Thermostat

Revision as of 21:32, 12 January 2008; view current revision
<-Older revision | Newer revision->

Datsun 1200 uses a traditional pellet-type engine cooling thermostat. It regulates temperature by closing when cold to keep hot water in the engine, and opening when hot allowing the coolant to flow to the Radiator to shed heat.

Replacement

Replacement of the thermostat is called for when:

• the engine runs too hot and other causes have been out. See Cooling System Diagnoses
• the engine runs too cold

1. Put a bucket under the radiator fan to catch spilled coolant
2. Loosen the clamp on the hose at the water outlet
3. Twist and pull the hose off the outlet
4. Remove the two fastening bolts
5. Scrape all traces of gasket off water outlet and cylinder head face
   • be careful not to nick the aluminum of the gasket faces
6. Fit thermostat into engine, then gasket, then housing and tighten moderately
7. Top up coolant
8. Rinse spilled coolant off engine and body with water
9. After engine has been fully warmed up, and cooled down, top up coolant again.

Be sure to fit thermostat with spring facing into engine

WARNING: Due to air pockets, the coolant level usually drops down and the engine can easily overheat if not monitored for a few days after changing the thermostat.

Temperature

It is not unusual with any 10-year old stock radiator for the temperature to rise during summer. If you have this, don't panic. The engine can run all day close to the "H" mark. Just don't let it go over that. If you are worried, replace the radiator.

Use the stocko fan. Electric fans are notorious for failing to cool the radiator in stop/go traffic.

What is the correct temperature the engine should run at? Primarily, this depends on the thermostat. You can get different temp thermostats, and the coolant should stay steady at that temperature:

• 160 degree
• 180 degree
• 212 degree

160-degree is good for drag racing, or for use with low octane fuel. 180 is recommended for all street cars, it will keep the oil at optimum temperature (oil runs about 20 degrees hotter than the coolant). 212 degree is only run on emission-control cars along with a 14 lb. radiator cap to prevent boiling.

After the thermostat, the radiator is the next factor. If your temp. stays steady except on the hottest summer days it seems you need a replacement radiator, either a new or rebuilt stock unit, or a larger used unit (from a B210 or B310).

Types

Newer Type - advanced type with 'jiggle' valve

Thermostat Testing

Test it like this:

Thermostat Housing

Nissan calls the thermostat housing the "Water Outlet".
Buy at http://www.rockauto.com

• 11062-18000 GASKET-WATER OUTLET
• 11060-G0300 OUTLET-WATER B110 A12 JDM
• 11060-G0300 OUTLET-WATER B110 A12 AUTOMATIC USA
• 11060-G0300 OUTLET-WATER B110 A12 MANUAL from 0273 USA
• 11060-H7000 OUTLET-WATER B110 A12 MANUAL from 0373 USA
  • Has boss for temp switch

    22120-U2001 ASSY-SWITCH WATER TEMP from 0373

There are a number of different type for A-series engines:

• 2-bolt Type -- as used by early engines, and some late engines
• 4-bolt Type -- newer engines

It further breaks down:

• 2-bolt Type -- as used by Datsun 1200
  • B10/B110 Type, outlet points 180 degrees
  • Late B110 USA -- with boss for thermo switch
  • B210/B310 Type - Outlet points 225 degrees
• 4-bolt Type -- as used by some newer engines
  • with accessory mounting bosses
  • with accessory mounting bosses and Air fitting
  • with accessory mounting bosses (forward) and Air fitting

2-bolt Type Thermostat housings attaches radiator hose at:

• B10/B110: 9:00 o'clock (180 degrees)

  

• B210/B310: 10:30 o'clock (225 degrees)

  

Head Mating Surface - A14

Photo Index

A14/A15 high angle

B210 Late, 3-outlet housing

Air Pump style

Late, Accessory bracket type

Part Numbers

http://www.rockauto.com

Cooling Thermostat. $7-$16

---

Honda 1994 - 1996 PASSPORT

---

ISUZU 1989 - 1994 AMIGO, 1992 IMPULSE, 1981 I-MARK, 1981 - 1995 PICKUP, 1985 - 1989 I-MARK, 1991 - 1997 RODEO, 1988 - 1990 IMPULSE, 1984 - 1991 TROOPER

---

NISSAN , 1971 - 1973 1200 , 1980 - 1986 720 PICKUP , 1977 - 1988 200SX , 1977 - 1981 810 , 1979 - 1982 210 , 1974 - 1978 B210 , 1974 260Z , 1986 - 1989 D21 PICKUP , 1975 - 1978 280Z , 1976 - 1978 F10 , 1979 - 1982 280ZX , 1982 - 1984 MAXIMA , 1979 - 1982 310 , 1987 PATHFINDER , 1971 - 1973 510 , 1983 PULSAR , 1978 - 1981 510 , 1983 - 1989 PULSAR NX , 1971 - 1972 521 PICKUP , 1982 - 1988 SENTRA , 1973 - 1976 610 , 1982 - 1989 STANZA , 1972 - 1979 620 PICKUP , 1987 - 1988 VAN , 1974 - 1977 710

---

Photo Index