So i have a 1997 Dodge Ram 1500 5.9 Magnum 4X4 and I just put a new thermostat because the old one was “stuck” open but it turns out the new one, which is the right temperature is not working right and its about 30 degrees out and the truck still only gets to 140 F on the dash and even the heater blows cold. What should be my next step?




On another not, the truck also bogs down to about 400 RPMs and sometimes dies when i put it into reverse or drive from the opposite gear position, the truck is an automatic and I’ve already changed the TPS sensor…

Can someone please help me out?

 

Sometimes, the gauges on these trucks aren't very accurate. Do you have a laser temperature gun? (here's an example - https://www.harborfreight.com/121-in...ter-63985.html)

If so, what is the temperature readings for the thermostat housing and the inlet and outlet heater hoses?

It's also not uncommon in getting a bad thermostat brand new out of the package. I used to purchase Stant Superstat thermostats to combat this issue, however, they were bought out by another company. Not sure who is making good quality thermostats these days..

The same can be said for your TPS. It's best to install an OEM MOPAR TPS to fix your idle issue. You may also want to check your Idle Air controller (IAC) as well. At a minimum, clean out the well on the throttle body behind where the IAC bolts to the back of the throttle body, as they are infamous for carbon collection there.

 

You may want to drill a small hole in the t stat, It will allow air from getting trapped in(check out post #14 here). It's also possible depending on t stat and gasket used coolant is bypassing the t stat. Coolant flows around it between the stat and housing not allowing it to get up to temp.

 

So i got a new radiator cap and i still can’t get the truck up to temp but the top hose is hot but the hose on the bottom is semi warm, is that bad?

 

The radiator is doing it's job. Need to see what actual temps are though. You didn't install a safety stat by any chance did you?

 

In the future order a Calorstat from RA. However this is not necessarily the problem ATM. It's possible your dash gauge is incorrect and your heater core is clogged or your blend door is broken.

First determine if the engine is really topping out at 140F, then go from there.

 

I didnt install a safety stat, i installed the original 195ş t stat from autozone and im still getting a 140ş reading, could the temp sensor be bad and make it read 140 and it is actually normal?






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1997 5.9 magnum 4x4 1500

 

Should i clean my heater core and blend door or would it be better to clean it? I’ve never worked on either of them before…





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1997 5.9 magnum 4x4 1500

 

If you have a 195 degree stat in there, and its only getting up to 140, the stat is not working, or the gauge is lying. There are two temp sensor on your truck, one for the gauge, one for the PCM. The gauge sensor is a one wire. PCM is two. What needs to happen first is, what is the ACTUAL temp the engine is getting to? Either a temp gun, to read directly from the thermostat housing, or a scanner to check what temp the PCM is seeing.

 

If you don't already have one, please pick up a laser temperature gun (example of one is here - https://www.harborfreight.com/121-in...ter-63985.html).

Once you have a laser temperature gun and you have the truck's engine warmed up to operating temperature, point the gun at the thermostat housing to see what the temperature is. Also, point the gun at the two heater hoses to determine what the temperature is on both hoses.