ACtion Magazine - May 2013 - (Page 34)

Nissan Double Thermostat Design 2002-2012 Nissan Altima 2.5L 2011-2013 Nissan Juke 1.6L H ave you ever replaced a thermostat on one of these vehicles and found the cooling system still overheats? If so, you probably found out the reason after spending way too much time searching, tossing a few tools and uttering some profanities. For those who have yet to experience this confusing problem, let’s look at the possible culprit. As odd as it may sound, some models of Nissan cars utilize a double thermostat design. The 2002-2012 Altima 2.5L (QR25DE) engines and 2011-2013 Juke 1.6L (MR16DDT) engines incorporate a secondary thermostat, referred to as a “water control valve” to shorten engine warm-up times. This second valve helps improve both engine emissions and fuel economy. Essentially, the two are the same type of device and look similar. Engine cooling system diagram for 2000-2012 Altima with 2.5L engine. The water control valve holds the coolant in the engine block until it reaches an optimum temperature, then opens to allow the coolant to join the circulating system. Valve Locations The water control valve is located at the rear of the engine, at the water outlet to the radiator, whereas the thermostat is located at the water inlet. Note that these water control valves will have different part numbers than the normal thermostats found on these engines and will open at different temperatures. Typically, the thermostat will open at 177-182°F (80.5-83.5°C) and close at Engine cooling system diagram for 2011-2013 Juke with 1.6L engine (model equipped with CVT shown). 171°F (77°C). The water control valve will open at 200-206°F (93.5-96.5°C) and close at 194°F (90°C). Testing and inspection can be performed by using the common immersion and heating method to observe opening temperature. If you have any doubt, it’s always best to replace either valve. Be sure to access the correct service information for the year, model and engine for the vehicle you are servicing. ❆ 34 ACTION • May 2013 Reader Reply

Table of Contents for the Digital Edition of ACtion Magazine - May 2013

Action Magazine - May 2013
Freeze Frame
Virtual View
Under the Southern Cross
Leonard's Law
News & Updates
What Is Happening in the Auto A/C Industry?
New Equipment, Tools and Service Parts for 2013
Striking Customer Service Gold
Asociation News
Quick Check
New Products & Services
Last Watch

ACtion Magazine - May 2013