Msee

My car had the dreaded white smoke from tailpipe issue. I replaced the AOS and let it run a little while,the smoke disappered and i decide to take it for a test drive. As soon as i turned the corner in my neighbourhood all i could see was white smoke in the background. I turned around and went back to my house turned the car off. After getting out of the car i would not believe it a long line of coolant and coolant gushing from the rear passenger wheel. popped the trunk and the coolant was ozzing out of the tank. Anyone have an idea what the problem would be? Thanks in advance.

Anker

Blown head gasket. Hope that isn't it.

Schnell Gelb

Let's try some diagnosis?
Did you replace the AOS or someone else?
If someone else, get them involved. Do nothing until they evaluate the car because you may screw things up even further.
The coolant overflow is by that wheel. So first check you didn't overfill coolant.Is the coolant level low?
Do you have 'milkshake' on the dipstick?
If you did not overfill , start it and let it idle. What happens to the coolant level after the cooling fan kicks on ?
Next stage is probably pulling plugs to check for signs of coolant ingress. Also the Heat X may have failed.Search for more on "Intermix".

Macster

Was the coolant coming from around the cap or someplace else?

Could just be you failed to get the cap on right. The cap wants to be clean -- I rinse the cap under hot tap water to remove any coolant residue -- and the threads and where it seats at the tank want to be clean too. The start the cap -- avoid crossing threading the cap! -- and then tighten it down. I can't tell you how tight to tighten it but it takes more course to get the cap down completely.

If the cap is on right and not leaking -- What's the part # of the cap? A part # ending in "02" or "04" is the newest cap and the one that should used -- then it is possible the tank has failed. They fail after a while. Most often it is along the mold seam at the bottom of the tank. At first this can only leak very rarely but if the engine is shut off with the coolant very hot -- with the radiator fans having just come on -- the heat load of the engine can raise the coolant temperature and pressure to the point the tank split gives way and the coolant can -- in my Boxster's case -- just gush out.

A head gasket failure is a possibility but a slim one. A very slim one. In factd I don't think there's been one reported head gasket failure. Most (all?) of the time what is assumed to be a head gasket problem is actually a crack in the head.

But more often than not the problem is not even a cracked head. These are relatively rare thank goodness. A bad cap or tank is much more common.

FLT951

Macster, I love your stuff. I'm determined to pin you down for lunch. So, lets get Jeff together and cook something up.

Msee

The coolant coming from around the cap then flowing underneath the car.

Msee

I replaced the AOS. The coolant overflow is by the cap. You can see the coolant spilling out of the cap of the coolant reservoir

Macster

You sure the cap is on correctly? Not cross threaded? Tightened down properly?

And the coolant level is not too high? The coolant needs room to expand. There are two lines on the tank a min and a max line. The coolant level -- when viewed cold -- wants to be between the 2 lines.

Msee

This is the cap I currently have. Do I need to replace it. You can also see the coolant on the driveway.

Msee

The cap is on the right way and the coolant level is right too

paulofto

The cap part number ends in 01 based on your picture. Get a new one ending in 04. These things don't last forever and can lose the ability to hold pressure so spring for a new one.

Msee

I already ordered online. Thanks for all your help guys. I appreciate it. Will be back with an update when I replace the cap.

Macster

Replace the cap. If it proves to be the cap that's the worst coolant cap I've ever seen.

To know my car's coolant cap was leaking I had to get the coolant hot then shut off the engine and put a tent of aluminum foil over the fluid access bay and then after some time check it and spotted condensed water.

I removed the floor of the bay and checked the coolant tank as best I could for leak sign and seeing none guessed -- rightly so as it turned out -- the cap was leaking.

Prior to this there was never any leak sign on the ground. The only real sign of a leak was the tank fluid level dropping to the point the warning light came on then after adding around a gallon of distilled water to bring the level back up to where it should be the level being down again in just a few weeks' time.

Byprodriver

Looks like the original cap