QuestionI have Plymouth Voyager 95, 3liter, V6 engine. I have to change the termostat, because I think it doesn't work. Where is this part exactly? If I need some special tools to fix this, please let me know. Thank you in advance.
Regards
AnswerHi Michael,
Out of curiosity what is it about the temperature control of the engine that makes you think the thermostat needs changing?
If it does here is how to locate it and do the job. Follow the upper large hose from the radiator to the top side of the engine. The round hemispherical fitting held in place with two bolts whose outlet receives that large hose is the thermostat housing cover. If the hose itself looks puffy or cracked at either end this would be a good time to replace it at the same time as the thermostat, and also make sure you get a new gasket for the interface between the housing cover and water box into which the thermostat is seated.
Begin by opening the radiator drain and draining off into a collecting pan about a gallon of coolant so that its level in the engine drops to the point where it won't run out all over the engine when you subsequently remove the two bolts and lift off the thermostat housing cover. You can reuse the coolant if you collect it cleanly and it is in good condition.
Remove the two bolts and lift off the housing cover. You may find it easier to first remove the large clamp that holds the radiator hose to the outlet particularly, and then the hose, if you plan to replace it. Once the cover is removed you will see the top of the thermostat sitting in the "well" of the water box. Note that there is a small hole in the flange of the thermostat that faces the front of the engine and that the coil end of the thermostat is down in the water box. You will want to insert the new thermostat in exactly the same configuration as you found the old thermostat, and be sure that the round flat flange of the thermostat is seated in the countersunk depression of the mating surface of the water box. Failure to position the thermostat exactly as you found it may give you problems so look carefully. Submerged in the water box there is a metal casting wall and the "bridge" on the underside of the thermostat must be ligned up so as to not make contact between the wall and the bridge (do that by aligning the small air vent hole just as you found it originally when you opened the housing). Clean off the mating surfaces of the box and the housing cover and put a new gasket on the box so that its holes line up with the bolt holes (wet the gasket with water or coolant). Then place the cover back over the thermostat and fasten the bolts down to 9 foot-pounds of torque (modestly tight but not enough to strip the threads of the water box bolt holes). Reattach the upper radiator hose if it was removed and tighten its clamp. Then refill the radiator with the drained fluid, and finally add the remaining coolant to the overflow bottle. Start the engine and check for leaks and observe the temperature rise as the engine warms if the van has a temp gauge. It should rise to no more than 3/4 scale.
Check the seal between the housing cover and the box for leaks, as well as for leaks around the large hose clamp. Tighten if necessary.
That is the procedure. You really don't need any special tools, just a wrench or socket and socket handle that fits the bolt heads. If you can borrow a torque wrench to get the bolts to 9 foot-pounds of torque, that would be desireable but not necessary.
Roland
