I was in traffic near a mall (pretty much stop and go for 20 minutes) and my water temperature read 233 (scangauge). By the time i realized it, the engine shook and there was a vibrating sound... and the temperature dropped back to 220.

The last time this happened was when I was stuck in the snow (yesterday) and in frustration i reved it in 1st gear to about 5500 rpm. Same thing happened... water temp just went up, engine shook/made some sounds/followed by temperature decrease...

Is something wrong with my car? oil related? possible coolant levels?

 

The highest I've seen is 225 for brief moments when climbing a grade fast. I'd ask your dealer about it, especially with the shaking and vibrating. Did you ever have the cold start rattle?

 

i do but i usually start up the car... go do something and come back 10 min later....

if it doesnt chatter... i let it get to 100 before i actually start moving...

I thought cuz i wasnt moving... the radiator isnt properly getting cooled down and is sitting around in ambient air... isnt their a fail safe for high water temps that brings the overal temp down for these things?

 

I don't know the details of the MINI's cooling system. I believe it is different than the old systems in 20th Century cars.

You need to get that cold start rattle fixed. It is causing damage to your timing chain and can eventually destroy the engine.

 

Not sure if the mini has a similar cooling system as a BMW. My 3 series had a low speed fan that came on at a lower temp, maybe 190 and high speed kicked in at a higher temp. If your low speed switch or relay is not working the coolant temp will cycle up and down like that. The shaking is likely the inrush current needed by the electric fan going from 0 to high instead of going from low to high.

Just a guess. To test, you can force the high speed fan to stay on by using the A/C (no problem here in So.CAL but maybe not for places affected by the cold rattle) Definitely fix the cold rattle / timing chain ASAP.