M42 thermostat

[slowklopdop]

Just tried to replace my thermostat due to it being the reason why I get bad fuel consumption in my e30 m42 engine.

For people who have replaced their thermostat, does it sit properly in the cooling side of the engine without the need to hold it in place?
Both my old and new thermostat do not sit snuggly and perfectly in place but rather plop out is this normal?

[jrobie79]

did you install the o-ring?

[bmwman91]

Yes it is normal to have it feel like it just loosely sits in the head. Make sure that it is facing the right way, with the arrow out and pointing up. Also make sure that the air bypass in the thermostat housing is clear...makes bleeding the system MUCH easier.

[Nick_S]

I felt like a fool last winter. I kept trying to install it with the o-ring facing the block which isn't right. It does sit loosely in the opening but snugs up once the housing is tightened onto the o-ring.