Today i was driving to work nice cool morning out and noticed when i started to accelerate my car was heating up past 220 and at idle it would then cool down to 220 normaly it runs at 180 and sticks there. So i got to work let my car cool down for a few hours. Durning lunch i wnt to go and check it out i was thinking it might be a bad sending unit then i decided to pop my radiator cap and to my surprise it was empty i could basicly see down as far as i could see. So i checked around for any leaks didnt see any checked my oil looked perfect so i went to the store got antifreeze and put it in car runs at its normal 180 now but where could the coolant of gone i dont get any white smoke out the exhaust. For the longest time i would fill up my coolant tank and in about 2 months it would be empty so i knida gave up on filling it up i did neglect my cooling system last time i really checked my coolant was when i flushed the system about a year ago. But i would like to know were my coolant is going. Only thing i can think of is i have a small head gasket leak and it is buring when i am driving. If this is the case how will this effect my emissions since i have a test comming up in a month.

 

on the TBI V8 cars, the thermostat housing is alum. the intake is iron (or steel i forget)

the housing warps from the heat and time, and makes a TINY steam leak.


this leak slowly lets water out... and you generally wont notice until enough of it is out that the engine starts to overheat.



i would be looking for a similar steam leak in your car first... or get it pressure tested.

 

It is on my 91 V6 3.1 I think bouth surfaces are alumnium sp?

 

the cooling system isn't a completely sealed system, with no leaks it will still use coolant over time because of evaporation of the water out of the recovery bottle. the lower the coolant gets, the faster it will evaporate.
2 months is a long time to go without needing to add some water to top it off.
if the last time you filled the recovery bottle was last year, im suprised you haven't had an over heating problem sooner.

you don't need to top it off with a antifreeze/water mix every time it gets low, if you do, you wind up having too much antifreeze & not enough water in the system. use of a hydrometer to measure the coolant is recommended to keep it close to your preferred ratio.

 

Right now my ratio is way off because they did not have a 50/50 mix at napa and i needed coolant asap so i think im at 75 coolant 25 water i will just wait for it to go down again and add water but i am running at 180 now so i should be ok until i check it next.

 

there are alot of places that it can weep from slowly, heater core, even the water pump can let some past the bearing but, won't leak all the time (ask the quad 4 guys )

 

The manual I have says the total coolant capacity for my 89 TPI is 17 quarts so thats 4 gallons! I flushed the system with a kit installed in the heater hose and when it was done I let the radiator drain and closed it off. Afterwards I poured just a gallon of coolant in and it was full. I restarted the motor and was able to add another quart maybe. How do you guys get a 50/50 mixture in if the engine and heater are holding 3 gallons of water from the flush?

 

A couple of ways 1 = drain and add and like deen shaa says use a hydrometer until its where you want it. 2 use you flush tee and run it without the water intake for a while to let the water out careful not to over heat and add 50/50 till full. the only other way wich is way of the scale and unnecesary, but the only real way to totally relieve water from a block is to pop a freeze plug and put a new one in. but that is only for the real **** people LOL. very time consuming and really not necessary.

 

I forgot to put on this post that i found the problem i guess the past few tears i have had a crack in my radiator that only leaked when extreamly hot. I opened my hood to put washer fluid in and noriced something leaking to my surprise abour 1/3 of my radiaator was cracked going down replaced it have had no probelsms how ever it did not cure my overheating problem when i have my ac on.