Normal running temperature

Listed below are temperature ranges from by SELOC members from their stack display within the car.

Model	Engine	Modifications from Standard	Motorway (70mph) type crusing range (deg C)
S3 S (220)	1.8 Toyota 2ZR	Standard	92-93
S2	1.8 Rover 'K'	Standard	96-97
S2	1.8 Rover 'K'	Eliseparts remote T-stat	82-84
S2	2.0 Honda K20	Eliseparts Hi-Pressure Alu rad	84-86
S2	1.8 Toyota 190	Standard	83-86
S2 111S	1.8 Rover 'K'		89-91
S2 111S	1.8 Rover 'K'	Eliseparts Hi-Pressure Alu rad	85-86
S2 111S	1.8 Rover 'K'	PRT with PEL500150	84-85
S1	1.8 Rover 'K'	Rover PRT 82° stat	80-81
S1	1.8 Rover 'K'		87-89
1999 S1	1.8 Rover 'K'		86

Fan

The service manual states the fans at the front should automatically switch on when the coolant temperature rises 101/102°C. The temperature should then fall and the fan switches off when the temperature drops below 98/96°C.

Temperature senders

The S1 has two Temperature senders: brown (sends to ECU), blue (sends to dash). The blue temperature sender is notoriously unreliable and often fails, resulting in temperature readings approx 10°C lower than reality. The blue sender is also a "single wire" type which is affected by electrical load. In most cases, a 1°C rise in temperature can be seen when turning on each item of electrical equipment, e.g. headlights, heater fan, windscreen wipers.

The S2 (Rover engine) has a single (black) temperature sender for both ECU and dash. There is a legacy blue housing, part #A111E6047S as in the S1, but it does nothing.

The S2 and S3 (Toyota engine) has a single black temperature sender, although different part numbers in the 1Z and 2Z engines.