Leaking FRONT tires

I own a 2006 Kia Optima that I bought just over a year ago, slightly used, with 12,000 miles on it. The car has aluminum rims and “low profile” tires: 16 inch—205/55/16. As far as I know, the tires were original to the car.

For some time now, I’ve been experiencing slow leaks in the front and ONLY the front tires–both of them. The rear tires have never leaked. A few months ago, I rotated the tires, front to back/back to front. The tires that had been leaking (that were originally on the front), once moved to the back, CEASED to leak. But the tires that had been on the back, and had never leaked, began to leak once they were moved to the front.

I’ve carried on adding air to the tires, checking the pressure—and always it’s the tires on the front that leak. Never the rear. Finally, almost exactly two weeks apart, both front tires experienced sudden and total deflation while I was driving (and were quickly ruined, so I had to purchase used tires, temporarily, not having the cash just now to spring for all-new tires). Thus far the used tires I purchased have not leaked. But I can only assume that it’ll just be a matter of time.

Can ANYONE tell me what the hell is going on here? I’m thinking it must be the turning and cornering, and perhaps the occasional bump, which the front tires take the brunt of… but don’t really know. Does anyone have any thoughts?

Have you checked with a dealer to ensure those low profile tires are OEM? For that matter, what does your owners manual specify?

Usually those tires come OEM on high performance vehicles.

The weight difference at the front could be making those tires flex or the (aluminum (alloys?) rims flex enough to cause a bead leak when the vehicle is in motion.

This will happen when the alloys start to pit too.

Well, let’s back up a bit. Everyone CALLS them “low profile” tires, but they don’t look all that low profile to me… certainly nowhere near the ugly low profile tires you see on some cars, where it’s all rim and appears to be almost no tire. So maybe I’m wrong to call them “low profile.”

At any rate, I’m almost certain these were OEM–they’re the right name brand. I don’t have the owner’s manual handy just now to verify this though.

I think it’s too soon for the alloys to be pitting, but your thought about the weight sounds sensible. But thus far I’ve never heard of another Kia Optima owner who’s had the same problem.

Don’t assume it is the tyres leaking. Those fancy rims have a real reputation for leaks and damage. There is more weight and stress on the front so I would tend to believe that it may open up a tinny crack in the rim and the back may not.

Thanks Joseph… I see you’re a Brit (tyres). Do they have Kias in the UK? I didn’t know they were selling them in Europe.

Anyway, only problem with your theory is—I rotated the tires, rims and all, from front to back/back to front. The leaking ceased when the tires were moved to the back… and the tires that had been on the back began to leak once they were on the front… YET… the tires that are now on the back have NEVER leaked since they’ve been back there… if you follow me.

But maybe it’s an issue of stress, as you say–and rather than tiny cracks, it’s that the rims on the front warp a little and the bead gets broken?

I’d definitely call a 55 aspect ratio a low profile. Me, I have 45 aspect ratio tires, but mine aren’t ugly!

Seriously, slow leaks can best be found by removing the wheels, pressurizing the tires to the maximum on the sidewall, dropping them into a child’s plastic pool full of water, and sitting back with a cool brew watching for bubbles.

Common sources of leaks are valves (some folks don’t put new valves on when swapping tires), corroded alloys with porosity (Ford used to have a big problem with this), and tires that have been repeatedly swapped off and on the rims with the changes of the season…snows on in winter, summers on in spring. That beats up the beads and the rims both.

Yeah, the average FWD car has about a 60/40 weight distribution front vs. rear. That means there’s 50% more weight on the front wheels. That could exascerbate a slow leak.

as another thought…

most autos have a front and rear tire pressure (which is different for both.) are you sure (not to be a doubting thomas) that you have the pressure correct? with a tire gauge? with the pressure on the front and rear tires recorded?

Yes, pressure has always been correct. Checked repeatedly with a tire gauge.

Yeah, more weight on the fronts and on top of that, when you brake, car “dives”- front goes down, rear goes up; making it more like 70/30- but to make fronts go FLAT WHILE YOU’RE DRIVING? Someone’s gotta be deflating your front tires. If they let a lot out of one tire but not enough so it was actually flat the added rolling friction maybe could’ve destroyed that tire, but geez, I’m grabbin’ at straws here.

Randall1001- how much do they leak over what period of time when they’re not actually going totally flat? This is very iomportant. Shouldn’t car still be under warranty even though you got it used? A certified used car warranty at the very least. My point is, have you called the dealer to see if there are any tsb’s for this condition? Can’t hurt to call. Please post back- this is baffling. P.S:

Check all 4 tire pressures 3 times a day and record for posterity; I mean, if pressures are ok at night and low next AM (taking into account temperature change) you have a vandal. Quantify the situation- help you get a handle on this Agatha Christie.