Coolant Is Disappearing in HOTLNC

HOTLNC

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It's going somewhere. Last night on our way home, the warning buzzer sounded, but I did not see any message. I automatic checked the gages and found the temperature gauge above normal. While I started at it, the needle steadily fell until running normal at the bottom of the gauge. A few minutes later, we hear another beep and this time a "Low Coolant" message appears.

I pulled into a filling station and found the coolant bottle completely empty. I spent 75 cents for the water to fill it up. 35 miles and an hour (traffic) later, I put HOTLNC on the lift. There was no visible leaks. The coolant system was under pressure and the bottle was still full.

I replaced the water pump last month due to a leak, but I could see the coolant residue on the pulley bolts.

I checked all hoses (including the two PITA to replace hoses between the fire wall and the motor.)

There is no heater core leaks inside the car.

The hoses going to the thermostat and the motor/radiator are all new at the time of the water pump replacement.

The oil filter adapter is not leaking externally. If it mixed coolant with my oil that would be bad. I'll check the dip stick tonight.

The new coolant pump o-ring is not leaking.

Any suggestions?

If this was my truck, I'd be worried about a head gasket!
 
Could it be that you were simply low on coolant after your water pump change? Have you been running the engine and is it still full?
 
Could it be that you were simply low on coolant after your water pump change? Have you been running the engine and is it still full?

It takes awhile, but I've been loosing coolant. I check it every day or so. It has been slowly going down.

As for burping: When I changed the water pump, I did not drain the coolant. The coolant was brand new. So I pulled the WP and captured all of the coolant that came out. It was slightly more than 1 gallon. I put back a fresh gallon. No burping needed.

It's been running cool up until that glitch last night. If it was a belch, I'm glad it passed fast!

I forgot to mention, I can smell a coolant leak when I shut down the motor. The smell seems to be at the front of the motor. But I have not seen any leakage!
 
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although not too common on our motors it could be a head gasket....

Maybe take the plugs out and get a bore scope. If any of the pistons are REALLY clean it could be a sign that you do have a head gasket leak.
 
although not too common on our motors it could be a head gasket....

Maybe take the plugs out and get a bore scope. If any of the pistons are REALLY clean it could be a sign that you do have a head gasket leak.
That's really too scary to think too much about. If I could smell it only at the rear I would really have to think about a cracked head. But since I'm smelling coolant in the front, the leak has to be there.

I Hope.
 
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had a subaru that was losing coolant once...it turned out to ba a pin hole in a line..only way I could find it was to do a pressure test on the rad...any rad shop should be able to do it and for cheap
 
I second the pressure test. Any slow leak up front is difficult to find because it tends to evaporate quickly due to under-hood temperatures..

Have you checked under the car for leaks? Like drips or remnants of coolant (spots) in the driveway? Usually best to check after sitting overnight. You may find it on the K-member or sway bar.
 
I'd check the radiator and radiator tanks for leaks too.

They can leak where the tanks connect to the radiator.
 
I overflow bottle can also leak at it's seam...I had to change mine.

Yeah, I'm hoping it's something like that. The smell is strongest at that corner.

I'll check the overflow bottle and for pin hole leaks today or tomorrow. I have to fire up the propane heater -- It's 30 degrees in the garage!
 
Yeah, I'm hoping it's something like that. The smell is strongest at that corner.

I'll check the overflow bottle and for pin hole leaks today or tomorrow. I have to fire up the propane heater -- It's 30 degrees in the garage!

That just means it's 10 degrees warmer then in my garage... :p

Good luck... my 94 always seemed to loose a little coolant in the winter, I could never figure out from where, but you could smell it when the car was hot...

:D -J
 
OK, I found the leak. it was in the clamp area when the hose connects to the thermostat T from the overflow tank.

I was also surprised to see the intake hose (to motor from T) flattened for about 4 inches, due to loss of coolant and the suction from the water pump. A new hose should not do that! I'm replacing it also.

My truck has an internal wire 'spring' to prevent suction flattening -- I've never seen a flattened hose before; just knew the theory. I was able to make it return to normal by allowing air into the coolant system. That got me home.

I ordered both hoses from O'Reilly's.
 
OK, I found the leak. it was in the clamp area when the hose connects to the thermostat T from the overflow tank.

I was also surprised to see the intake hose (to motor from T) flattened for about 4 inches, due to loss of coolant and the suction from the water pump. A new hose should not do that! I'm replacing it also.

My truck has an internal wire 'spring' to prevent suction flattening -- I've never seen a flattened hose before; just knew the theory. I was able to make it return to normal by allowing air into the coolant system. That got me home.

I ordered both hoses from O'Reilly's.

An upstream clog or restriction can cause the hose to collapse also. You'll know for sure if the new hose collapses also.
 
Compression tester is cheaper than a bore-scope....

you mean a pressure test for coolant?, compression test would be done on each cylinder if its not running
i would also check the condition of each of the plastic radiator tanks, ive used baby powder to dust them before, kinda helps to highlight the leak area if there is one
 
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i would also check the condition of each of the plastic radiator tanks, ive used baby powder to dust them before, kinda helps to highlight the leak area if there is one

Good idea! Those are the hardest leaks to detect most times.
 
OK, I thought I fixed it. I found a bad gasket in the radiator cap. Coolant was pouring out, even while filling at the bypass tube. I replaced the cap with a Murray and refilled and burped.

I took the car out at highways speeds for about 20 miles or so. The gauge show normal temps. when I got back home, I checked for coolant levels and all was fine. I pronounced it fixed.

This morning, the wife and I took it to work. About 7 miles from home, going at 45 MPH, the needle started to raise. It hit top end and the computer told me to check coolant level. I turned it around and drove slowly while the motor cooled off. By the time I got back on the highway, it was back to normal temps. The computer kept telling me the overflow bottle was low. It stayed cool all the way home. The coolant bottle was empty. The only sign of coolant leakage is at the bottle.

We drove CREMPF to work. HOTLNC is back in the hospital bay.

If this is due to a bad head gasket, shouldn't there be bubbles in the coolant all the time?

All new hoses, except for lower T to motor and heater hoses. New radiator, thermostat and water pump. The motor runs great. My RX7 ran like crap when there was a water to compression chamber o-ring break. And it bubbled/blew coolant out the radiator constantly.

Am I in denial?
 
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