Some time ago when I was driving, white smoke came under the hood. Checked, and added coolant. Still the the temp gauge is above half way. Here is what I checked

1) Fuse seems OK
2) Relay seems OK
3) I jumped the fan with the battery and is running, so OK
4) I jumped the coolant temperature switch with a short wire and it is running when I switch on the engine. Does this mean this is faulty? Can you explain why the switch is faulty when it runs when jumped? Is it not suppose to run when jumped?
5) How do I Check if the Thermostat is working?
6) I saw some coolant splashed from the radiator and also steam coming out of the radiator (Not from cap). How do I check where exactly the leak in the Radiator?

Thanks for your help

 

If the radiator fan never runs when the engine is hot yet runs continuously when the a jumper wire is placed in the wire harness of the coolant temperature switch located in the thermostat housing, then the said switch is bad and needs to be replaced.

I am not sure from your information whether your radiator actually has a leak. If you are absolutely sure that the radiator is leaking, however, then replace the radiator and disregard the information below.

Don't worry about testing the thermostat. Just replace it because its pretty inexpensive. Likewise for the radiator cap, replace it with a new one. Before you install the new thermostat and radiator cap, top off the coolant in both the radiator and reservoir (when the engine is cool). Next bleed the cooling system. This is done by loosely installing the radiator cap, turning the dash heater ****/lever to fuel heat, starting the engine, and letting it idle until for approximately 15-20 minutes. Then turn the engine OFF and top off the coolant again in both the radiator and reservoir.

If the engine does not overheat during the bleeding procedure, then drive the car to see if the engine overheats or remains normal. Hopefully the latter occurs. If not, please let us know immediately. By the way, never let the engine temperature reach maximum HOT on the gauge.

 

Thanks Ron for your help; I Will do the test you have described
Also I just got the Coolant leak test pump kit from Autozone. I will test it to see if the radiator leaks

 

Good idea. Let us know how it goes.

 

Ron: I have a quick question:

When I bleed the system, should I have the coolant temperature switch jumped as I have it currently so that it always runs when i start the engine?

Thanks

 

If you fix the fan/switch before bleeding, then let the engine idle until the radiator fan turn ON three times during the bleeding procedure.

If the fan/switch is not fixed, then keep the connector jumped and let the fan run during the 15 minute bleeding procedure.

 

I purged the air for 20 minutes. The engine was ok; No overheating. So I took for a drive for 18 miles.

First 10 miles were OK. At the 10th mile, I stopped, opened the hood. Alas, Coolant has splashed every where. The next 8 miles the Temperature gauge started rising, probably because of loss of coolant? See pictures below. You will see coolant splashed everywhere

By the way I could not do pressure test because the the Cap was not fitting properly

Is my Radiator Leaking?

 

You really need to locate where coolant is lost from the system. For example, is coolant overflowing from the reservoir or spraying out from under the radiator cap, or leaking from a hose or the radiator, etc.

Is white smoke coming from the exhaust after the engine is warm?

Did you try replacing the cap and thermostat? If not, do this next. When done, the bleed procedure needs to be repeated.

 

Thanks; The coolant does not seems to be leaking from the cap or from the hose. I see steam coming out of a top of the Radiator where the fins meet the metal. Please see the video below. No white smoke from Exhaust. (Click on the picture to watch)

 

Though not definitive, it looks like the radiator itself has a leak. Are you able to post a picture showing precisely where the coolant seems to be spewing from?