Engine Coolant Sensors

Re: Removal of sheared engine coolant sensors on a 1997 MGF VVC
(sharing my experience which may help others)


One of my jobs this week (on restoring my thirteen-years idle MGF),  was to replace the engine coolant sensors. 

The brown horizontal sensor leading to the ECU is of plastic construction and would not budge. 
I tried WD40, 19mm spanner, adjustable wrench, mole grips and heat, all without success and ended up totally destroying the plastic bolt head. 
I thought I was doomed,  but felt around the area and realised that the sensors are attached to an elbow,  which was attached to the cylinder head via two 8mm bolts  (hidden from view).
With a small extension bar and wrench,  I successfully removed the elbow. 

To get the now sheared off sensor out, I drilled a 5mm hole in the center of the sensor, hammered in a 6mm Allen key and got that joyous sound of a crack followed by positive movement. 

I therefore recommend that anyone trying to replace one of these stuck sensors,  just proceed straight to disconnecting the coolant pipes to the elbow and removing the elbow after unclipping the leads to both the sensors. This will  enable decent access to both the  sensors.


*Apologies if this has already been posted before and I am stating the 'bleeding obvious ' to many of you, or if any others have a more efficient method.