The heater works when the thermostat is in, but not out(probably due to the fact that the engine runs without the thermostat but it runs REALLY cold like below 100 degrees) and I don’t think that the coolant is making it all the way around the engine because the hose behind the thermostat is always cold when it should be searing hot. The engine is not custom, but it does not look original but is still from the same type and year i would assume by looking at it (below '95, throttle body not multi port).
The way you find out which way your engine is running is from the driver’s seat, and it is running opposite from how the water pump is spinning, and they only make one pump for this truck: counterclockwise. It rotates the same as the new one, which is probably why when I bought the truck it did not have a thermostat installed. And the pulleys are newer, but they are rotating the right direction, excluding the alternator, it is also running backward(cooling fins are not going forward).
From what you’ve said it sounds to me like someone has altered the pulleys and the belt path. This is apparently making the water pump and probably the alternator both run backwards. Does the alternator charge correctly? It probably still would charge ok, but I wouldn’t be much surprised if it ran pretty hot too.
From the diagrams I can find on google, the water pump should be rotating the same direction as the crankshaft. Does this engine have a serpentine belt? The diagrams I’ve seen show it should NOT have a serpentine belt, but rather should have conventional v-belts.
Look under the hood for a belt routing diagram. I’m betting that someone has changed this thing to use a serpentine belt, but that makes the water pump run in the wrong direction, and that’s your whole problem.
Gotta be a bad thermostat . . . you can get one (or even two) bad right from the box. I’d check for proper temp range and then buy another . . . then do the “old fashioned” check . . . put it in boiling water with a cooking thermometer, watch to see when it opens/closes. When you say “always cold when it should be searing hot” , do you mean it’s cold even when the new thermostat is installed? . . . Rocketman
Regardless if the thermostat is open, or closed it is important that coolant flow is always maintained through the engine, and across the thermostat.
If the coolant temperature is below the thermostat open temperature the coolant gets bypassed directly back into the water pump, bypassing the radiator. My guess is this bypass has been some how removed, or not functioning, causing no flow with a closed thermostat. Not being familiar with the bypass setup on this vehicle I suggest getting a coolant flow diagram, and confirm the stock bypass setup.
the intake gaskets are on backwards,blocking the flow.
thats it folks.
I thought that might be it too, METOO2, but can’t get over the thermostat issue. So why does it run cold . . . not cool . . . when the thermostat is removed? Isn’t the flow still blocked? I’m betting on the thermostat. Rocketman
How are you determining that the engine is overheating? Your method of determining overheating may not be valid. Also, your dash temperature gauge may not be accurate.
I know that this pictures a 1.9L engine; http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528003d5ce ; but, if the hoses to the water pump, and the engine block, are the same size, they could have been switched
I bench tested this 160 thermostat in boiling water twice, and it worked. And when i say that i meant that it is cold (the end of the hose) when the thermostat is in but the engine runs TOO cold to see how the hose is without it, because the engine is running at less than 100 degrees.
I don’t know, I don’t think it is but i have gotten 3 bad in a row (all factory equipment 195’s) but the problem just seems to be it either doesn’t open or doesn’t have enough pressure to make it through the thermostat opening and into the radiator (hence overheating). The cold is also a problem because when the engine runs cold i get no heat (I live in high country) and it HORRIBLE millage.
The oil gauge does not work (at least I hope not, always bounces around, I think it’s the sending unit), but the temperature gauge does work. When it gets hot, steam comes out and everything in the engine is SEARING hot. When I say overheating, I mean it goes 260+, which is critical and could crack the block. And I have worked on a few vehicles in my life and I can tell when something is overheating.
Yes, steam coming from an engine could indicate a bit of excessive heat.
It seems that the coolant may not be circulating through the engine. Have you put a garden hose into the engine (not, the radiator) coolant intake, turned it on, and watched the water gush out the engine coolant outlet?