine.

The wheels are also in good condition. I checked those as well awhile back.

rennlistuser3

Probably, I might replace those. I'm not sure if they were replaced when I had the new tires mounted.

rennlistuser3

Yeah, I'm sport of getting suspicious of this myself. The only reason I'm dismissing this is that I've never had the front tires deflate before. It sort of also makes me wonder if hard acceleration might cause the rear tires to lose air slowly and then eventually go flat. This is why I posted here. I thought the more experienced users would know if hard acceleration can cause the rear tires to lose pressure gradually and then go flat.

Macster

Porsche calls for at least the rear tires to rest for some time (I seem to recall 24 hours but don't quote me) after installation to avoid the risk of the tires spinning on the wheels. However, more than once I have picked up my cars before 24 hours have elapsed after having new rear tires installed and with no problems. 'course, I take it easy as the new tires need time to "break in", loose their greasiness before they develop their max. grip.

If one takes the car out too soon, and hammers on the car using hard acceleration, going around corners to aggressively, the rear tires can spin and then leak.

If you are sure the wheels have no porosity, the valve stems and valves inside the stems are air tight, and no one is letting the air out of the tires as a "prank" then I'd consider the rear tires, at least one, spinning on the wheel.

It is important the wheel, and this includes the rim where the tire bead seals, be in good shape. The tire may have to be removed and this area checked for any nick, gouge, or even a crack.

sjfehr

Spinning on the wheels will throw off tire balancing, but isn't going to cause pressure loss like this. It's also something more related to really wide grippy r-compound racing tires installed on really high horsepower cars, and with far too much lube to wrestle the stiff sidewalls. I've never heard of it occurring on stock wheels and street tires.

If it's happening with multiple tires than it's either the wheels, valve-stems (were they changed with the tires?), or a prank.

ZX9RCAM

Subscribed to find out cause.....