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TSpark Thermostat Replacement

TSpark Thermostat Replacement
The 156 16v Twin Spark thermostat is mounted at the opposite end to the cambelts ... i.e. the rear of the block, and underneath the intake pipes. Before replacing, my temperature gauge struggled to even get to 70C especially on a motorway run. In traffic it would climb to 90+ and the cooling fan would cut in as normal. But for me this indicated a thermostat stuck in the open position. Long term this would affect my fuel consumption. Now from cold I can watch the temperature slowly climb up to around 90C, when the thermostat opens and the temperature then drops again as all the cool water in the rad starts to circulate. It will momentarily drop down to just above 70 and then stabilise to around the 75-80 mark, depending on traffic/driving conditions.
A new 16v Thermostat unit--->

A new 16v thermostat is supplied as an assembled part including a new body. There is a ring seal build into the body, but you will need to remove and replace the temperature sender unit. It took me about an hour - mainly due to the fact I didn't have a Repair CD then. What also slowed me down was having to remove the battery half way through. You'll probably need a longer length socket or a shortish extension. It was getting access to the bolt underneath that caused me most problems. Cover the top of the gearbox housing to avoid fluid entering the clutch housing via an inspection hole) 1. 2. 3. 4. 5. 6. 7. 8. 9. Optional: Remove battery and/or intake pipes for more clearance Remove the top hose and drain off excess coolant Remove two small heater hoses (two extra fittings on unit!) Disconnect and remove the sender Undo the two bolts to remove unit (bit more fluid loss) Clean up the face of the cylinder head Bolt new thermostat unit back on: torque to 1.7-2.1 daNm, 17-21Nm, 12-15 ft/lb Reconnect the three hoses (new jubilee clips) Replace sender and reconnect to wiring

10. Refill with coolant mix and start!! Check for leaks and watch temp gauge. The larger jubilee clips are 25-40mm, smaller are 16-27mm. Both were reasonable tight fits as I didn't want a long end left over when tightened. I bought mine from Halfords in boxes of 10s as this worked out cheaper as I had other jobs to do. The part numbers were HC11 and HC13. And I paid just over 35 for a new thermostat from my dealer, plus Paraflu coolant mix, and a 5l bottle of distilled water from Halfords. Mix Paraflu and distilled water in 50/50 quantities.
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