850 thermostat fail. OEM.

[cn90]

Ben,
- I have an E39 1998 BMW 528i 5sp man trans with 150K, engine quiet, beautiful machine. Stay away from E60 series.

Erikv11,
- When the tstat prong breaks, the tstat opens sooner because the spring tension is no longer there ---> engine runs cold.
- Just google "tstat broken prong" or "tstat broken tabs", you will see these images all over the web.

[erikv11]

...
- When the tstat prong breaks, the tstat opens sooner because the spring tension is no longer there ---> engine runs cold.
...

OK this is what I was looking for, thanks, makes perfect sense.

Ben850, that stat will probably open early if you drop it in hot water, it is likely *not* stuck closed, and it probably failed who knows when before you pulled it from the car etc, all the pieces of this thread fit together now.

[abscate]

I hope you noticed they shipped it you already "STUCK" (although technically, its "schtook"

(a bit of Teutonic Titillation)

[Ben850]

I do also understand another Germanic Yiddish dialect, which may tell you "das ist shtookt" It is a vernacular that spell check is attacking as I type. I love the way it rolls off the tongue, and remember the relevance of its resounding through the mountains of Skokie Illinois in my childhood years.
Memories...
Edit: Grandmothers kitchen in Chicago.

So Stay away from the E60 Series. Got it. Danke.

[mecheng]

Which E60? My friend only had small problems, and they still have non turbo engines

[dosbricks]

.....the relevance of its resounding through the mountains of Skokie Illinois in my childhood years.
Memories...

Mountains of Skokie???--that would be like a highway overpass?

I have a Volvo blue label temp sensor waiting until I get time to do the thermostat, heater core and hoses on the S70 (next up). Pricy little gizmos. I certainly chafed at paying $50.83, but after reading the info in this thread, I feel better that I ordered the OE part--same as a few years ago on the wagon.

[northernlights]

- When the tstat prong breaks, the tstat opens sooner because the spring tension is no longer there ---> engine runs cold.

The Wahlers that I have seen fail have broken at the top strap, and as a result failed open. To me it looks like they were designed to fail open, because having a thermostat fail closed is very bad.

[Ben850]

Mountains of Skokie???--that would be like a highway overpass?
So you must know the I-94 exit at Old Orchard Blvd.
That was my mountain.
Now that I think of it, There was a way to run our sleds down that embankment in the winter.
Mine was a "Rosebud".
I could not make this stuff up. Photos later in another thread.