My 97 LX450 goes through the antifreeze in the overflow tank at an alarming rate. Basically the entire tank in roughly 30 miles! However, I have been checking the radiator and it is always full. I have leak tested the overflow bottle and it holds just fine. I don't see any evidence of a HG issue in the oil or anything else, plus the radiator is always full. No over heating or anything else. Any suggestions?
Coolant loss in overflow but not radiator? (1 Viewer)
- Thread starter NCLX450
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REKCUT
SILVER Star
When you say "goes through" do you mean that its at the proper fill line when you start the truck and it is empty after 30 miles?
How old is your radiator cap and is it OEM?
If the tank itself is not leaking (double check it)...then the coolant is being drawn out of it and you need to determine why that amount of fluid is being transferred.
The purpose of the over flow tank is to accept coolant from the radiator (this relieves pressure), then permit a certain amount of that coolant to return to the radiator when the radiator/engine cools sufficiently. Your radiator 'cap' is basically a two-way valve that operates at a specified 'pressure' (not temperature, though the two are related).
Check around the radiator opening (directly under the radiator cap) and look for signs of coolant leakage (dried coolant residue). If your radiator cap is defective and leaking it can allow coolant to spill at that spot, which can be hard to determine...because coolant evaporates quickly on top of the radiator or is moved about by the fan.
Just something to check.
If the tank itself is not leaking (double check it)...then the coolant is being drawn out of it and you need to determine why that amount of fluid is being transferred.
The purpose of the over flow tank is to accept coolant from the radiator (this relieves pressure), then permit a certain amount of that coolant to return to the radiator when the radiator/engine cools sufficiently. Your radiator 'cap' is basically a two-way valve that operates at a specified 'pressure' (not temperature, though the two are related).
Check around the radiator opening (directly under the radiator cap) and look for signs of coolant leakage (dried coolant residue). If your radiator cap is defective and leaking it can allow coolant to spill at that spot, which can be hard to determine...because coolant evaporates quickly on top of the radiator or is moved about by the fan.
Just something to check.
- Thread starter
- #4
I keep the overflow at the full mark mark and yes it's gone 30 miles later. The cap is newer and doesn't appear to leak. I have even checked around it a few minutes after driving around. Spring and seal appears to be strong on it. Thanks
inkpot
SILVER Star
I would do a pressure test on your entire cooling system. The coolant HAS to be going somewhere. You are either leaking it or burning it in the combustion chamber.
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If the bottle, hose and radiator cap isn't leaking, then something else is...
The idea of the overflow is as an expansion reservoir, the cooling system will suck coolant back into the system from the overflow during cool down. I would suggest that f you let the overflow run dry you will find that the level in the radiator will drop.
Time to inspect the obvious leak locations - i.e. every single hose clamp/junction in the system including heater system. Could even be the radiator seams (where the gaskets are for the plastic tanks to attach to the radiator core). Could be the heater cores etc. Lots of places the coolant travels in these vehicles.
Bit more info would help... when did this start, how long have you had the 80, what coolant are you running, last time it was changed etc etc.
cheers,
george.
The idea of the overflow is as an expansion reservoir, the cooling system will suck coolant back into the system from the overflow during cool down. I would suggest that f you let the overflow run dry you will find that the level in the radiator will drop.
Time to inspect the obvious leak locations - i.e. every single hose clamp/junction in the system including heater system. Could even be the radiator seams (where the gaskets are for the plastic tanks to attach to the radiator core). Could be the heater cores etc. Lots of places the coolant travels in these vehicles.
Bit more info would help... when did this start, how long have you had the 80, what coolant are you running, last time it was changed etc etc.
cheers,
george.
- Thread starter
- #7
I have had it for 4 months. Just regular old Prestone which I changed so it's nice a green. It's never over heated and the heater will burn you up. I just started checking the coolant and it did it before and after the change. I can try the cheap things first. Order a new cap. It will drop a little coolant under the motor that run over the transmission lines at near the engine block (driver side) but not a lot.
It won't be if you keep driving once the overflow's empty.
Is the coolant 'gone' as soon as you return (I.E. engine still warm and running)?
If you don't refill the over flow tank...does the radiator still remain 'full' after your next trip?
Sounds like you need to pressurize the system and look for leaks. Your radiator cap and over flow tank (IF working correctly) would simply be doing their jobs and all evidence would point to a leak someplace.
It's possible to have a coolant leak, the source of which in not easily found: (Rear heater tubes, Engine Oil Cooler, Head Gasket, PHH, Pin hole in hoses).
Until you find the leak...you might as well fill the over flow tank to the top...because it doesn't sound like you are having much (if any) coolant expanding INTO it.
Is your radiator cap OEM (or other)? Some of the cheap aftermarket caps don't work well for very long, if ever.
Dave 2000
Not all Land Rovers are useless!
Yup!
Sounds to me like PHH!
It's always interesting as you ask questions and dig into it.
Nope! It's not leaking a drop......except for the wet spot under the driver's side near the firewall. Other than that, it's dry!
inkpot
SILVER Star
OR the Throttle Body Coolant Line that runs under the intake manifold. Its also a big pain to change.
REKCUT
SILVER Star
What is different here is that it is sucking out the fluid when hot. I would think you have a leak in the coolant bottle. When you drive for thirty min then if anything it might push more into the bottle. I would think that normal leaks might leave bottle full but radiator with missing fluid.
This is a classic hose failure beginning.
Under pressure, the hose will allow a few drips out due to the pressure. As it cools, the vacuum cannot overcome the head pressure and the "blow-out" tear in the hose and it allows the radiator cap to open and draw fluid in from the reservoir tank. It will continue this cycle until the tear (hole) in the hose gets large enough that it will drip when shut off and starts to suck air in because the hole has opened up enough.
At this point, you will lose coolant faster, you will lose your heat, and MAY have a catastrophic PHH or TB hose failure.
You're driving a ticking time bomb from a cooling aspect.
Better get it checked out and man-up for the tough one.......
^^^^ Agreed. It is what has me puzzled as well and the reason for some of my questions.
A significant leak in the over flow tank should be easy to detect. A system that is pulling coolant from the over flow (at normal operating temps or just above) definitely has something wrong with it.
- Thread starter
- #17
I will get it checked out again. Actually had it looked at two weeks ago an was told it was the transmission lines leaking, which it's not. It's green around the transmission transmission line through the drivers side fender well. This is where the coolant drips.
inkpot
SILVER Star
I would guess that you just don't SEE that leak when the cooling system is at higher temperatures and pressures? If your driving down the road?
What is the age of your heater/ cooling system hoses?
