DIY BMW E39 M5 Thermostat

I used a Stant 180F (82C) thermostat. Part # 14538
You need 2 different o-rings.
11531407002 x 2
11531406249 x 4
Good luck! It's a lot of tugging, wiggling and pulling.
Crush washer that I lost is part # 07119963072 x 2
Use some RTV Silicone for the Stant thermostat! The seals are slightly smaller and coolant will leak out when the system is pressurized. Very little RTV is needed, just around the rubber seal and some around the mating faces of the housings.

[@ivancontreras751]

Good explanation point... i lost the brass washer too

[@cparente7]

Thanks for video. You did not change the metal washer inside the housing - any issues due to that?

[@MINIzguy]

Good luck with getting an S85 to fit in our engine bays. Have you seen how cramped it is to work it with 2 less cylinders? It will also be a wiring nightmare if you are able to shoehorn an S85 in their too. If you do decide to go for it, good luck!

[@MINIzguy]

Brute force. My car ran cold, especially during the winter. Now the heat is strong and warmup times are short. I have a bad CPS now so it is still running rich

[@MINIzguy]

I've never swapped a motor and don't know what it will take to get an S85 working. If you think it will fit, I'm sure some shop will be able to get the wiring done.

[@thrty8street]

How do you bleed it?

[@MINIzguy]

Start the car and bring revs up to 2k with the heater core open