I've never had a car with alloy wheels before.  New tires, in about 2-3 months, they loose significant amount of air.  My almost 30 year old steel wheels on my older wagons hold air a lot longer.

 

I will have to check the stems, etc. with soapy water, but is there anything I should know about particular to alloy wheels?  2 of them leak down faster than the other 2.

 

Also, related, the car has tire pressure warning light.  It seems to be complaining now, even after I aired the tires back up.

 

 

Alloy wheels are more porous than steel.

Not a permanent fix but the tires can be removed, wire wheeled, sealed then remounted.

Can't answer the tpms issue.

 

O.

davet,

 

Over the years I've had a mag wheel or two lose air much quicker than the others on the car. I had the tires removed from the wheels and then refinished the wheels, being sure to paint well the interior of the wheels (where a rubber tube would be on a tubed tire) as well as the tire bead surface. Never had any more issue.

ok, sounds like I have another project...

 

I have to find an extra matching wheel to make this practical .

With my alloys, I check air pressure the first of each month, and generally need to add a little air. Alloys also rust around the tire bead, which causes the tire to loose air. When that happens, the tire needs to be taken off, the wheel bead cleaned, and sealer added to the bead to create a good seal.

 

Alloy wheels don't tighten up well upon put upon a car. Drive 20+ miles, then re-tighten the lugs. Chances are, you will find the lugs do need tightening.

 

Avoid hitting pot holes with alloys and low profile tires. Just too easy to not only blow a tire, but to break an alloy, requiring wheel replacement.

Are there any steel wheels that would fit? Preferably similar size? It came with Subaru wheels as far as I know. They are not obviously low profile tires.

Suggest you call, or email tire stores that sell wheels..... companies like Discount Tire or Tire Rack. com. They like to sell expensive alloys wheels with lots of bling, but also sell steel wheels most likely for both highway and off road use. Ask them what size wheel will fit your Forester. Write down the size(s) including wheel offset, and lug nut arrangement. Once you learn the sizing, you should be able to find some good steel wheels at a wrecking yard for cheap. Would also be a good idea to call wrecking yards,or email them to ask what steel wheels they have available that would fit your Forester. It can be surprising to learn how much the yard guys know about what parts they have, and what will interchange with other cars.

Subaru made the basic Forester steel wheel in 16 and 17", and for several years. Shouldn't be hard to find.

Unfortunate part about alloy wheels is they're easy to gouge. I've seen many an alloy wheel with large gouges from tire tools in the area where the bead of the tire seats against the rim. That causes a poor seal, and also exposes bare aluminum which corrodes in short order.

 

Another issue I've found with newer tires, is the placement of a small barcode sticker on the bead of the tire. I assume the stickers are for manufacturing purposes, but they always put these stickers on in the worst possible place and it's usually crooked, in a spot where it gets between the bead and the rim of the tire. It causes a leak, even on a totally clean wheel. The stickers are incredibly hard to remove, dunno what kind of adhesive they use on them.

I've had to use bead sealer on quite a few tires just because of those little stickers.

 

Use some soapy water to find your leak and mark both the tire and the rim with a grease pen or marker so you can easily identify the problem once the tire is dismounted.