thermostat temp

Morning,
so it turns out I think my stat has packed up. Cool air blowing in the heaters and temp gauge not moving.
a parts supplier lists two different ones. Is an 88' the right one? I assume the plastic housing needs replacement at the same time?!
Cheers

aye 87/88 is correct. if you're lucky you have an alloy flange if so just need the seal, if plastic get a new flange too

Ok random question.  When I got stuck in traffic today the temp rose to half way. The trouble is most of my commute is motor way and the needle barely lifts, the air is warm but not exactly hot.  Do you think it's a sticky stat or does motor way driving just keep the engine that Cool? Cheers

sounds like your thermostat is missing or stuck open for sure, the temp should rise to 1/2 and stay there no matter what. it may rise to near 3/4 in traffic then fan should cut in and bring it back, but it should never drop below 1/2 once it gets there.

your gauge may sit slighty under or over from 1/2 depending as some gauge/sensor combos can be slightly off etc but basically once you get to the normal running temp of your car it shouldnt drop below that again

What is your oil temp reading, the oil is cooled by the water as well?
My thermostat got stuck open last winter and on the move (A roads at 50 mph ish) the oil would not heat above 80 degrees but it was freezing in the mornings but as soon as I stopped in traffic the oil temputure would go up.
Fitted a new thermostat, o ring and new coolant and been fine since.

Hi all, 
more help required!! I have changed the stat, but the red light on the water temp keeps flashing. I changed the sender on the header rain but the light still flashes!! Any ideas welcome!!

unplug and bridge the pins on the level sender if it still flashes pull the relay out of the socket above the fusebox #42 or 43. if that stops it the relay or tank wirign is the problem, if not the coolant temp sensor, dash or wirign is at fault

Sorted cheers!