well here we go again.....replaced the thermostat, radiator cap and got a block tester to check for headgasket the test is showing that the head gasket is good no combustion in the coolant.... fan is working correctly... started the car let it idle for 45 minutes in driveway everything worked fine drove it for about 10 miles never got hot 164-173 got home and again coolant flowing out of overflow there is not water in the oil and the blocktester shows that there is no leaking or blown headgasket i am at a loss here can anyone help please......:-(
AAAAHHHHHHHHHHH!!!cooling problem 2nd post
- Thread starter drive805
- Start date
Yes, you need a new radiatior cap.
Make sure it's the correct PSI rating, I think 16 is the right one.
Do not use lower psi, higher psi in system = higher boiling point.
Do a flush and fill, careful to keep antifreeze/water to the right mix.
Clean the radiator of any debris.
HTH
Chris
Make sure it's the correct PSI rating, I think 16 is the right one.
Do not use lower psi, higher psi in system = higher boiling point.
Do a flush and fill, careful to keep antifreeze/water to the right mix.
Clean the radiator of any debris.
HTH
Chris
more info
its is a new cap and stat.... brand new rad and hoses the only thing not replaced was the heater valve when installed motor 3k on motor and trans rebuild.....first time it happened i changed the stat.... then second time the cap...now third time i changed the cap and stat......and still pushing water out the over flow still no over heating until the water is pushed out of the rad. no wate rin the oil and the block test says no blown head gasket
its is a new cap and stat.... brand new rad and hoses the only thing not replaced was the heater valve when installed motor 3k on motor and trans rebuild.....first time it happened i changed the stat.... then second time the cap...now third time i changed the cap and stat......and still pushing water out the over flow still no over heating until the water is pushed out of the rad. no wate rin the oil and the block test says no blown head gasket
- Joined
- May 26, 2001
Your symptoms and checks so far point to the most common overheating problem, radiator plugged. If it is an original core, that probably is the cause.
Turbo__Tim
One heck of a Tim!
- Joined
- May 25, 2001
Change the sending unit. It's lying to you. 
How old is the rad.?
How old is the rad.?- Joined
- May 26, 2001
Depends on how bad it is? At 30-40% plugged and 90-100 degrees, it will overheat. Just did one that was flowing ONLY 25% and this would be overheating anytime A/C was needed.
When the motor is turned off, heat is released from the engine internally, and the fluid gets hotter before it cools down. If it is lifting a 15 psi cap, internal temp must be over 250 degrees!
Average for a 15-16 year old original T-R radiator, rodded or not, that I have tested last couple years is 50%. Not enough for decent cooling! We have already had a couple 110 degree day this year and have seen the cooling problems already this year!
more info again
radiator was brand new (not rebuilt or recored or rotted out) with motor install 3k on motor etc...let it run for 45 minutes with the cap on and off at different times.....
not overheating..water being pushed out the overflow is 165-170 degrees
block test is a liquid that is poured into a container that sits on the radiator opening it is blue in color and if there is combustion gasses in the radiator the liquid will turn yellow got it at a local napa auto parts store
again everything is new in the cooling system except for the heater valve
thats radiator, hoses, thermostat cap,waterpump,
going to do a compression check tomorrow and see if there is a low cylinder or two then see what i can do from there
radiator was brand new (not rebuilt or recored or rotted out) with motor install 3k on motor etc...let it run for 45 minutes with the cap on and off at different times.....
not overheating..water being pushed out the overflow is 165-170 degrees
block test is a liquid that is poured into a container that sits on the radiator opening it is blue in color and if there is combustion gasses in the radiator the liquid will turn yellow got it at a local napa auto parts store
again everything is new in the cooling system except for the heater valve
thats radiator, hoses, thermostat cap,waterpump,
going to do a compression check tomorrow and see if there is a low cylinder or two then see what i can do from there
W
wawazat
Guest
Just an idea...
One thing to check may be the heater core. I've seen other cars (not GN's though) overheat and/or spew coolant out the recovery tank because of a plugged heater core.
Also, make sure your hoses and lines to and from the heater core are unobstructed internally.
The cooling system's capacity includes the heater core, so if you have filled the system with the correct amount of coolant, and the core is plugged, you will always have excess coolant in the system. Hope this helps.
One thing to check may be the heater core. I've seen other cars (not GN's though) overheat and/or spew coolant out the recovery tank because of a plugged heater core.
Also, make sure your hoses and lines to and from the heater core are unobstructed internally.
The cooling system's capacity includes the heater core, so if you have filled the system with the correct amount of coolant, and the core is plugged, you will always have excess coolant in the system. Hope this helps.
FWIW, I used the NAPA chemical tester and it fluid didn't change color either. BUT when my friend Steve used the emission sniffer over the open radiator it was clear that I had a blown head gasket.
After removing the heads you could see a very small trail where the gases were getting into the water jackets.
The engine builder had used the wrong HG. It was a FelPro but on stock 8 bolts heads it didn't crush the sealing rings properly.
The compression was 175# +/-5 on all six cylinders on this 600 mile rebuild.
The engine wouldn't overheat in light driving but with any aggressive driving it would cause the radiator water to go into the overflow. Then the temperature would climb rapidly to 230+.
Gary
After removing the heads you could see a very small trail where the gases were getting into the water jackets.
The engine builder had used the wrong HG. It was a FelPro but on stock 8 bolts heads it didn't crush the sealing rings properly.
The compression was 175# +/-5 on all six cylinders on this 600 mile rebuild.
The engine wouldn't overheat in light driving but with any aggressive driving it would cause the radiator water to go into the overflow. Then the temperature would climb rapidly to 230+.
Gary
T
TTA89
Guest
Are you running a Front Mount Intercooler?
- Joined
- May 28, 2001
RAD PROBLEMZ
Water, at a particular temp, occupies a finite space. Heat or cool that water and it will either expand or contract, requiring either more,[as in this case] or less space to contain it. Obviously, in this case we do not have enough space once the water gets hot, thus the need for the overflow tank. The problem is that the tank, assuming it's filled correctly when cold, is still NOT enough.
That being said:
1. I agree w/ Nick. The water temp IS NOT the thot to be 165 to 175* temp.
2. As others have said, the system has air pockets in it. That would not contribute to the water being blown out, as you said you ran the engine for some time when filling it, to allow the air to escape.
3. The heater has nothing to do w/ this problem.
4. I would do the following:
A. Compression AND leakdown tests. [WATCH the rad for bubbles when doing the leakdown!!]
B. Rad flow test.
C. Confirm that:
a. The belt tensioner travel is not locked and the WP is slipping.. Belt too long and the tensioner out of travel, etc, etc.
b. The stat is not in backwards.
c. The lower hose has the required coil wire in it to prevent it from being sucked shut.
d. The temp ga. is accurate. [I'd also scan the rad face when hot w/ an infra red gun to see if there are cold/hot spots]
Another way to confirm the gasket is/is not gone, is to pressurize the rad w/ the plugs out of the engine. After letting it sit for a while, unplug the ECM and open the TB wide open, spin the engine over w/ a clean paper towel at each plug hole... Look for H2O on the towels...
Also, "taste" the exhaust vapor Sugar? IT'S antifreeze!!!
Bottom line is: the volume of H2O is increasing due to heating and the system can't hold it..If it was air entrapment, it would seem to me that the air would rise to the top of the rad, [it's higher than the thermostat] and when the PSI got hi enough, [over cap setting] it would escape into the overflo, leaving the coolant behind.
My story, and I'm stickin to it!!
Water, at a particular temp, occupies a finite space. Heat or cool that water and it will either expand or contract, requiring either more,[as in this case] or less space to contain it. Obviously, in this case we do not have enough space once the water gets hot, thus the need for the overflow tank. The problem is that the tank, assuming it's filled correctly when cold, is still NOT enough.
That being said:
1. I agree w/ Nick. The water temp IS NOT the thot to be 165 to 175* temp.
2. As others have said, the system has air pockets in it. That would not contribute to the water being blown out, as you said you ran the engine for some time when filling it, to allow the air to escape.
3. The heater has nothing to do w/ this problem.
4. I would do the following:
A. Compression AND leakdown tests. [WATCH the rad for bubbles when doing the leakdown!!]
B. Rad flow test.
C. Confirm that:
a. The belt tensioner travel is not locked and the WP is slipping.. Belt too long and the tensioner out of travel, etc, etc.
b. The stat is not in backwards.
c. The lower hose has the required coil wire in it to prevent it from being sucked shut.
d. The temp ga. is accurate. [I'd also scan the rad face when hot w/ an infra red gun to see if there are cold/hot spots]
Another way to confirm the gasket is/is not gone, is to pressurize the rad w/ the plugs out of the engine. After letting it sit for a while, unplug the ECM and open the TB wide open, spin the engine over w/ a clean paper towel at each plug hole... Look for H2O on the towels...
Also, "taste" the exhaust vapor
Sugar? IT'S antifreeze!!! Bottom line is: the volume of H2O is increasing due to heating and the system can't hold it..If it was air entrapment, it would seem to me that the air would rise to the top of the rad, [it's higher than the thermostat] and when the PSI got hi enough, [over cap setting] it would escape into the overflo, leaving the coolant behind.
My story, and I'm stickin to it!!
Check to make sure that the jiggle valve on the radiator cap has a spring on it holding it closed. I made that mistake once. If the valve hangs down when you hold the radiator cap at eye level, you have the wrong cap. Pull on the valve a few times to see if it springs back.
Something to think about..........do you have the correct water pump for a TR? If I remember correctly, there is a waterpump for the NA 3.8L (V-belt) and a waterpump for the Turbo 3.8L (serpentine belt). I too have been experiencing minor problems with my cooling system since my engine freshening. Its very very consistant though. The car runs 175-182, and NEVER goes over 182, even on hot hot days. Rad was gone through last year and the rad hoses, heater core, waterpump, and thermostat are new. As of now, I plan on just replacing the thermostat, but may eventually put the original water pump back on. Because before the engine freshening, the car ran 162-165 no matter what. HTH, Im really wondering if Im right about the waterpump thing, because the thought has crossed my mind a few times on my GN (possibly got the NA pump).
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