coolant level drop in reservoir tank?? help!

[97tbird]

Hi all,

I have a 97 T-bird with the 4.6L sohc v-8.

during the past few colder months, I've noticed that the coolant level in my reservoir tank drops between half an inch to an inch below the "cold fill level" mark(on the reservoir tank) per about 1200 miles. (I check the level when motor was dead cold). I don't know weather this is normal or not.

Here are some facts which might help making your decision easier:

--low coolant light is not on.
--I can't see any coolant puddles/leakage anywhere.
--My oil level is normal, no oil usage.
--color of oil is normal(I think....)
--color of coolant also normal
--There are no symptoms of overheating, temp. gauge never goes above the middle,
BUT: I do notice that the car reaches normal operating temp. a lot quicker in the past months, although it's gotten COLDER outside.(this MAY be be due to the Arx engine cleaning I'm currently running in the engine),
--last time I had the coolant replaced (not power flushed) was about 7,000 miles ago.(thermostat was not changed)
--the motor has 90,000 miles.
--as I said, the drop in tank is: 1/2-1 inch/1200 miles.

What do you think is the cause for the drop?
where is the coolant going?
is it a leak that I can't see?
I'll be doing a UOA in a few months; would I be able to see what's happening..?

Would appreciate your comments/thoughts/help very much.
Thanks !

 

[oilrecovery2003]

I don't think there is a problem. Mine also does that. I think as long as it doesn't go from over the MAX to under the MIN and vice versa your alright. Im using Dex cool though.

I see they have a new antifreeze called Global antifreeze that is suppose to mix with all collant green red yellow orange whatever. Not sure about using that one yet Havent heard anyone talk about it yet.

 

[Spector]

One possibility is the head gasket. What happens is that in extreme cold weather, well, in my case below 20 degrees F, the head gasket has tiny cracks and the gasket contracts in the cold (okay if it sits 8 hours but 9-15 hours a definite drop in the level) and the coolant then passes into the combustion chamber where it is burned with the fuel. Thus, no leaks, no spills nothing not even the sweet smell or smoke of exhaust as the amount is so small. Even a UOA does not show it as the potssium levels and sodium levels many not move, boron may be up a slight amount but that is it. When warm weather, no change and a pressure test will not even reveal the problem, at least not in my case. So, that is my opinion as to what is happening. On mine, if i check the level one day and a cold night I will see it drop the next day.

 

[outrun]

I hate to over react but this would be a concern.

Bearing in mind one ATF cooler-Radiator leak cost my parents a Transmission and witness Dex-Cool dissolve my Intake manifold gasket.

A)Get a full leak down, system pressure test done

B)UV dye test is excellent

C)if nothing comes up, spend the $$ and have an ATF and engine oil analysis done to find any H20 contamination.

Just my advice, better this than 3,000$ for a new transmission & radiator or 800$ for new gasket install + and engine damage caused by dex-cool in the oil

food for thought hope you take it

 

[oilrecovery2003]

What is your reason for not likeing Dex cool.

It is a much better and stable coolant then the "Old green **** ". Less contaminants when I clean every year. Nothing under the cap etc. there has to be somthing you are blaming Dexcool on.

 

[AV8R]

The coolant loss is less than one might expect from a leaky head gasket-usually you know it when that happens, wet plugs, hard starting, etc. If hoses are good (and the clamps tight) take a look at the top tank of the radiator, usually plastic on that model. Cracks tend to develop near the inlet boss, where temperatures and mechanical stresses are highest. A hairline crack is hard to spot, but frequently causes intermittent, minor coolant loss. If that's the problem, a radiator shop can replace the tank.

 

[AV8R]

As a quick check for coolant leaking into a cylinder, pull the spark plugs and look for a really clean one, then shine a mag lite into the spark plug hole. If the piston top and cylinder are shiny-clean, that's where the leak is. If you are worried about water contamination in transmission or engine oil, make a little cup from aluminum foil and place a teaspoon of the oil in it. Heat the bottom of the foil cup until the oil smokes. If you hear rattly crackling noises, you have 1/10 % or more water in the sample. That's about 5ml of water in a gallon of oil.

 

[etech]

Something to check.

On my Jeep I was losing coolant. There were no noticable leaks or puddles. The problem turned out to be a clogged hose from the radiator to the coolant recovery tank. Apparantly it would suck coolant into the radiator tank but when pressured up and moving coolant to the recovery tank it would leak out of the hose fitting.

Cleaning out the hose solved the problem for me.

 

[wtd]

I was experiencing this on my 98 chevy truck with the 5.7L V-8. Coolant and oil looked normal and no external leakage. Two oil analysis's confirmed I had an internal coolant leak. It turned out to be my intake manifold leaking. One other sign I ended up getting that coolant was in the oil was that I was getting condensation buildup on the underside of the oil fill cap.

Just because your oil and oil level looks normal, doesn't mean you don't have an internal coolant leak. Do an oil analysis to see if coolant is getting into the engine.

Wayne

 

[widman]

Oil analisis! you may or may not show Glycol because it might burn off, but you should see sodium or whatever other minerals were in the water (unless you are using demineralized or distilled water). I was with someone this week who's analisis showed 4 consecutive months of increases in sodium (finally at 66 ppm) and magnesium (finally at 400 ppm) (the engine holds 1000 galons). This was parrallel to an increase in iron and copper over the 4 months. Turns out his water has a high macnesium content. We found a hairline crack in one of the heads. I suggested he get his oil analized by someone who did more than send a computer printout that said everything was within "norms".