Coolant Leak

[hkdolphins]

Low Coolant (tank almost empty) light on around 5 months ago, shop can't find and major leak. Replaced all OEM Main Radiator, Upper & Lower hoses. After drove 400 miles (in two months), found tank is only 1/3 left last night(no engine light). Any idea which part cause the leak(can't found any leak on the ground)?

thanks

[jmcS4]

Have you replaced the coolant reservoir? Over time they tend to crack and leak coolant

[hkdolphins]

Have you replaced the coolant reservoir? Over time they tend to crack and leak coolant

I didn't replace the reservoir, shop said it's look good.... I guess we have almost same car, did you one crack? thx

[jmcS4]

I didn't replace the reservoir, shop said it's look good.... I guess we have almost same car, did you one crack? thx

they often get spider web looking cracks in them. you could also look under the reservoir and look for dried coolant on the valve cover, it'll be white water spots.

[Brandywine050]

You may also want to try and get someone to put a coolant pressure tester on to see if you can source the leak before you spend any more money.

[badger.]

Mine is currently leaking from the rear coolant temp sensor buried between then firewall and motor. Fairly impossible to actually see it without removing some hoses and whatnot but I know it is from there because that little u-clip retainer got busted reinstalling the motor and it was ziptied. However I have a drip visible on the ground.

Impressive you can lose 1/3 tank in 400miles and not see anything on the ground. What does your oil look like?

[gcoy]

[QUOTE= What does your oil look like?[/QUOTE]

What I was thinking

[hkdolphins]

they often get spider web looking cracks in them. you could also look under the reservoir and look for dried coolant on the valve cover, it'll be white water spots.

It has some white sports over the valve cover, cleaned it up after the radiator work and didn't see anymore.

You may also want to try and get someone to put a coolant pressure tester on to see if you can source the leak before you spend any more money.

Shop did a pressure test before replacement and only found tiny leak on the top of the radiator passenger side ( the white spots over there), they said i can keep checking and add the coolant until it went bad. But I decided to replace it (also lower & upper hose, Serpentine Belt, tensioner, ATF flush), seem didn't fixed the whole issue.

Mine is currently leaking from the rear coolant temp sensor buried between then firewall and motor. Fairly impossible to actually see it without removing some hoses and whatnot but I know it is from there because that little u-clip retainer got busted reinstalling the motor and it was ziptied. However I have a drip visible on the ground.

Impressive you can lose 1/3 tank in 400miles and not see anything on the ground. What does your oil look like?

Right now, the coolant level is at middle of min and bottom, guess 2/3(of reservoir) coolant gone already. it's the Pink/Red Audi G13. I only drive it once a week and i didnt notice any leak on the ground. I feel like the coolant leak/gone while driving it (is it possible?) but ive no idea at all, i don't have much knowledge about cars.

Thanks

[badger.]

I feel like the coolant leak/gone while driving it (is it possible?) but ive no idea at all, i don't have much knowledge about cars.

Thanks

It is possible if your head gasket is leaking. Again, what does your oil look like? Look on the underside of the oil fill cap. And pull the dipstick out. It is chocolate milky looking at all?

Someone with more knowhow than me can chime in, but i think you can also consume coolant without a blown head gasket or without it getting in the oil but I'm not sure the possibility of that on this vehicle.

[hkdolphins]

It is possible if your head gasket is leaking. Again, what does your oil look like? Look on the underside of the oil fill cap. And pull the dipstick out. It is chocolate milky looking at all?

Someone with more knowhow than me can chime in, but i think you can also consume coolant without a blown head gasket or without it getting in the oil but I'm not sure the possibility of that on this vehicle.

Actually oil min light on when i was driving, then i found the coolant is low. I added 1qt Castrol Edge (oil change with Motul around 1K miles ago). Not sure the oil color now (may be its can show due the new oil just added). Will check it out tonight.

I found engine oil leak/burn more than before (i thought it can be min by VGC job done that i did 3K miles ago), will the head gasket leaking be a reason for increasing oil leak too?

thanks

[Brandywine050]

if the head gasket was blown at the crossover between the water jacket and oil drain back your coolant (once heated up and pressurized) could seep in the the oil drain from the head to the pan causing the oil to turn into a milky-white color. if it was blown between the cylinder and water jacket, cylinder pressure would pressurize your cooling system and it would escape the overflow.

[FulhamFTW]

Actually oil min light on when i was driving, then i found the coolant is low. I added 1qt Castrol Edge (oil change with Motul around 1K miles ago). Not sure the oil color now (may be its can show due the new oil just added). Will check it out tonight.

I found engine oil leak/burn more than before (i thought it can be min by VGC job done that i did 3K miles ago), will the head gasket leaking be a reason for increasing oil leak too?

thanks

Dude, if your oil light is coming on at the 1k mile mark, you definitely have bigger issues than leaking valve covers. I would look at the valley pan gasket and have your cylinders scoped for scoring.

[hkdolphins]

if the head gasket was blown at the crossover between the water jacket and oil drain back your coolant (once heated up and pressurized) could seep in the the oil drain from the head to the pan causing the oil to turn into a milky-white color. if it was blown between the cylinder and water jacket, cylinder pressure would pressurize your cooling system and it would escape the overflow.

The coolant escape overflow is at the reservoir, right? If there is no white water spot, that's mean it didnt overflow, correct? Shop found the oil pan leaking while replacing the radiation, they also repaired it last time. Will check the oil color later today.

If in case, the head gasket blown on either side, will it cause the engine oil leak/burn more than it was. It burns/leaks more than 1qt oil every 1K miles now.

[hkdolphins]

Checked, oil is not milky and also found some split around the oil filter area (the back of the engine), any idea?
thanks