[ZSP.3R]

I just had my thermostat replaced this morning @ BMW Park Avenue Brossard. The Tech told me that the thermostat was left OPEN. My car only has 30k miles. Obviously its not normal.

What could cause this to happen at an early stage?

I don't drive hard. TRUST ME! (stored in winter also!) If I look on the bright side, I have a brand spanking new thermostat + coolant for free thanks to CPO warranty... But still...


Anyone else on the forum change their thermostat early?


.

[Chriztofor]

1) Your car is an 06 so age is the factor. Some people think (not talking about you) that if they bubble wrap their car and open it in 10 years it is still new. Just not true.

2) Consider yourself lucky, the thermostat and coolant are not covered here in the US.

3) Your thermostat failed because the coolant was old and "lifetime" therefore it was not getting proper lubrication (coolant not only "cools" but lubricates). Over time it loses its lubrication properties. At least they changed the coolant and your water pump will probably last longer.

[kanecvl]

New thermostat at 54xxx

[David1]

Originally Posted by Chriztofor

1) Your car is an 06 so age is the factor. Some people think (not talking about you) that if they bubble wrap their car and open it in 10 years it is still new. Just not true.

2) Consider yourself lucky, the thermostat and coolant are not covered here in the US.

3) Your thermostat failed because the coolant was old and "lifetime" therefore it was not getting proper lubrication (coolant not only "cools" but lubricates). Over time it loses its lubrication properties. At least they changed the coolant and your water pump will probably last longer.

Coolant quality has no bearing on the T-stat. On the pump yes. T-stats have been problematic for years on BMWs. My X3 needed a T-stat at 7000 miles. The electronic sensor built in to it fails or the stat itself. Nothing you can do to prevent failure.

[Tom K.]

Thermostat on my E46 was replaced under a recall at 32k and the replacement went south 50,000 miles later. At least they all seem to fail in the open position.

Tom

[NaTuReB0Y]

got my water pump and thermostat replaced..........a few months back

[Chriztofor]

Originally Posted by David1

Coolant quality has no bearing on the T-stat. On the pump yes. T-stats have been problematic for years on BMWs. My X3 needed a T-stat at 7000 miles. The electronic sensor built in to it fails or the stat itself. Nothing you can do to prevent failure.

The thermostat opens and closes constantly by an electrical connection AND by a spring inside the thermostat. Problematic thermostats are one issue, but poor coolant will also affect the thermostat. Besides cooling and corrosion protection, the coolant also lubricates. http://www.associatedcontent.com/art...ntifreeze.html

[Chriztofor]

Originally Posted by Tom K.

Thermostat on my E46 was replaced under a recall at 32k and the replacement went south 50,000 miles later. At least they all seem to fail in the open position.

Tom

Your lucky, the two I replaced on my e46 both failed in the closed position (car overheated). Note: I only replaced the thermostat 2x in 184,000 miles (not bad).

[David1]

Originally Posted by Chriztofor

The thermostat opens and closes constantly by an electrical connection AND by a spring inside the thermostat. Problematic thermostats are one issue, but poor coolant will also affect the thermostat. Besides cooling and corrosion protection, the coolant also lubricates. http://www.associatedcontent.com/art...ntifreeze.html

The article is incorrect. Thermostats do not need lubrication. The functional part of t-stat is sealed for it's short life in a BMW. Period. The BMW t-stat is junk. The only t-stats I replace now are the ones in BMW's for the past 10 years. Maybe one day they will use a quality T-stat.

[Chriztofor]

Originally Posted by David1

The article is incorrect. Thermostats do not need lubrication. The functional part of t-stat is sealed for it's short life in a BMW. Period. The BMW t-stat is junk. The only t-stats I replace now are the ones in BMW's for the past 10 years. Maybe one day they will use a quality T-stat.

Are you saying that no movable parts in a T-stat touch the coolant? If so, when mine breaks I will take a hacksaw to it to confirm.

[David1]

Originally Posted by Chriztofor

Are you saying that no movable parts in a T-stat touch the coolant? If so, when mine breaks I will take a hacksaw to it to confirm.

Correct. There is some movement, but not much. Just go the parts store and buy a cheap one and cut it open. But here is a basic one. Typically the spring fails/gets weak or the wax or something similar leaks out from a failed seal with new or old coolant. It will eventually crack or the cylinder splits open from fatigue. In 30 years I have never seen a rod full of gunk or corroded from the lack of coolant changes and I have done hundreds back in the day.

http://auto.howstuffworks.com/cooling-system8.htm

[Chriztofor]

^ Good to know. I was always under the impression that antifreeze lubricates the water pump AND T-stat. It looks like it just lubricates the water pump.

[David1]

One day, cars may not even need a stat with active aerodynamics that open and close vent doors in front of the radiator.