Thermostat issues.

[rsh4364]

I have replaced 3 thermostats in 5 weeks, they work fine for about a week, engine warms to 195 opens and cools then warms back up,after about a week they open up at 160 degrees, two were from advanced auto with black plastic hockey puck the other was all brass from autozone.All worked well for short term.Suggestions welcome.I verified Temps on crossover and water pump with a pyrometer.While driving at speed temp is 160 when running at 35mph cools to 140.I am running a grill cover also.I can also add, thermo not sticking open as tank style block heater warms block not radiator.

 

[tim292stro]

Sure you're not putting them in backwards? If so, they would just "flow" once pressure to overcome the spring was achieved.

side note, I thought the factory temp was 185F...

Pyrometer = IR thermometer. The type/color of surface you measure can affect readings, as can the distance of the measurement, and the quality/type of the IR thermometer - not the best method to read piping for internal process water temperatures (the pipes and pump are not 100% transparent to the heat of the water inside them). Measure on a flat black surface for best readings, preferably one which is made of thin metal out of an air flow (like a radiator tank).

 

[rsh4364]

Installed with plastic towards motor, they functioned well for a week, then failed. I would think the temperature sensor part would be towards motor. Maybe I'm wrong. Only used pyrometer to get rough idea. Advice welcome.

 

[Drock]

If I recall I don't think it's possible to install them backwards? Most thermostats won't fit in the housing backwards. And yes the long side, or spring side goes towards the engine. Also I think I remember there being a discussion on here that the store bought ones were commonly problematic for our trucks. I used an acdelco one and have had no problem with it for 20000.00 miles. I'll see if I can find the part number for you.... Here it is acdelco,... #132-55, it's a 190°

 

[cucvrus]

Rick I may be on a witch hunt here. But my Mule did the same thing and it was not a thermostat it was a head-gasket. This thermostat issue was the start of it. I ran it for 5 years with the problem and eventually it just gave out completely and in its finale I could see steam escaping out the left tail pipe and the sweet smell of antifreeze was present. At that point the driving was over. I parked it. I may be wrong but it is worth looking into. Get a cooling system pressure tester and see if it holds pressure. It should hold 15 PSI. On the Mule after the temperature fluctuations it went to having heat in the cab at highway speed and then getting cool when slowing in city traffic. It would pressurize the cooling system and spill the pressure over into the overflow bottle. I would just pour it back over every day before I started it and run it all day. I went out of state or local it did the same thing. Like I stated the final straw was coolant in the exhaust.I posted the pictures of the failed head gasket not to give you a scare but to explain why the coolant never reached the oil. It cost me about $500. do the job right. I pulled the engine to do it and replaced all the seals while I was at it. But most importantly was the $$$ spend on getting the heads checked. That was only $150. but well worth it. Good Luck. I hope this is not the case for you but it is something to consider. I find it hard to believe that you have that many thermostats failing. I use what ever brand i get where ever I get them and don't have this amount of problem with them. This is a standard cooling system just like every other old V8/V6/L6 engine. Pressure test or as you do compression test. I always opt for the pressure test. I never did a compression test on a 6.2 the need never arose. Good Luck.

 

[rsh4364]

Thanks Rick that's something I will check,I did a compression test and all was good.Just seems odd the thermostats all work well for a week or so then start opening at 160.Gonna try an acdelco unit next

 

[rsh4364]

Ordered a Delco 132-55 last weekend when home. (thanks Drock ),it will be waiting for me when I get home Friday. But in the mean time it's gonna be in the single digits for 3-4 mornings and while I like the tank style block heater if you don't have a good thermostat it's a waste. Do yourself a favor and install the freeze plug style.I'm also going to order a Stant 14429 and a gates 33924.I didn't spend the extra money on a tank style to let a faulty thermostat get the best of me. But I will also be adding the temro freeze plug style heater I have.

 

[tim292stro]

That (132-55/14077122) looks like the correct part - I'm guessing that you had a Stant or Motorcraft thermostat in there when they went bad...

I have seen anecdotes of the plastic backed thermostats failing open within a week search other forums over the last few days - sounds nearly epidemic.

 

[cucvrus]

You could always just drain the oil and coolant and take it in the house with you at night. I do remember some other ideas about kerosene heaters under the engine because no electric was available. Remember them kast winter. All solid ideas on the Russian front during WW2. The good old GM block heater has been a main stay block heater on every CUCV plow truck. Without failure of the element ever. The cord a few times. Have these thermostats had their fair day before you decide them guilty? Just asking I never seen the failure of so many of the same part on the same vehicle in such a short amount of time. I hope it is but I am doubtful.

 

[rsh4364]

I'm also at a loss on these thermostats from both autozone and advanced auto. 3 our of 4 worked for a week. Then failed. I can start the 1009 watch the coolant temperature go to160 then open and drop to 110.when they were new I could watch them climb to 195 then open

 

[rsh4364]

Sorry don't know what that black thing is in previous post

 

[cucvrus]

That is a lump of coal that is going into your Christmas stocking. Or it can be burnt as an engine block heater. the choice is yours. It somewhat resembles a transformer face on an angle. Or an oil spot on the ice and snow.

 

[rsh4364]

That is a lump of coal that is going into your Christmas stocking. Or it can be burnt as an engine block heater. the choice is yours. It somewhat resembles a transformer face on an angle. Or an oil spot on the ice and snow.

Sorry I'm used to using my desktop,, now that I am working out of town I'm on a tablet that does weird things.

 

[topgun217]

Rick, did you flush your system??????? Thats probably the issue your having. I just helped Cole's buddy with the exact same issue your having. Flush, flush again, then reverse the process and flush again. Its takes time to do but when you see all the crud come out you'll be amazed. Poor kid was in a hurry to get the flush done the first time and didnt flush his system long enough. Give me a call if you want

 

[rsh4364]

Thanks Pete I'm in Columbus and not sure if I will get home this weekend..