[TheOtherLeft]

Hiya gurus,

I have a small problem with my colling system.

I had an Adrad (natrad) radiator installed on my GV back in April this year due to a leak in my factory one. I also got my hoses replaced and the thermostat was deemed to be OK.

Since April I've had to add about 200ml of water as there seems to be a very small leak.

I've checked for dried coolant around the joins and couldn't find any. I've run the engine with the rad cap off and there were no bubbles and the coolant isn't milky. I changed the engine oil/filter a few months ago and it was fine too. There is no milky residue on the inside of the oil cap either.

I've just been back to Natrad and the guy said it was common for cold thermostats to cause coolant to overflow slightly and hence drain out of the overflow bottle.

Whilst this seems to make sense in theory as the thermostat is at the bottom of the system and hence will remain closed even though the coolant is heating up at the top of the block. Hence the increased volume of the hot coolant will go into the overflow bottle and has the potential to drain out slightly before the thermostat opens the system can circulate as per normal.

I've never experienced this issue before so wondering if the natrad guy was just trying to palm me off.

Could this be the case of the thermostat being on its way out?

Is adding 200ml of water every 7 months or so OK or a sign of a leak?

Thanks,
Ben

[Westie]

200 ml in my mind is nothing to worry about. You could try and place a extra bottle on the overflo outlet hose and catch any water that is being forced out. This will let you know where it is going and if nothing then it could be a very minor leak in the system/hoses.

[fordem]

For starters I suspect the guy hasn't a clue as to where the problem lies and is just handing you a line to get you off his back.

What is a "cold" thermostat? One that has a lower operating temperature? One that hasn't reached opening temperature yet?

Don't let anybody tell you that the thermostat is in the "bottom of the system" or in the "return from the radiator" or "backwards" and remains closed even though the coolant is heating up - that is a clear sign that he/she is not familiar with the GV cooling system, which, admittedly is rather unconventional.

On a GV (2.0 or 2.5 engine) even though the thermostat is physically located in the radiator return, it does not depend on the temperature of the water in the return to open - the wax pellet on the back of thermostat is located in a loop which has a continuous flow of coolant (feel free to verify this for yourself - section 6B of the FSM - through the heater core and throttle body bypass), it will open even if the water in the return is cold.

[TheOtherLeft]

As I haven't found any bubbling in the coolant or oil in the coolant or water in the oil can I discount a head gasket issue? What other checks can I do at home to check for a cracked head gasket? I don't have a compression tester nor can I do a leak down test.

[atari4x4]

checked the o rings on the 2 coolant pipes that run to the back of the block on the exhaust side, i replaced the o ring on the main coolant pipe & there is the smaller on below the exhaust manifold. you might need a mirror or a periscope to suss it out.

http://www.auszookers.com/index.php?nam ... light=ring

[TheOtherLeft]

atari4x4 wrote:

checked the o rings on the 2 coolant pipes that run to the back of the block on the exhaust side, i replaced the o ring on the main coolant pipe & there is the smaller on below the exhaust manifold. you might need a mirror or a periscope to suss it out.

http://www.auszookers.com/index.php?nam ... light=ring

Bloody hell Atari, even in your pics I still can't see your leak. I see some white crusty residue but it's patchy around the other side of the o-ring from your red circled bits.

Finding my leak is going to be a nightmare.

Grrrrrr.

[atari4x4]

it wasn't really a leak, it would weep from the join, the dark areas in the circled part of this shot is moisture from coolant.



in this shot at the top of the join it's still dry & a grey colour.

[fordem]

TheOtherLeft wrote:

As I haven't found any bubbling in the coolant or oil in the coolant or water in the oil can I discount a head gasket issue? What other checks can I do at home to check for a cracked head gasket? I don't have a compression tester nor can I do a leak down test.

I'd say you're 99% safe - to be 100% there are test kits, I don't know if they are available in Australia, that allow you to test the coolant for the presence of hydrocarbons.

Here's one example.

[TheOtherLeft]

fordem wrote:

TheOtherLeft wrote:

As I haven't found any bubbling in the coolant or oil in the coolant or water in the oil can I discount a head gasket issue? What other checks can I do at home to check for a cracked head gasket? I don't have a compression tester nor can I do a leak down test.

I'd say you're 99% safe - to be 100% there are test kits, I don't know if they are available in Australia, that allow you to test the coolant for the presence of hydrocarbons.

Here's one example.

99% is good enough for me.

[royce]

unless this 200ml is enough to get the overflow to completely full and the engine is cold and the radiator full its not being lost out the overflow

while its not enough to call a problem, its worth making sure the small leak isnt going to be a suddenly big leak

[mattybish]

it would be worth getting the car hot and taking it to someone with a radiator pressure test kit, its amazing how obvious it becomes when you can pressurise the system and even small misting leaks show up easily

[TheOtherLeft]

Thanks for the pics Atari.

Comparing to Atari I think I've found the cause of the slight leak:


pics from the bottom. It looks like it's weeping to the right of the bracket.



pic from the top.

[atari4x4]

yep that would be it, it's the lowest point on that join.


Suzuki Part # 0928034005

D: 3.5, ID: 33.7 NONSTICK

[TheOtherLeft]

atari4x4 wrote:

checked the o rings on the 2 coolant pipes that run to the back of the block on the exhaust side, i replaced the o ring on the main coolant pipe & there is the smaller on below the exhaust manifold. you might need a mirror or a periscope to suss it out.

http://www.auszookers.com/index.php?nam ... light=ring

Just 2 bolts holding the coolant pipe eh? That ain't much.

Were there any surprises getting it off?

[atari4x4]

nah, i gave it a bit of a twist before pulling & it popped straight off. lube up the new o ring & slip it on.

[ajsr]

TheOtherLeft wrote:

As I haven't found any bubbling in the coolant or oil in the coolant or water in the oil can I discount a head gasket issue? What other checks can I do at home to check for a cracked head gasket? I don't have a compression tester nor can I do a leak down test.

pressure test the cooloing system

[TheOtherLeft]

atari4x4 wrote:

nah, i gave it a bit of a twist before pulling ... lube up & slip it on.

Never thought I'd hear that from a another man...again.