04' 996 TT coolant leaking after hard run
Discussion
Out for a very spirited run on Saturday. After parking up and turning the ignition off, i noticed steam rising out of the engine vents. Water was cascading under the passenger side rear bumper valance. This stopped after 2 mins. Approx. 0.75litres of coolant on the floor.
Had a chat with a very good local indy, said possibly a faulty coolant cap. So got one on order.
Took it out yesterday, for a gentle run to see if it was a one off, and low and behold, happened again.
After the x2 runs, approx. 1.5 litres of coolant lost. Then it just stops as it starts to cool or pressure drops.
The second time, i popped the bonnet and couldn't see any coolant leaking from the cap. The reservoir bottle itself looks in tact with no leaks/cracks. The water seems to be coming out lower down and then dripping onto the heat shields and bumper.
Temperature is not affected at all and no previous history of coolant loss.
Anybody had similar?
It's in with the indy now, so in safe hands for investigation.
Had a chat with a very good local indy, said possibly a faulty coolant cap. So got one on order.
Took it out yesterday, for a gentle run to see if it was a one off, and low and behold, happened again.
After the x2 runs, approx. 1.5 litres of coolant lost. Then it just stops as it starts to cool or pressure drops.
The second time, i popped the bonnet and couldn't see any coolant leaking from the cap. The reservoir bottle itself looks in tact with no leaks/cracks. The water seems to be coming out lower down and then dripping onto the heat shields and bumper.
Temperature is not affected at all and no previous history of coolant loss.
Anybody had similar?
It's in with the indy now, so in safe hands for investigation.
Edited by cinque on Monday 29th February 11:44
The expansion tank / header tanks are known for cracking. Once the colour of the tank begins to go yellow it's a good sign the material is becoming more brittle with age. You can sometimes see hair line cracks around the stiffening ribs on the tank walls.
As temps and pressures increase, any cracks are forced open. If your still on your original tank that would be one of the first places to look.
Caps do also leak, but your model year means you'll be on the revised cap design, so shouldn't be as much of a problem. A good old school check on the cap however is to wrap a sheet of kitchen roll around the cap and secure it in place. Take the car for a blast and any leakage from the cap will be shown up on the kitchen roll.
After the obvious points above your into looking for hose and fitting leaks.
Good luck
As temps and pressures increase, any cracks are forced open. If your still on your original tank that would be one of the first places to look.
Caps do also leak, but your model year means you'll be on the revised cap design, so shouldn't be as much of a problem. A good old school check on the cap however is to wrap a sheet of kitchen roll around the cap and secure it in place. Take the car for a blast and any leakage from the cap will be shown up on the kitchen roll.
After the obvious points above your into looking for hose and fitting leaks.
Good luck
Edited by Homer J on Monday 29th February 12:46
The other possibility is the water pump. Mine failed such that it leaked around the shaft, but only when the engine was hot and running. It's at the bottom left of the back of the engine, but you'd expect to see the coolant being thrown all over the place by the pulley if that was the source.
Pete
Pete
Homer J said:
The expansion tank / header tanks are known for cracking. Once the colour of the tank begins to go yellow it's a good sign the material is becoming more brittle with age. You can sometimes see hair line cracks around the stiffening ribs on the tank walls.
As temps and pressures increase, any cracks are forced open. If your still on your original tank that would be one of the first places to look.
Caps do also leak, but your model year means you'll be on the revised cap design, so shouldn't be as much of a problem. A good old school check on the cap however is to wrap a sheet of kitchen roll around the cap and secure it in place. Take the car for a blast and any leakage from the cap will be shown up on the kitchen roll.
After the obvious points above your into looking for hose and fitting leaks.
Good luck
this... My local Indy used a fiber optic camera to get underneath the expansion tank to see the traces of coolant. As temps and pressures increase, any cracks are forced open. If your still on your original tank that would be one of the first places to look.
Caps do also leak, but your model year means you'll be on the revised cap design, so shouldn't be as much of a problem. A good old school check on the cap however is to wrap a sheet of kitchen roll around the cap and secure it in place. Take the car for a blast and any leakage from the cap will be shown up on the kitchen roll.
After the obvious points above your into looking for hose and fitting leaks.
Good luck
Edited by Homer J on Monday 29th February 12:46
Reads like the coolant tank. Coolant gets hot, tank gets more pliable. Hot coolant equals more pressure and the tank opens up -- typically a crack/split on the bottom that coincides with the mold seam -- and one has coolant running out to the ground.
While a cap could leak, I've had to replace the one in my Boxster and Turbo, they generally leak just vapor. The tank level drops slowly over time.
The only time I've had the gushing hot coolant is from a coolant tank leaking in my Boxster.
I let it cool down over night then added nearly a gallon of distilled water the next morning and started the engine. No leaks. Drove the car a couple of miles to the dealer for a new tank and there was no leak sign even after the drive.
While a cap could leak, I've had to replace the one in my Boxster and Turbo, they generally leak just vapor. The tank level drops slowly over time.
The only time I've had the gushing hot coolant is from a coolant tank leaking in my Boxster.
I let it cool down over night then added nearly a gallon of distilled water the next morning and started the engine. No leaks. Drove the car a couple of miles to the dealer for a new tank and there was no leak sign even after the drive.
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