I have tried all ways. I get great heat from the vents. But after 10 to 12 mins my temps start to climb then the aux fan kicks on. The lower hose never gets hot. The radiator especially lower area stays cold.
Cheers John.

 

John,

Yes, it is the grey 180 degree OEM one, I'm not sure it is listed on the Lucky 8 website but if you call them they will know exactly what you mean and set you up with the right one.

If I recall it is about $70.

 

Thanks Dave. It was listed as low temp stat and it was grey.
Fingers crossed this takes care of it.
Happy Christmas
John.

 

Hi Dave
I replaced the thermostat with the grey one from lucky 8. It definitely fixed the initial overheating problem. I tested the new and the other cheaper one in a pot of water before fitting and I did have another bad one. Just goes to show how poor some of the thermostats are. The thing is the truck is getting hotter than I would like. After about 15 mins of idling and driving up and down the road it gets up to as high as 226. It did peak breifley to 230!! What should be my next checks to make?The aux fan does come on. I have no gurgling noise behind dash. Also heater is blowing nice and hot. I have no detectible water in the oil.
I have checked belt routing and I have a new water pump. I also fitted a new temp sensor (the one behind the AC pump). I'm not using the car until I get to the bottom of this. I want it reliable for my son.
Thanks John

 

Way back on Nov. 29 in the original reply on this thread chubbs878 said the radiator is "stuffed." Cooling systems aren't complicated. If the pump is pumping, the thermostat is opening, the system is bled properly, there are no leaks and the temps are high the only thing left is a clogged radiator.

 

Yes.. I think chubbs is right on that. It seems I had a few things going on all at once. I was very surprised to have so many bad t stats in a row? That is solved now with the proper grey one I just fitted. As you said the only thing left is a dodgy radiator. When I place my hand on it there are definite cold areas after running for 15 mins. mostly toward the passenger side (US)
Thanks everyone for your help on this. One more thing, would a bad reservoir cap cause problems such as these?


Cheers John.

 

Hi Guys.
Well the weather finally cleared up. I took the time to replace the radiator. Just to recap i have replaced. Water pump, thermostat (grey one), expansion tank and cap, and now radiator. It starts up fine and gradually over a period of 10 minutes gets to 215 and climbing. I have the ultra gauge as recommended. At that point i shut down. The thing is i use a infrared lazer pointer to check temps on various engine parts and hoses etc. Nothing reads higher than 180 to 190? I took a reading at the base of the temp sensor behind AC pump and it reads around 180. The engine dos not appear to be hot at all? The aux fan does kick on. I have replaced the temp sensor, but now I'm starting to think the sensor is bad. I bought it from Atlantic British. Is this a common occurrence or unusual? Any other ideas would be truly helpful. All the best John.

 

If you know for a fact the thermostat opens at its 180-deg rating then you probably have to do a combustion gas test on the coolant. If the temps are getting up over 200 in 10 mins from dead cold then you prob have exhaust gas in it. It takes 30-mins for the coolant in my truck to hit 180-deg. Ya that's right, there's no way the coolant can get up to temp that quickly. I would be testing the coolant next.

 

Are you 100% sure you've bled the system completely as per Rave?

Remember these engines were designed to run up to 220 degrees. I would not be afraid of it getting past 215 on a test basis especially if you may still have air in the system.

What you need to do is see if it plateaus out at 220ish or keeps climbing to the point that the idiot gauge on the dash climbs up. If that happens then yes shut it down. Otherwise this could just be indicating you have not bled out the air completely.

Recently I had to rebleed due to changing out the leaking throttle body heater gasket. Initially with air in the system I saw it creep up past 215 but it did quit climbing. Took me about 4 days of cold bleeding and adding coolant (to replace the air) to get ALL of the air out.

You would be surprised at how little air in the system it takes to raise your temps 10 degrees. in my case, it was less than a table spoon of coolant! I know this because I tried for the first time the technique of adding coolant through the bleed screw (while engine cold) Each morning I had to add less. Each day I watched the temps as I had a 13 mile half stop and go, half freeway drive each day.

By the 4th morning I opened the screw, heard a small bit of air escaping and had to add about a teaspoon of coolant, and that day the temps were completely back to normal. in my case 188 cruise, 197 hot idle.

 

Is that while running or just after shut down and comparing to the Ultragage reading? You may want to compare same reading when cold. Mine is just a few degrees lower than what my ScanGauge reads. It does sound like from you are saying it may be a temp indication issue.
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