temperature gauge has been wandering only slightly between approx 80 and the 90 degree mark where as it used to sit at 90 all the time, searched on here and this symptom seemed to be the result of a fault temp sensor so i changed it for a new one but its not fixed it, car runs as sweet as ever but any ideas what else the problem could be?

cheers

temperature gauge has been wandering only slightly between approx 80 and the 90 degree mark where as it used to sit at 90 all the time, searched on here and this symptom seemed to be the result of a fault temp sensor so i changed it for a new one but its not fixed it, car runs as sweet as ever but any ideas what else the problem could be?

cheers

Could it be early indications of the water pump packing up? Seems common on the Octy if you have the OEM plastic impeller type one fitted (mine went not to long ago :(). The temp did start to get higher than normal just before it went. If it seems OK when driving very slow, or on idle, but rises when you boot it, then I would say Water Pump.

If you are really lucky though, it might just be the thermostat

no its neve rover heating, never ever rises above 90 but cheers handy to know and worth keeping an eye on.

thermostat aswell worth looking at, ta

mine sits just above the 90 mark, has done since i got the car, ive been told its probely just the temp guage abit out, so unless it geos over anymore not to worry about it,

Have you had the coolant changed?

Does it rise to normal temp when thrashed?

It could just be the thermostat.

Are the fans cutting in unnecessarily?

It seems to be very random when it fuctuates, never goes above 90 or below 80 just intermittently wanders between the 2.

How about the temp sensor ?

Mine done this aswell, so to be on the safe side, i just replaced the sensor and the thermostat at the same time (my pump has been changed already so i ruled that out)

For the little cost, it may be worthwhile just doing them both.

My E38 7 series used to do the same thing.

On my way to work it will go from a solid 90 down to 50, ping pong for a bit up and down, then back up to about 80 and sit there.

Its not an accurate temp reading as the needle moves too quickly, so ive concluded mine is an electrical thing, and probably the sensor / sender part of it.

In traffic it will usually sit slap bang on 90 though.

temp sensor has been changed and now im considering changing the thermostat but where the hell is it and is it easy to D.I.Y?

Would a too high antifreeze concentrate give a lower reading? due to not being able to hit the 90 Degree mark?

Have you had the water pump replaced recently or coolant changed?

water pump hasnt been changed and the coolant hasnt been touched either.car still runs fine tho

Irrespective of coolant concentration, the thermostat should open and close at its design temperatures. If its "overcooling", the stat should be closed more than normal I'd have thought.

My best bet is that there's some crud built up in the coolant - catches on the temp sender as it circulates, insulates it for a few minutes, then gets pumped away. Suggest change of coolant.