Motor heat-up issue on going with gsum 1991 BMW 525i

poss headgasket issue. have a chemical block test done to ck for hydracarbons in cooling system

Just saw this post after replying on the earlier one. You say it goes from cold to red in about 2 miles.... I'll repeat what I stated in the other post.at cold start with closed system, does the rad hose go from litlle pressure to lots of pressure within a half-a-minute or so? Also something easy to check- - do you have one of those funnel adapters for the radiator fill? If so , do bubbles come out while running and what does it do when you rev the engine? 50s& 60s cars huh? Think old school , those diagnostic techniques are what tought and designed the 'new school'. Also one other thing --- again , don't want to sound insulting ,cause it sounds like you've got more patience than me , but...........any chance the t-stat could be defective or is it possible on that set-up , for it to go in in the wrong direction? God I hope some else has some better answers!!!....One other random thought Radiator sludged causing restriction? compare heat issue inside to what you already said --could be air in the system causing low heat output. Does the heat improve if you rev it up then cool down when you let off the throttle?