i went got my monte from where i was workin on it and the tranny on it doesnt seem to stay engauged or down shifts quite offen. It will go fron 1st to 2nd just fine but when it hit 3rd it will booge down and at 35mph there abouts it will like kick back down to 2nd and jump back to 3rd again. Any ideas??

Also, why im at it, the cars temp gauge goes from 220 then up to around 280 and like bounce between the 2 temps and it wouldnt go below 220. its done it before at start up after 5 minutes or so of warm up but after a few minutes it would drop back done to around 180 or so. IT doesnt start steaming nor do i hear the coolant boiling at all. Im thinkin themastat maybe? Any ideas on that??

Heres what i found out today:
I went out topped off all the fluids and started her up. Let the temp get to 220 there abouts and shut her down, poped the hood and on the hose thats on the top of the rad. to the themastat is cold and also is the ones to and from the heatcore. The only one that has heat to it is the one from the bottom of the rad to the water pump.

Im i correct in guessin that its a bad thermastat???

Also ive notice some smoke coming from the drivers side rear of the motor when i shut it down not sure where its comning from tho.

heating problem is most likely the thermostat, the trans may need a throttle valve cable adjustment, what trans do you have?

you need to check out your temp. after 5 min. at idle your temp. would not be 220 with a stuck thermostat. at 280 you would need much more then a thermostat, head gskts. heads, ext. your temp. gauge doesn't work at high end. if the temp. is higher then 180 and only 1 rad. hose is hot replace the thermostat. better verify temp. first since we know the gauge needs help. can't help with trans.....