Ok yesterday had the temperature gauge go past the 3/4 mark. Later checked the reservoir and it was at full. Thought possibly faulty thermostat. Brought it into a mechanic , he said he pulled off the rad cap and it was down 3 liters singe topped it off and ran it for a test run and the gauge is sitting in the middle no overheating at all. He said it might of had air in the system.
I'm stumped
No coolant in oil and no white smoke. Why would it use up so much coolant and not pull from the reservoir ?

Please delete wrong forum

 

Ok yesterday had the temperature gauge go past the 3/4 mark. Later checked the reservoir and it was at full. Thought possibly faulty thermostat. Brought it into a mechanic , he said he pulled off the rad cap and it was down 3 liters singe topped it off and ran it for a test run and the gauge is sitting in the middle no overheating at all. He said it might of had air in the system.
I'm stumped
No coolant in oil and no white smoke. Why would it use up so much coolant and not pull from the reservoir.
It's a 2003 4.7

 

it could have had air in the system, and as the pressure built and the coolant expanded it pushed into the overflow, and while the truck was running the air bubble was ALSO pushed into the resevoir which would then suck a bunch of fluid back out into the system as it cooled down, when was the last time you checked the coolant, it DOES evaporate over time, also is the hose going from the system cap into the resevoir clogged (sounds like it might be if there was fluid in the overflow, but the system was low)

 

Thanks fir the reply.
I just Don't get why it didn't pull from the reservoir if it was low.
2 months ago as I was going to get a rotor put on
Hehe just before I. Got there the rad cap went and it leaked He topped it off at the rad cap. Afterwards I kept checking the reservoir to make sure it was okay which it was. But I was remembering last night when I was younger I use to top off the rad and run the heater and then it off further if needed it. I never thought of it much as with the reservoir tanks that if it did been coolant it would take it from there. I drove it later today and it is back to normal with the needle sitting dead center.
Again I thought isn't this the job of the reservoir to store excess coolant in case it is needed.

I just hope the little bit of overheating didn't mess anything up
Now if it gave a problem with the head gasket wouldn't there problems with constant white smoke?

Is there telltail signs if I did damage to the head gasket or block?

Thanks in advance.

 

if you didnt peg the temp gauge to the high side i wouldnt expect any damage, but i would definitely check the line going into the overflow from the coolant system.

 

I would burp the coolant system just in case. You can read the write-up on the DIY section on the first page.

 

my durango is doing the exact same thing .. my overflow is allways full.. but it gets low in the radiator.. now its doing it more often .. i have to add about a cup or 2 of coolant ever 2 or 3 days ... its not leaking and its not smoking...not coolant in oil and no oil in coolant...but it will start to overheat when i make the durango motor work harder than normal... i wonder if it has a head gasket leak blowing exaughst into coolant... if that would make the coolant low by burnning it up ???and also today when i got home from work my wife drove the durango this morning, and when i got home from work at 4pm i checked the coolant in it, when it was cold and i took the cap off and heard a vacume sound,, is this normal ???

 

Replace the hose between the reservoir and the cap as it is probably blocked or cracked. Replace your radiator cap as well.


yes on a cold motor there will be a vacuum but it should gain the mass from the overflow so but it sounds like it's not.

 

ok i got the durango tested today for exuaghst in the coolant... they said there is none but its not 100% for sure.. my coolant bubbles when i got the cap off and im looking at it.. and aLSO when i rev it up the coolant wants to come out instead of being sucked back down the radiator... he also tested my rad cap and said it only holds 15psi and it leaks air under pressure... i got a new rad cap today and a thermostat.. got the new cap on and going to do the thermostat in about an hour.... he said its getting air somehow... one guy told me a bad water pump would make it bubble... the durango olny overheats when i get on it hard for awhile and drive down the highway on hot days.. i know somthin is not right with it ...it gets hot a blows the coolant out the overflow

 

They are on ta something IMHO.


Replace the cap as it should be at about 20 psi so I would replace it with one like this:



CST/Radiator Cap Part #7720 from auto zone