And you will eventually need new tyres, at which point you will remember that garage that didn’t rip you off last year. Or you’ll send your neighbour there when they have an issue. Goodwill is priceless for small businesses.
As I understand it, the gold standard is a patch and a plug. The plug stabilizes the edge of the hole and the patch provides the seal.
That said, I’ve used the kits with the reamer, the sticky ropes and the vulcanizing glue on motorcycle tires with great success too.
The “drive” tire?
My first car, a VW Beetle, had rims made of putty. I’d hit a pothole and bend a rim enough to get a flat. I carried a ball peen hammer. Jack up the car, fix the rim, then use my compressor to refill the tire and I was good to go.
My Jeep’s horn hasn’t worked for 8 years. Hasn’t been noticed in a yearly state inspection yet, which is sad.
It is. Sorta sideswiped the stone birdbath backing up. The first go-round of repairing it with touch-up paint was pretty bad so I sanded that away and used matching spray paint and clear coat so it went from laughably bad to pretty damn decent. I almost wish I had used some body filler and sanded it smooth yet I’ve seen the work of incredible body shop guys and know that I’ve not that kind of talent. Me and the 100+ year old birdbath that outweighs me have made peace.
It also reminds me that I had no leaking tire at the time so my working cause is a sloppy work guy keeps dropping screws in a parking lot - even if he could strew the lot with broken glass and thumb-tacks and 99/100 times I’d not get one stuck in the tire. It’ll be a tough case even if it’s the same exact screw I showed the foreman a few months ago and mentioned I had a (then slow) leak. Right now I’m flummoxed over the cause and why I didn’t find it a few months ago and no bubbles or visible anything today.
My confusion between positraction/limit slip differentials and open differentials as applied to FWD cars. I thought that one tire gets “most” of the power from the differential. I guess I just don’t want one tire to have more of a grip profile which is why I’d prefer to patch & plug this still good four year old tire rather than get just one new one. If I’m buying a used car and there’s a Pirelli on one side and a Dunlop on the other and there’s 9mm if tread on one and 7mm on the other it’ll raise some questions and doubt. That said, if it doesn’t matter and there’s no decent used low-budget Ovation tires available (probably salvaged from a wreck) then sure, one new whatever tire mounted & balanced will quite do as screw or valve or whatever, this tire is done for.
Tires Plus (owned by Firestone) not only told me they wouldn’t patch it (without looking at it) but told me I needed all four new tires (again, w/o ever coming out from behind the counter) because the AWD sensors wouldn’t work properly if the tires had different diameters due to one having more tread life than the other three. That’s very sound logic if I had AWD & not the front wheel drive that the car has.
I took it around the corner & a local tire shop patched it; that patch lasted over a year, until I got new shoes all around due to tread wear.
On a separate occasion, I put new Firestone’s on & when they called me to tell me it was done it was magically $300 more than when it when in because they somehow couldn’t honor the price. 
When I said no deal, he ‘checked with the manager’ & said they’d split it with me - $100 less (ummm shouldn’t that be $150?) but I had to pay for it on their CC, which means they got credit for opening a new account. Weaselly bastards had to change the tires again as I went home on my original rubber…& the Goodyears I have now are very good, TYVM
Personally I’d just get a new tyre, and if there’s still an issue then have the wheel checked.
Basic no-name tyres are dirt cheap, including fitting. And I’m not saying that to sound snobbish but I mean within the context of running a car, where at any time some mystery thing happens to your clutch and suddenly you have a $2000 bill. You could buy 4 new sets of budget tyres several times over for that.
At some point I need to be able to take off the lug nuts in case of a full flat tire. I was looking at wrench extenders and even breaker bars to get the leverage I need. I’ll see if the work guys - especially the foreman come around tomorrow. He’s got a full kit of Stanley. If I can get the tire off I can do a better inspection of what should be obvious: blowing bubbles through soap and/or hissing.
But yeah, it’s gotta go to the tire place and I’ll leave it to them whether it’s patchable or a new tire is called for.
£2000 clutch jobs on a £1200 car are off the table. I’m sure the garage in Bath could rack up £800 in specious problems but now we’re further south and lo! I just found out my MOT (inspection) expired 3 days ago. So £55.85 if it’s squeaky clean. I really thought I had till next year. I can’t afford any fixes outside of this tire till the end of the month. I’m naive enough to think if I explain my money situation and they do the tire work they won’t be finding undercarriage rust (£400) or springs in need of replacement (£400) or imaginary leaking power steering / oil / headlight fluid I can get through this for about £120. Over £500 takes the car off the road and just like the Nissan Micra sold to some guy with a welding setup and a friend who will pass his MOT for a little kickback.
I think we’ve a lot in common. I’m driving a 2005 Volvo. Cost me £1500. And I’ve had at least one garage try to charge me the value of the car because of a supposed undercarriage oil leak. Luckily I had a friend with a big jack and we did our own inspection and it was fine. That was maybe a year ago and I’ve never seen a drop of oil on a parking spot.
But last time I needed a tyre change it was only £50 for an arrowspeed. As it was so cheap, and they said there were other tyres to “keep an eye on” I just bought a whole set.
I wouldn’t like to drive on a tyre that is losing air that fast. Not to alarm you but they can also be a blowout risk.
It’s next drive will be to the garage. Maybe not the tire place I had in mind but the other general garage, even though I’m sure both can do MOT’s and tires. With a little luck any problems are just warnings/advisories and I have a safe tire as well…
In New York I had a friend who was a mechanic. Sure, he’d check the car was okay yet didn’t have a mandate to fail me on the flux capacitor to make up the difference between mechanic hourly rate and inspection cost (I think in NY at the time they cost like $25 or about a third of a mechanic hour). One time he nonchalantly used the output of my exhaust to pass another car’s CO reading so perhaps not entirely ethical or legal.
But that’s long ago & far away. In the UK I have no friends with ramps or hydraulic jacks to “pre-inspect” the car or access to a junkyard where I can bring my tools and crawl around and find stuff I need. Heck, me and my brother installed an (auto) transmission in my Monte Carlo with ramps and a sliding jack. And due to Chevy’s brilliance in putting the starter right whete the two exhaust manifolds meet and toasting the starter, at least eight starters. From jacking it up, replacing it I got that down to less than 10 minutes. It’d take me that long to even find the starter if this car was up on a lift. It’s probably tiny for a 1 liter engine compared to a 5.8 liter V8.
On two occasions I’ve found my slow leak to be due to a rusted wheel rim. $16 for a new-to-me intact non-rusted rim at a junkyard both times, plus a bit for a mechanic to do the swap.
But, seriously - if you’re losing 15 psi a day your vehicle is NOT safe to drive. Limp slowly to a repair shop and get it fixed, even if you have to borrow money to do so.
Very good input so far. I’ll just add a couple comments:
Small shops usually like to fix flats. It’s basically all profit, since the materials to do the job are minimal. Their water tubs, air wrenches, tire mounting equipment, etc., are just sitting around otherwise. I used to jokingly accuse the owner of my corner garage of sprinkling nails around the neighborhood. He’d tell me it was a good week when houses were under construction nearby, or when a crew was replacing a shingle roof. He hardly ever replaced tires…just plugged and patched them.
I’ve fixed a surprising number of tire leaks by replacing the valve core. It’s easy to diagnose and the tool to do it is usually less than $8. It’s not the most LIKELY cause of the problem, but it’s the easiest to fix yourself.
If you do find a foreign object or puncture in your tire in the tread area (not sidewall), plugging a tire yourself is also pretty easy and inexpensive. There are plenty of YTs to show you how. You usually don’t even have to take the wheel off the car. A plug can last for the remaining life of the tire.
Not relevant to the OP’s issue, but my current set of snow tires has one that started leaked very slowly the winter before last, losing 8 to 10 psi over the course of a week or so. Two trips to my local auto mechanic and they couldn’t find anything. I began to suspect the problem was a bit of grit might have gotten into the valve core in just the wrong place to mess the seal, so I bought a package of replacement cores. While I was getting those, there were replacement valve stem caps made from metal hanging beside them, so I bought a package of those as well.
When I got home I replaced the original plastic valve stem caps with the new metal ones on all 4 snow tires. The very slow leak stopped happening. My conclusion was that the tighter fitting new valve stem caps provided enough of a seal that the air leaking through the valve core was retained by the cap. I still got the auto shop to replace all 4 valve cores the next spring and there’s been no issue since.
I have a bicycle tire valve stem cap saved from my old 10-speed that has the two-pronged extension for removing valve stems built into it. I could have bought a package of 4 of the same types of caps, but they didn’t have the anodized black finish.
Nice!
If I run into a slow leak, the first thing I do is pour a cup of soapy water over the stem (with the cap removed). Next, I pour a cup of soapy water at the top of the bead so it runs down the entire bead of the tire (both sides).
I usually also pump the tire up to about 125% of its normal pressure (say, 40 PSI if the norm is 32 PSI). Speeds things up a bit.
I’ve used the same Tire shop for decades. I buy tires for several family vehicles.
They know me and getting a flat patched for $20 is routine. There was one time glass had gashed the tire and it needed replacing. They showed me the damage.
I did a really close flash-light & magnifying glass check of the tire back in summer (procrastinate much?) when I noticed it was noticeably low/flatter. It was about 19 PSI and the others were around 27-28 so I topped all round to 30. Back then, outside of occasional longer trips it was not a daily driver. Last couple months I make about 8 round trips a week to drop off/pick up my wife for only about 24 miles a week and last month I noticed it would drop to about 22 in a day, then perhaps 16 in two days and I’d top it up even if not driving that day. A couple more flash-light inspections of the treads and inside wall showed nothing. The soapy suds yesterday also showed nothing and it was also my intention to pull the tire yesterday, pop on the donut, inspect the tire and roll it down the block to the shop. The torque on the lug nuts was way more than the lame socket wrench that comes with the car. I figured I would want to have a 17mm wrench and an extender…
Now that I see it’s a few days past due for a MOT, I’m just going to let the shop handle both and hope for a clean pass, patched or new tire and that it’s not a defective rim. Last year the car (previous owner) failed on one tire (less than 1.6mm) and had an advisory for another so all four tires - if not new (I thought 2020) - were put on to pass it. A brake cylinder also had to be fixed. No advisories for things like rust and springs that have been my bane with MOTs these past few years. The passenger side headlight is a bit less clear yet I hope that falls into advisory as at night you see the same amount of light. If that fails the MOT I hope they can at least match eBay for the part - approx £70 - and I’ve no idea about time/labour yet I’ll wager some special tools are needed to take this project out of DIY reach.
If I can pass clean or just some advisories and get the MOT and tire repaired for less than £150 I’m golden.
Last year my gf’s Silverado told her a tire was low. I checked and topped off all four tires, but the truck still says one (passenger front) is low. Recently it told her a rear tire is low. Again I checked and all are fine.
Some “tire pressure” sensors work by detecting a difference in tire RPM, not actually measuring the PSI inside the tire. The thought being that a flattish tire will have a smaller effective diameter and hence spin faster than the others. Average that out over a bunch of miles then sound an alert if one tire is an outlier.
Such a system can confuse uneven tread wear for mis-inflation. you might want to look at your tread depth as well.
They will give you a hard time or even refuse to patch your tire if your tread is low.
Ten years ago I was going to mow the lawn for the first time in the spring. I noticed our Kubota had a flat front tire. My gf wanted me to order a new tire immediately, she didn’t want the grass getting ahead of us… Instead I inflated the tire, found and removed the nail, then put a plug in the hole.
My gf was livid, saying my patch would never last and I was being foolish/cheap.
Well, ten years have passed and the tire is still doing well. A replacement would have been $150.