Problem with tpms?

You could test out the system with a bartec 400.

But before getting too expensive. Check with a gauge and check if you have any leaks with soapy water. But I will tell you one thing. The bartec 400sd is one amazing machine

Madevilz wrote: ↑ I had my summer tires put back 2 weeks ago at Costco, pressure was fine, today the rear driver side tire had a sudden loss of pressure (like 8 psi). Inflated it back up. Came back home, hours later, the rear passenger side lost pressure, went from 36 to 24, I was really puzzled. The tire didnt look flat at all. I used a tire gauge to make sure the tpms was right and it was. I did hear a weird electrical sound from the tires, it wasnt the sound of air leaking, first time I heard such noise, then it stopped after about a min. This is really weird to me. Im almost positive its not a flat. The driver side did not lose pressure since I inflated it back up. Could it be a problem with the sensors?

Given that you double checked with a tire gauge, it's doubtful that the sensor is inaccurate. You'd be surprised at how similar various PSIs look, which makes visual inspection of tires to only really be useful if there is a fairly significant variance in tire pressure. Your tire is either leaking air itself, or you have a cracked rim which is causing your set up to lose air pressure. If you can, do a visual inspection inside your wheels to see if there are any imperfections that could be causing air to leak. If you still can't find anything, probably best to take it to a tire and rim shop and have them take a look. Most places will do a free inspection for you, and then try to sell you a replacement or fix while your car is already hoisted. Good luck!

Something is leaking. Could be the sensor, tire, or wheel. We can't tell you which. Someone's gotta check.

Too much unknown to diagnose.
Were your summer tires already mounted on dedicated rims or did Costco remove the winter tires from your rims and put your summer tires on same rims?
What model and year of vehicle?
How old is your vehicle?
Does your vehicle have a load leveller?
Are the TPMS sensors original and/or do you know how old they are?
Can you program the TPMS sensors without a programming tool?
Is the pressure of each tire indicated on your instrument panel?
Are your winter tires/wheels still in the vehicle?

CaptSmethwick wrote: ↑ Too much unknown to diagnose.
Were your summer tires already mounted on dedicated rims or did Costco remove the winter tires from your rims and put your summer tires on same rims? Yes, already mounted, I manually tested the pressure with a gauge prior to having them put back on my car and all read about 34-35 PSI, so if one leaked during the winter, it would have been different than the others
What model and year of vehicle? Ford Fusion Energi 2017
How old is your vehicle? 3 yo
Does your vehicle have a load leveller? no
Are the TPMS sensors original and/or do you know how old they are? yes, came with car
Can you program the TPMS sensors without a programming tool? I know pretty much nothing about TPMS, this is my first time having one, my guess would be no
Is the pressure of each tire indicated on your instrument panel? yes
Are your winter tires/wheels still in the vehicle? no

Answer in bold
I checked this morning, pressure all ok, same as I left it last night.
How can a leak make the pressure go from 36 to 24 within hours, and then be just fine this morning?
Is there even a possibility that I had a false reading and that I over inflated my tires?

Could be a stuck valve stem core.

vlad353 wrote: ↑ Could be a stuck valve stem core.

Maybe, last night when I tested manually, I did hear air still leaking as I was pulling out the gauge, it lasted a few sec. Could have still been leaking air after the first time I tested earlier in the day but I didnt hear... sounds a bit more logical than a faulty tpms.

Happened to me with an OEM TPMS valve, it would be fine until I checked the pressure with a gauge, it would leak sometimes quickly within hours, other times slowly in days. If I don't touch it then it would be fine for months. Finally replaced it with a sstandard rubber valve, no more leaks. I stop replacing TPMS valves even if my cars have the system, I'd rather check the pressure myself like we all used to do before TPMS became "standard".

Yours could be the TPMS valve being defective but intermittently.

gumby wrote: ↑ Happened to me with an OEM TPMS valve, it would be fine until I checked the pressure with a gauge, it would leak sometimes quickly within hours, other times slowly in days. If I don't touch it then it would be fine for months. Finally replaced it with a sstandard rubber valve, no more leaks. I stop replacing TPMS valves even if my cars have the system, I'd rather check the pressure myself like we all used to do before TPMS became "standard".

Yours could be the TPMS valve being defective but intermittently.

Thanks, i'll monitor it in the next few days.
It's a useful system, but just like you, I'd rather check it manually, so i'll change it to normal valves if it indeed defective.
The only thing bothering me was the warning light that comes up when there are no sensors as with my winter tires.

Madevilz wrote: ↑ Thanks, i'll monitor it in the next few days.
It's a useful system, but just like you, I'd rather check it manually, so i'll change it to normal valves if it indeed defective.
The only thing bothering me was the warning light that comes up when there are no sensors as with my winter tires.

You put up with the winter tires for 5-6 months but not the A/S tires for the other half of the year? I learned to live with the TPMS warning light year round now
BTW, TPMS is not mandatory in Canada so it's up to the owner.
https://www.tc.gc.ca/en/services/road/v ... itors.html
https://canadasafetycouncil.org/tire-safety/

tmkf_patryk wrote: ↑ You could test out the system with a bartec 400.

But before getting too expensive. Check with a gauge and check if you have any leaks with soapy water. But I will tell you one thing. The bartec 400sd is one amazing machine

Can you explain how to check a tire (on a vehicle) with soapy water?

Marzipan wrote: ↑ Can you explain how to check a tire (on a vehicle) with soapy water?

You spray the soap on the entire tire, if there is an air leak, you will see the soap bubbling up.

Madevilz wrote: ↑ You spray the soap on the entire tire, if there is an air leak, you will see the soap bubbling up.

So jack up the wheel and take it off ... I was thinking it was a quick in-place test.

Madevilz wrote: ↑ How can a leak make the pressure go from 36 to 24 within hours, and then be just fine this morning?

Did you move the car? If you have a small nail or screw in the tire, the amount of the leak can vary drastically depending on where the nail is when the tire is parked. Sometimes almost nothing leaks and sometimes air will gush out depending on the position.

100OceanSpray wrote: ↑ Did you move the car? If you have a small nail or screw in the tire, the amount of the leak can vary drastically depending on where the nail is when the tire is parked. Sometimes almost nothing leaks and sometimes air will gush out depending on the position.

I moved the car just a bit in my driveway to see if there are any changes.
So far, no change in pressure from last night after I drove to the gas station to pump air.

Madevilz wrote: ↑ I had my summer tires put back 2 weeks ago at Costco, pressure was fine, today the rear driver side tire had a sudden loss of pressure (like 8 psi). Inflated it back up. Came back home, hours later, the rear passenger side lost pressure, went from 36 to 24, I was really puzzled. The tire didnt look flat at all. I used a tire gauge to make sure the tpms was right and it was. I did hear a weird electrical sound from the tires, it wasnt the sound of air leaking, first time I heard such noise, then it stopped after about a min. This is really weird to me. Im almost positive its not a flat. The driver side did not lose pressure since I inflated it back up. Could it be a problem with the sensors?

Just a heads up, radial tyres don't need to "look flat" to be low on air. Considering radial tyres have been in widespread use since the 80s, this has been the case for decades.

Anyway obv. you have air leaking somewhere, just take to a tyre shop and get fixed. They will find where the air is leaking from pretty quickly and do the correct repair (or tell you you have to replace, if that turns out being the case).

Marzipan wrote: ↑ So jack up the wheel and take it off ... I was thinking it was a quick in-place test.

Usually, there's no need to remove the wheel. You can put an inch of dish soap in an empty spritz bottle (we use a Windex bottle), fill the rest with water and spray away. Start with the valve, since it's easy and often the problem. Do the exposed portion of the tire and look for leaks. If none, roll the car forward a foot or 2 and try again. It's easy to cover all but the inside of the tire, but that's rarely where damage would be.

Okay. That gives me a fuller picture. Basically, if the tpms are accurately showing a pressure loss, then you have a leak. There are so many places where a tire can leak air so, yes, you will have to do the soap water test if it's a slow leak. My father had a persistent leak in his tires. It turns out that the tires he bought were very old stock when sold to him and by the time they were leaking, they were almost 10 years old. Valve stems deteriorate. You get road hazards and the bead's seal against the rim can weaken. This is a cheap service at a tire shop if spraying soapy water doesn't help.

Good luck!

CaptSmethwick wrote: ↑ Okay. That gives me a fuller picture. Basically, if the tpms are accurately showing a pressure loss, then you have a leak. There are so many places where a tire can leak air so, yes, you will have to do the soap water test if it's a slow leak. My father had a persistent leak in his tires. It turns out that the tires he bought were very old stock when sold to him and by the time they were leaking, they were almost 10 years old. Valve stems deteriorate. You get road hazards and the bead's seal against the rim can weaken. This is a cheap service at a tire shop if spraying soapy water doesn't help.

Good luck!

I tried the soap yesterday on the driver's side tire, doesnt look like there is air leaking at the outter visible part. Didnt test the passenger side as it was raining the whole day. I drove around a bit, and no air loss since yesterday, surprising since the passenger side lost pressure so quick.

Gonna monitor the pressure over the next couple of days. Will have the tires checked out at the first sign of air loss.

Is Costco a reliable place to have the tires checked? Or should I go to a place specialised in tires?