1996 Omega 2.5 V6 Temp Gauge Goes Up When Heater Turned On

[Daraven666]

HELLO
I am a newbie on here s here goes
I have a 1996 p plate omega with a 2.5 v6 lump in it
When it is warmed up i turn the heater on and the temperate gauge rises a bit , i am suspecting it will either be the sender unit on the engine or the gauge itself at fault
Is it noraml that when you start up the car when warm the temp gauge goes right up then comes back down again
Anybody had similar problems
Sorry for the list but its doing my brains in
Dave

[TheBoy]

Locking, as cross posted.

Other post http://www.omegaowners.com/forum/index.php?topic=94706.msg1185849