ssclone

So i just bought a 94 t/a with an automatic, and it has a new t-stat in it, new water pump, and the fans work.

my problem is it is using antifreeze and i would like to see wat you guys thought.

it does not smoke at all, or leak any coolant. but after i drive for about 30 minutes at a steady rpm (even 60mph at 2000 rpms), or run it hard usually WOT through 1st and 2nd, usually afterwards the coolant light comes on, and the rad is pretty much empty.

another thing is it does not miss. so im guessing i could rule out bad head gaskets.

when i bought it, it had a 160 stat in it, and it wouldnt build much heat. so i swapped a stock 180* in it, and it gets hotter, but doesnt blow hot air. i think the heater core could be clogged, just like the s10's and blazers do.
i also had a board member come over and he moved the stock fan settings from 226 to 185.

im just not sure what it could be. oil looks perfect, trans fluid is perfect. this thing has been giving me little troubles here and there, and im actually thinking about selling it so i can finish my chevelle.


thanks.


aaron

Jazsun

If you are truly losing an etire radiator everytime then you have a big problem, and I find it hard that you cannot figure out where it is going. Anyways its very possible for your car to use antifreeze and you will not see it out of the exhaust especially if its above 50 outside. Mine does it and you wouldnt ever be able to tell it uses antifreeze unless you checked hte dipstick. Runs like a champ. If there are no visible leaks and its not in your oil then you have a headgasket problem.

94_PatriotRed_Z

Do a pressure test on it, my car did this once it would only leak when driving. Even sitting at idle in a parking lot it would not leak, it was one of the plastic hose fittings at the bottom of the radiator that was leaking

ssclone

thanks guys.

yeah the exhaust doesnt smell sweet, and from what i can see, there is no visible leaks.
the oil is perfect, and the trans fluid is perfect.

im going to have to pressure test it to see where it is coming from.

it runs like a champ, and doesnt miss. but if you run it wot, for a short time, or cruise for a decent amount of time, it uses it.
but around town city driving with some short highway driving, it doesnt use a drop.


aaron

ssclone

did a pressure test on the cooling system,
found a few hoses leaking. fixed them.
still didnt fix anything.

did a compression test on the cylidners. all were from 100-120, but very consistant (also has 186k on it). no plug was really clean like it was burning coolant.

had a hose get a pin hole on me, and replaced it and a few other hoses, including the over flow tube, even cleaned and inspected metal over flow tube.

tried many different ways to bleeding the system of air. still no luck.

im lost here.

the only other thing i can think of is the cross over tube in the back has either a pin hole in it, or the o-rings are leaking.
i think the intake is leaking in the back, but im also wondering if its antifreeze that is also leaking there.
it takes about 40 miles before the low coolant light comes on, and sure enough, the rad is about 2 qts low.

other thig that is funny is, it does NOT pull any coolant from the over flow.
also my heat is not the best it could be. i think the heater core could be clogged. it is NOT leaking.

so how likely is it the cross over tube is effed up, or the o-rings are bad?


thanks.


aaron

NukeFPE

"other thig that is funny is, it does NOT pull any coolant from the over flow"....

Change the Radiator Cap ~ mine did this after I flushed it out last summer ~ the coolant will heat & flow into the overflow tank , but not return to radiator when cool ~ its the little spring loaded valve in the top of the cap~ The coolant should be going into the overflow tank ~ is yours over filled?

shoebox

You probably need to do a leakdown test. 100-120 on compression is not all that great.

The intake would have nothing to do with any coolant leak. There is no coolant running through it.

If coolant was getting into the combustion chambers, when you shut the engine down, pressure in the coolant system will go down very quickly. Therefore, there would be little chance that the system could pull any coolant back from remote reservoir. The system must be tight for this to happen.

You say your pressure testing did not fix anything. Do you mean it still would not hold pressure?

ssclone

yes it is also over filled. would that have an effect on anything?

thanks



aaron

ssclone

i know the intake does not have coolant flowing through it, but it leaks some oil, and i was thinking the oilw as mixing with possible bad o-rings on the cross over tube.

after it is shut down, it holds pressure.

it held 18psi for about 5 minutes before i took the pressure tester off. i was able to find a few hoses that leaked because of either loose clamps, or crappy ends.


thanks guys.

aaron

moparman

My car had a case of disappearing coolant. It would hold pressure when tested. Turned out to be a crack in the plastic radiator tank. Never saw a drop of coolant on the driveway. It would only leak when the car was at normal operating temp. See if you can find any cracks in the tank.

NukeFPE

Try a new radiator cap. Fill the system, bleed air out, put the new cap on & see what happens. The overflow can hold extra ~ if it overfills it just vents out the top ~ make sure the overflow line is clear & does not have any leaks ~ I've seen the aluminum tube in the battery tray become pitted through due to battery acid leaks.

ssclone

update.

i just finished replacing the head gaskets.
definatly was blown out between the bolt hole and water jacket on the number 7 cylinder.
what a job it was. but its finally done. just need t fix the exhaust leak, and its good to drive!..


thanks guys.


aaron