Jump to content

Could Bad Thermostat Lead To Leaking?

Ty3upn3dn

Recommended Posts

Ty3upn3dn Enthusiast

Ty3upn3dn

Posted
Posted

If a thermostat is faulty and stuck open during startup, is there any way it could cause a coolant leak? This is on my girlfriend 1992 cherokee. I got under car during startup and once pressure built up in the system i could see coolant coming out fast down the lower radiator hose. I am leaning towards believing it is the water pump. Just wanted to check to see if the thermostat could cause it to leak if it was stuck open at startup, and then when engine got to operating temp if the thermostat began to work correctly the leak would stop. Thanks

Doug_Scott Senior Enthusiast

Doug_Scott

Posted
Posted
any escape should be thru the rad cap into the overflow tank. Maybe the rad hose is cracked or the clamp is bad or loose.

 

 

Not from a stuck thermostat. No connection to rad cap at all. Chances are the water pump seal is leaking when cold, but under pressure it stops leaking. You need to look at the vent hole behind the water pump pulley to see if it is wet or stained. Not much point in doing a pressure test, since it does not leak when under pressure, so just to a visual inspection of the vent hole.

One reason it can stop leaking when under pressure is if it has a lip type seal. Pressure will actually make it seal tighter. Generally water pumps have a ceramic seal though, and pressure will make them leak.

 

The thermostat does not directly control the pressure in the cooling system. It simply stops or restricts flow to the rad until a set temp is reached. Once open, it allows coolant to flow through the rad at an engineered rate (in other words the size of the opening is not just a random size, it is designed to make the coolant stay long enough in the rad to be cooled).

jblakeney Senior Enthusiast

jblakeney

Posted
Posted

Only thing I have ever seen a thermostat do is restrict flow or completely stop flow. Without it sometimes it is possible to make the heater core leak thou. Edgewise, NO it will not make any leaks.

 

Jbo

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • Grumpy Bear
      Transmission Temperature Hitting 220s

      By Grumpy Bear · Posted

      After I wrote that reply I went for a ride. 85 F out. So trans started at 85 F and it shifted the same as it did an hour latter at 168 F. I've never actually recorded the to cold to shift point but it is under 32 F before they start hanging on to a lower gear or leaving the converter unlocked. Both intended to heat fluid.    Yes, brake or bake. Absolutely.      Your welcome. True research ended decades ago. Field trials are still in play.    There is a thing called oxidation onset temperature. This is the heat related oxidation not the O2 exposure kind. For mineral oil that starts at 140 F. So what happens after 140 F? Each 20 F cuts fluid life in half! Does using a Full Synthetic improve that? Yes! By how much? Depends on the base oil type and a few other factors. But enough to notice. Some esters are even higher. There are even synergies between types the will raise it higher than any one component is alone.    Then there is "Hindered" oils. Antioxidant additives. Hindered Polyol Esters can sit at 500 F for years in a turbine.   When a blender brags his oil will 'take 500 F" in service he doesn't specify for how long. Water will dance on a 500 F hot plate for several seconds. @newdude put up a chart showing the relationship between fluid temperature and it's life in an automatic transmission. Here's a version of that chart for Group III based oils. These temperatures are those in the pan as observed as 'normal'. that is you drive as you do for as long as you do under what load you ask of it and whatever that temperature is this graph applies to. Flash temperatures of a few minutes isn't what his means.    Note that fluids held at a constant 240 F have a service life of only 20K miles. 220 F explains the factory exchange limit, eh? My equipment I keep under 180 F and I'm good if the cooler will hold it as low as 140 F. But that's me.   
    • Greg3160
      Actual Full Screen CarPlay on Refreshed Silverado/Sierras.

      By Greg3160 · Posted

      Im in the same boat. Carlink adapter comes tomorrow and dev account is in process. Would you he able to send the new instructions my way also? Question, do you have to change code and republish app everytime developer updates? Thanks for your assistance, truly the only thing i cant stand about my truck is the carplay limitation 
    • newdude
      2002 GMC Yukon

      By newdude · Posted

      Parts department or service department at the dealer.
    • Coastie05
      Future GMC Jimmy

      By Coastie05 · Posted

      I’ll take the blue one!
    • rav3
      Weight limit in bed

      By rav3 · Posted

      And Google AI says......... Yes, your truck can technically handle it, but you will be right at or near its maximum limit. A 2016 Chevrolet Silverado 1500 High Country with a 6.5-foot bed has a maximum payload capacity of approximately 1,770 pounds.Weight RealitiesLoad weight: Half a cord of dry hardwood weighs roughly 1,100 to 1,500 pounds depending on the wood type (like oak or hickory).Payload limit: Payload includes the weight of the wood, you, any passengers, and a full tank of gas.The math: If you weigh 200 pounds and have a full tank of gas, a 1,500-pound load of wood puts you right at that 1,770-pound ceiling.Safety TipsCheck the yellow and white sticker on your driver-side door jamb for your truck's exact payload number, as high-end luxury trims with extra features have slightly lower capacities than basic trucks.Expect the rear end to sag noticeably.Drive carefully, avoid sudden turns or stops, and keep speeds low if you have to travel a distance.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...