ML 166 Tyre Pressure Sensor

[ThinkPad]

Evening all,
ML 166, 350 Deisel 2014.

One tyre has been leaking air for a while and I fill up and probably 2-3 weeks later it requires another top up. I did notice it is difficult to attach the hose to fill up so I suspected it may be issue with the valve.

Today I woke up to the other rear corner with a significant loss of pressure.

Went to local tyre shop who said that the valve is fault on the one which I have been filling for a couple of months. Probably the same issue on the other (despite the sudden loss)...

I have been advised to 'look online' and buy a set of 4 valves with the pressure sensors built in and return to this chap...does this sound about right?

I have had a quick search on eBay but looks like I will very easily buy the wrong part, so may just wait until MB parts are open and order from them.

On another note, also woke up today to the car running rough! Restarted it and it was fine...very strange. Christmas must be playing havoc with the car. Haven't had a single other issue with this car since purchase around 15 months ago !

 

[mioba]

Would not bother with ebay parts. Best bet wait for the dealer or even go the dealer and get it all done there.
Did your tyre place take the wheel off and inspect it/put it in a bucket.

Regarding the rough running, funnily I had this once with my W251 (same engine I am sure), started it one morning and it felt like it was shaking the house down. Switched off, then back on and all fine ever since (touch wood)

 

[EmilysDad]

.....

I have been advised to 'look online' and buy a set of 4 valves with the pressure sensors built in and return to this chap...does this sound about right?

I have had a quick search on eBay but looks like I will very easily buy the wrong part, so may just wait until MB parts are open and order from them.

...

Depends what TPMS is fitted to the car DIRECT - it tells you the pressure in each tyre, valves are expensive or INDIRECT - it uses the ABS to tell you that you have a soft tyre ... go & look for it .... valves are the normal valve.

My 14 plate ML166 has the indirect system

 

[ThinkPad]

Perhaps it is direct as the dash has a reading of the pressure on each corner.

The tyre shop put water on the valve and noted bubbles. Hence their conclusion.

Will give MB a call tomorrow.

 

[mioba]

Yes if each corner is being measured then you have the posh version, a sensor on each valve - direct.
Good luck and keep us posted.

 

[EmilysDad]

Perhaps it is direct as the dash has a reading of the pressure on each corner.

The tyre shop put water on the valve and noted bubbles. Hence their conclusion.

Will give MB a call tomorrow.

It's the expensive version then ..... I'm sure that MB will help lighten your wallet some.

 

[ThinkPad]

I am sure they will. Looking online and I can see they are selling sets of four for around £100...MB will surely be more but at least I will know they are genuine and hopefully correct for the car...anticipating a painful phonecall tomorrow morning.

 

[ThinkPad]

Well looks like the valve and sensor are two separate parts so MB advised I can just buy the valves. Total cost after a very small discount is £120 for 4 valves. Ouch!

 

[mioba]

Maybe I miss something, why buy 4 valves if only one is out, or do they only come as 4.

 

[ThinkPad]

Tyre shop suspected two rear tyres both with same issue.

They suggested changing the front two at same time as a preventative measure. However, valid point. I could just change the rear two and wait to see if the front fail!!

 

[ThinkPad]

To update. TWO valves purchased and fitted. So far so good.

When they were fitting they also found two nails in two of the tyres ! Puncture repair performed. I have usually been against puncture repairs in the past, but nails get in these tyres so very often - the tread is hardly worn - will keep an eye on them in the near future.

 

[mioba]

Puncture repairs are as good as anything and a fraction of the cost. I have never had an issue with them and not sure as to your doubts.

I wouldnt be suprised if the original valves were ok and it was actually the puncture the source of the air leak.

Regardless all done and glad your motoring on