PS get the system pressure checked as one last step while you are at it- could be a failing HG as well....

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03 540I (GAK!!)
81 280E (W123)
70 LeMans Sport with pissed off Poncho 462"
1989 Silverado Step Side (under the knife- complete restomod)

By HG, do you mean head gasket?

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I am not who you think I am

Yep. That's another symptom of a blown HG. Gets hot, blows over returns to normal.

__________________
03 540I (GAK!!)
81 280E (W123)
70 LeMans Sport with pissed off Poncho 462"
1989 Silverado Step Side (under the knife- complete restomod)