[AllBlackBimmer]

So I took my car into the dealer for a battery... they quoted me $300... it is now $375 O well whatever, guess thats what I get...

But, the good part about me taking it to the dealer, I asked them to scan my car for error codes (my car is CPO'ed for another 3 months) and they found a fault in the thermostat.

Now, I know everyone always replaces the thermo when they do the water pump, but my dealer is claiming the water pump is fine - OK, that is fine but with the thermo acting up, does that mean damage to my water pump?

Is this a sign of things to come? Does this already tell me I am going to have to replace the water pump? (I was planning on it already actually)

If they are replacing my thermostat, is there ANYTHING else i need to ask them or request them to look at or fix?

It is a little past 1pm - east coast time (usa), and I am going to pick my car up at 4pm... so I have very little time to call them back...

thanks!

[Meeni]

How many miles ? The pump itself is outrageously expensive. If you are under 60k I would keep it. Over that, tough call. Over 90k just change it, its gonna break soon.

You can always take the car back for today, and return next week to complete the job. Don't wait too much tough, the thermostat is supposed to fail open, but that doesn't always work.

[AllBlackBimmer]

Originally Posted by Meeni

How many miles ? The pump itself is outrageously expensive. If you are under 60k I would keep it. Over that, tough call. Over 90k just change it, its gonna break soon.

@ 65k.

I don't really have a "choice" if they replace it or not, i am more or less looking for a way to get them to replace it, under CPO...

..or atleast ask the "right questions" to get them to highly consider it, or able to find some type of fault with it...

[Meeni]

Ha, CPO. Doubt they'll change it if the pump itself has not thrown error codes, it costs a little fortune. Ask if there is any chance that the thermostat has made the pump run dry (that would have damaged it). Very improbable though.

[GoRomeo]

Ive heard that our thermostats when they go bad, they stay "stucked open" for the same safety that concers the engine from overheating. Not sure but Ive read it somewhere here. I recently had my SES light on about a bad thermosthat. I dont have any overheating issues or anything. Did not replace yet, I will wait till my water pump goes bad to change both. I got rid of SES light with BT tool TORQUE app. Till today no issues.

[AllBlackBimmer]

Originally Posted by GoRomeo

Ive heard that our thermostats when they go bad, they stay "stucked open" for the same safety that concers the engine from overheating. Not sure but Ive read it somewhere here. I recently had my SES light on about a bad thermosthat. I dont have any overheating issues or anything. Did not replace yet, I will wait till my water pump goes bad to change both. I got rid of SES light with BT tool TORQUE app. Till today no issues.

The only signs I sort of knew something wrong was this:

Under minimal load, or short driving, my fan would kick on at HIGH speed, I'm talking my car sounded like a damn 18-wheeler with the fan running FULL blast like that, I suspect a new thermo will fix that.

I already asked them to check into this the LAST time my car was at the dealer - everything was "fine" then, but now it is bad? Weird. No over heating issues at all, car drove fine, other than the radiator fan running like crazy.

It was odd, it didn't always do that. I could drive aggressively or long and the fan would be fine, then randomly would kick on like crazy. Outside temp really wasnt a factor either as it did it on 90 degree days, as well as a cool 60 degree fall day.

[GoRomeo]

I see. If you had an error code saying that you had a bad thermostat then this should fix issue. You should ask them to check temp sensors etc... I am sure they know but just to be sure. Your symptoms can be cuased by a lots of things not only thermostat.

[Blackhawk36]

I would let them replace the thermostat. Fan on full blast is usually a bad water pump. Once they take it apart they will probably call you and say, "oh, the water pump is bad too!" and you get it CPO'd.

If you tell them to do the pump before that, you will pay.

[kfrazie1]

I had my thermostate replaced under 3rd pary warranty. Water pump was fine so i left it in. Im at 75k miles. Thermostat also fails safe (open), which basically just means motor will take longer to heat up.

[Efthreeoh]

So it's probably too late to give this advice since you got ripped off by the dealer by now, but for anyone else in this situation, here is how the t-stat and water pump fail.

The t-stat mechanically fails open, as per the cooling system information in the Bentley service manual. If the t-stat fails and throws a code it will illuminate the SES light because the t-stat is considered part of the emissions system since it regulates cold-start exhaust emissions via regulation of engine temperature. Ask the dealer what code (by number) it threw and then google the code and see what the code is for. If the SES light was not on, I doubt the t-stat is bad. The heating element in the t-stat goes bad and throws the code. If the dealer actually did replace the t-stat then it will be brown plastic instead of aluminum (but I'm not sure if by 2008 they changed the t-stat to plastic bodied from the factory). I let my t-stat go (throwing the SES every once in a while) for almost 10,000 miles before I replaced it; it will not overheat the engine.

As far as the water pump is concerned, it throws a shadow code that is not detected unless the car is scanned. Research water pump in the maintenance section and you'll find out all the info you need about when and how it fails. There is no predictability as to when the pumps fail. I would not replace a pump just because the t-stat is bad. The t-stat comes off first because it is bolted to the pump. It makes sense to replace the t-stat if the pump fails because the t-stat is relatively inexpensive ($100) as compared to the pump and adds no labor to the cost of a water pump replacement and has to come off to get the pump out.

[luv135i]

How did he get ripped off if they replaced the t-stat under CPO?

[AllBlackBimmer]

Update.

Replaced t stat under cpo, asked about the pump and they said it was fine with no codes I did not get an ses light ever, so I never really know anything was wrong other than the fan running full blast sometimes after short driving which I knew wasn't right.

[osteopathXI]

Originally Posted by AllBlackBimmer

Update.

Replaced t stat under cpo, asked about the pump and they said it was fine with no codes I did not get an ses light ever, so I never really know anything was wrong other than the fan running full blast sometimes after short driving which I knew wasn't right.

I would have paid for the water pump $(475 at Tischer) and had them replace it when they replaced your t stat. Then you wouldn't have had to pay any labor when the wp finally does go since its the same labor to replace t stat as wp.

[GoRomeo]

Originally Posted by Efthreeoh

So it's probably too late to give this advice since you got ripped off by the dealer by now, but for anyone else in this situation, here is how the t-stat and water pump fail.

The t-stat mechanically fails open, as per the cooling system information in the Bentley service manual. If the t-stat fails and throws a code it will illuminate the SES light because the t-stat is considered part of the emissions system since it regulates cold-start exhaust emissions via regulation of engine temperature. Ask the dealer what code (by number) it threw and then google the code and see what the code is for. If the SES light was not on, I doubt the t-stat is bad. The heating element in the t-stat goes bad and throws the code. If the dealer actually did replace the t-stat then it will be brown plastic instead of aluminum (but I'm not sure if by 2008 they changed the t-stat to plastic bodied from the factory). I let my t-stat go (throwing the SES every once in a while) for almost 10,000 miles before I replaced it; it will not overheat the engine.

As far as the water pump is concerned, it throws a shadow code that is not detected unless the car is scanned. Research water pump in the maintenance section and you'll find out all the info you need about when and how it fails. There is no predictability as to when the pumps fail. I would not replace a pump just because the t-stat is bad. The t-stat comes off first because it is bolted to the pump. It makes sense to replace the t-stat if the pump fails because the t-stat is relatively inexpensive ($100) as compared to the pump and adds no labor to the cost of a water pump replacement and has to come off to get the pump out.

Absolutely correct. Thanks for sharing!

[AllBlackBimmer]

Originally Posted by osteopathXI

I would have paid for the water pump $(475 at Tischer) and had them replace it when they replaced your t stat. Then you wouldn't have had to pay any labor when the wp finally does go since its the same labor to replace t stat as wp.

Yea, wish i could've did that, but I needed my car back and couldn't wait to order/ship a WP from Tischer... I realize I could've just told them to wait to install the Thermo, but like i said, I needed my car.


Did they flush and refill my coolant when they replaced the thermo? or is that only when they replace the WP?

[osteopathXI]

Originally Posted by AllBlackBimmer

Yea, wish i could've did that, but I needed my car back and couldn't wait to order/ship a WP from Tischer... I realize I could've just told them to wait to install the Thermo, but like i said, I needed my car.


Did they flush and refill my coolant when they replaced the thermo? or is that only when they replace the WP?

Loaner FTW

[Tom K.]

Originally Posted by AllBlackBimmer

Did they flush and refill my coolant when they replaced the thermo? or is that only when they replace the WP?

When the thermostat went on my E46, the coolant also had to be replaced. But as the symptom of a bad thermostat is an engine that takes forever to warm up, I don't understand why your cooling fan was running so much. In my case, the car was fine in the summer, but ran cold with concomitant poor fuel ecomony (and little cabin heat) when the weather turned cold.

Tom

[AllBlackBimmer]

Originally Posted by Tom K.

When the thermostat went on my E46, the coolant also had to be replaced. But as the symptom of a bad thermostat is an engine that takes forever to warm up, I don't understand why your cooling fan was running so much. In my case, the car was fine in the summer, but ran cold with concomitant poor fuel ecomony (and little cabin heat) when the weather turned cold.

Tom

Because it fails open? no idea? But car warmer up just fine. I didn't always have the fan run like that, did come and go, but did notice it a lot

[Efthreeoh]

Originally Posted by osteopathXI

I would have paid for the water pump $(475 at Tischer) and had them replace it when they replaced your t stat. Then you wouldn't have had to pay any labor when the wp finally does go since its the same labor to replace t stat as wp.

This is completely wrong. Replacing the waterpump would have added additional labor cost to the repair. The t-stat is bolted to the waterpump. The water pump does not need to be removed from the engine to remove the t-stat. The t-stat comes off first during a WP replacement so there is no extra labor to replace the T-stat when doing the waterpump, but there is extra labor cost to replace the waterpump when in there just to replace the t-stat.

They most likely replaced the coolant as part of the repair. The t-stat is at the bottom of the cooling system, so the cooling system needs to be completely drained to replace the t-stat. If the coolant was fresh, the dealer could have saved it and reused it, but based on the milage, they most likely used new coolant. Check the parts bill of material on the repair order to see for sure. If they replaced the coolant there will be a P/N for 1 gallon of BMW antifreeze.

Additionally, one dealer would not buy a waterpump from another on-line BMW parts retailer such as Tischer; they would have charged the OP the full BMW MSRP for the pump and added it to the bill. Also they would not warranty the work if they used customer-supplied parts (even if it was a OE BMW part in an unopened BMW parts box).