2004 5.7 thermostat pin up or down?

[EdGs]

Hello all,

Helping my nephew install a new water pump on his 2004 1500 with the Magnum Hemi 5.7. We noticed that the pin on the thermostat was down in the housing. I believe it should be up but looking for you guys to answer the question for me.



I told him that the heater cores can plug up on these he said his heat does not work and that he can hear gurgling in the dash. Wonder if this is part of the problem.

Thanks in advance.

 

[Dean2]

Can't quite tell from you picture but here is the proper orientation on the water pump. No heat, back flush the heater core.

Heater Core - HeaterTreater

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Heater Core Flush Procedure​

Dodge RAM heater core issues.

We see common issues with a temperature differential between the driver and passenger sides of the RAM truck, or lack of heat on both sides. The root cause of the problem is that the heater core is a parallel flow core, meaning the the water comes into the top and down multiple channels to the bottom. Most cores are serpentine flow and you’ll get equal pressure and flow across the entire core. You can check the flow of the heater core by letting the truck get to operating temperature with the heater off. When you cut the heater on, if you get a burst of warm air and then it dissipates, this is a strong indication of the heater core not providing heat as fast as the fan is extracting it.




The core is the narrowest constriction in the flow path and will act almost like a filter for any gunk in the radiator system. Dodge recommends routine radiator flushes, but no one pays attention and does this. If you are as negligent as us, this could be a cause of the problem. We also see issues when any work is done on the radiator system. Just replacing components or wiggling heater hoses can product particulates. You should always do a radiator flush anytime work is done on the coolant system.




The pressure is not equal across all the parallel channels and the back half will tend to “catch” the gunk and you’ll get a temperature gradient across the core which shows up as different temperature for the passenger and driver. It will get progressively worse and you can get to a point where you don’t have good heat on either side. Even with minimal flow the two heater hoses will get hot and you can’t really gauge the heat in the core by feeling the two hoses on a hot engine. What you have to do is cut the heat/fan on full blast and feel the two hoses from a cold start. The hoses should warm up at the same rate and get uncomfortably hot in a few minutes. This is a common problem and just doing a good flush on the core is probably not a bad idea if you have any concerns with temperature.




Here’s what we recommend to get the core flushed correctly. Since the flow is parallel, if you just get a few channels open, you’ll get good flow through the core. You can’t put enough pressure on the core to clear all channels once a few are open. To get to all the channels, you have to attack the problem chemically.
1. Isolate the core by either removing the heater hoses or just buy two brass garden hose repair kits at Home Depot and cut the hoses.
2. Flush the core backwards and forwards with a garden hose.
3. Fill the heater core with Prestone radiator flush and let it sit a couple of hours or overnight. We recommend the Prestone liquid flush because it works. We met the Prestone VP of engineering at SEMA a couple of years ago and he agreed with our analysis and solution. He said he would take our information back to their lab and look into a kit for just this issue, but I haven’t seen anything come of it.
4. Flush the chemicals out.
5. The trick is to swap the heater hoses such that the core will flow “backwards” when you reconnect.
6. If there is still gunk floating around in the radiator, the problem will occur again. We’d suggest just connecting the two heater hoses together and do a good flush on the radiator independent of the heater core.
7. Going forward it’s a good idea to do a flush every 12-18 months and swapping the hoses back each time.
8. If this helps, but not enough. It’s like the old High School Joke: “It’s a long way to the cafeteria, you have to flush twice…”




If this doesn’t help, the next concern is the blend doors and our replacement is a complete fix for any door issues. This is about a thousand dollars worth of free advice and we’d appreciate you keeping us in mind when you do see door issues.

 

[EdGs]

Thanks.

Does the pin on the thermostat go on top or bottom. As you can see. the original was down, which I believe is wrong.

 

[Dean2]

Did you even look at the picture I posted? Pretty clear which way the pin faces. With your picture I can't tell whether you are holding the thermostat housing or the water pump, so up or down is relative. If that is the thermostat housing the thermostat is in backwards, if it is the water pump, which is what it looks like based on the threads in the bolt holes, it is correct. The pin should face the direction of flow to the radiator, so up when sitting in the water pump, just like the picture I posted. If you double click the picture you can zoom right in.

 

[EdGs]

thermostat on his faces driver side, no bleeder screw.

Sorry, am out in the sun.

Your pic it looks like down. I was under the impression always to top.

PS his engine had been replaced at some point, not sure what it was from

 

[jawzs2]

The bleeder hole (jiggle valve) should be at the 12:00 position.

 

[HemiLonestar]

Bleed hole always up.

Did you even look at the picture I posted? Pretty clear which way the pin faces.

Don't get pissy, it's not that great a picture, especially if you don't have good eyes.

 

[Dean2]

Don't get pissy, it's not that great a picture, especially if you don't have good eyes.

Instead of busting my chops, after I have provided a great deal of very detailed information to the OP to try and help him out, how about if you actually post something relevant to the question at hand. If you have a better picture, knock yourself out.

 

[Dean2]

OP

Here is some more info re the Jiggle Pin. Comes from Gates. who make thermostats.

Thermostat replacement: jiggle pin and bleeder valve​

26/02/2021

Thermostat replacement: jiggle pin and bleeder valve​

A thermostat replacement causes air to enter the system, and getting rid of any remaining air pockets afterwards is extremely important. Read on to discover the consequences of insufficient bleeding, the function of the thermostat jiggle pin and its correct 12 o’clock position, and the tools to use with modern engines that have three different cooling systems.

The function of the thermostat​

A running engine should, at all times, be kept at the temperature that allows it to work most efficiently. In order to reach or maintain this specific operating temperature, and in order to avoid the temperature fluctuations that are very harmful to the engine, the system needs to be cooled. Therefore, the thermostat works continuously while the car is being driven, regulating the flow of coolant towards the radiator. It is very important to use the appropriate cooling water.
When it is time to replace the thermostat, you need to open the cooling system of the engine. This causes, on the one hand, some of the engine coolant to escape and, on the other, some air to enter the system. To get rid of these air pockets, the cooling system should be completely and carefully bled after the thermostat replacement. For modern engines with three different cooling systems, this requires special diagnostic test tools that may not be present in every mechanic’s shop, but that are nevertheless indispensable. If any air pockets remain, they are bound to interfere with the temperature sensor, so the wrong information ends up being sent to the dashboard, which can eventually result in engine overheating.

Thermostat jiggle valve and bleeder valve​

The thermostat jiggle pin is a pin that is located in the small hole in the plate valve of the thermostat and which should always be in 12 o’clock position during installation. It helps bleed the cooling system of trapped air by allowing air to pass into the radiator, after which it can be released from the system. The jiggle pin is a big help in bleeding air when filling an empty cooling system. The hole prevents the formation of an air lock when the valve is closed. Mind that these types of thermostats should therefore always be positioned so that the jiggle pin is located on the top side of the valve. After all, only this twelve o’clock position will allow trapped air to escape.
It should be noted that not all thermostats have a jiggle pin. Some thermostats have a bleeder valve instead, which is located either directly in the thermostat housing or in the coolant hose going to the heat exchanger or to the expansion tank.

 

[EdGs]

I really appreciate all the good info from all.

His heater core definately has an issue as there is no heat in the cab at all. To be continued...

Plus, after changing the water pump, the original did not look that bad, but there was corrosion and crud in the recess to the right of the impeller area, looking like it was not sealing in that area.

Additionally, he may have a leak where the driver side endcap is crimped to the radiator. So, one more thing to watch.