fluctuating temperature gauge

[paul73mt]

What do i got for first on driving to work this morning my tempature was just under the 80 mark on the tempature gauge where it normally sits at about 90 and dont move. The fan runs and have hot air from the blowers, so sticky thermostat or go for the tempature sender????

 

[paul73mt]

anybody??? Have pulled the wiring from the top of the thermostat housing and dosn't change the temp gauge and also found a sensor the goes directly into the engine block (on ther righthand side of the engine as you look in the engine bay) and that don't seem to make the gauge do anything either.

 

[intel500]

Hi don't know about the diesel thermostat just changed mine in a v6 c230 check engine light came on because the engine wasn't reaching a given temperature in a set amount of time when removed the thermostat showed signs of scoring on the thermostat where it must have been sticking mine also was reading 80 after new thermostat 90 so I would say the thermostat is sticking when the engine is cold check the temperature of the top hose if it gets warm as the engine warms up thermostat is leaking thanks

 

[paul73mt]

sorry to re erect this thread but its started it again (has always been ok in the summer months) but its started to do it again I can now sometime drive 10miles of so and the temp gauge is only just over 80 on the temperature gauge where before it aways went o 90 and stayed there. Sticking thermostat?????

 

[zipdip]

Well many thermostats fail open,and this would not have been a problem in the summer but now we are getting colder weather,you have noticed that the temp gauge is registering low,my only suggestion is to take the thermostat out ,you will see straight away if it is stuck open,if not put it in a pot of water and bring it to the boil on the stove and make certain it is opening,given your problem I suspect it will be stuck open,if it is buy another one,quiet a simple job to do

 

[paul73mt]

Only thing it the thermostat is part of the housing and to order the part will take 4 days which means I would be off the road for a week

 

[paul73mt]

ok well on the way home tried a few things started from cold and temp went up to about 85 @ a steady 60mph temp gauge reading just below 80 (with heating on) if I turn the heating off then temp will go up to around 85 but still not getting to my normal 90 . So think I should go for the thermostat ?? If I was to change this how much coolant would I expect to loose as just want to get enough to replace it.

Thanks

 

[paul73mt]

Well quick update I changed the thermostat only took 10mins and lost about half a cup of coolant now the car temperature gauge seems to seat at around the 90 ish mark and so far has stayed there so thanks guys