Tyre Pressure Sensor driving me batty!

[Denc]

Hello - fist time here on what looks to be a great forum.

I have recently returned to Mercedes after a long spell of company supplied other-makes and generally glad to be back!

However the W169 A Class that I bought (2 years old) is driving me to distraction in the tyre pressure department.

First the indicator came on and I found a rear with a 8psi loss, pumped tyre - two weeks later tyre indicator on - 7psi loss . This was now Friday night and my wife was due to take the car on a business trip so i (gasp) filled the tyre with Goop sealant ( i know people tut tut at this but it cured the problem ).

Two weeks later same thing happened to the other rear tyre (no visable screws in either and a very slow loss)..so used the rest of the Goop and both have been happily inflated for the past 4 months.

3 days ago I had 2 brand new front tyres fitted and this morning - Tyre pressure indicator on...one front shows 32 psi the other 38psi.

My thinking is that the fitter pumped each tyre to different pressure and the imbalance has set the TPI off? Sound feasible?

Otherwise the W169 steel wheels are the leakiest wheels I have come across in 40 years of driving hundreds of tyres bought and fitted.

In some ways I wish the TPI was not fitted as well....what do you think?

 

[Touche]

My first thought is... cracked wheels?

 

[AMGeed]

I think you can turn the sensors off with STAR. They do seem more trouble than they are worth.

 

[Denc]

I suspected that the wheels could be a problem - but they are steel. I suppose that doesn't rule out a faulty 'leaky' batch though.

I didn't know you could turn the indicator off - that might be an option as the majority of my trips are low speed and urban and if I do any long, higher speed journeys I check the tyres visually anyway...the TPS remains a nagging nuisance.

 

[Benzowner]

Did you reset the tyre pressure warning system after the new tyres were fitted?

 

[Alps]

I would point to wheels leaking air, then do a reset on the sensors.

Sensors are doing their job and warning you of pressure loss.

 

[davidsw]

Had a similar problem ..the tyre fitter did not clean the wheels properly before fitting new tyres. Removed tyres wire brushed the wheels applied some sealant or other ... problem solved. The slight leak did show up when wheel removed and put under water.

 

[Denc]

Hmm no - silly me I didn't reset the TPS after new tyres...I thought they went to sleep when you turned the ignition off and started checking again once car restarted. Thinking about it - if that was true then a warning would reset itself by restarting the car - which it obviously doesn't ...good point thanks!

Re cleaning the wheels - that could be true - I suppose before TPS we never noticed very slow leaks that much and so sealing against the tyre wasn't so much of an issue.