Mystery?

[jzmd1]

After starting my 1997 Boxster yesterday morning, I drove several miles to a local supermarket. After shopping, we proceeded home. About 1 block from my house, the Check Engine light illuminated. No other warning lights appeared, the temperature gauge remained normal and I neither saw any smoke nor heard any unusual noises. After pulling into the garage and shutting the engine, I noted a large amount of a yellow-tinged, watery and slightly viscous liquid pouring from just inside the right rear wheel onto the garage floor.

The coolant level appeared normal and unchanged and neither the trunk carpet nor the area around the coolant cap appeared wet.

I had the car towed to a private and well respected local shop this morning. The shop owner called to inform me the Check Engine light reflected a failed oxygen sensor, however, he could not find the source of the fluid leak I described. He claimed the coolant level remained normal and could not detect a problem with the water pump or coolant hoses. He intended to search further.

Can anyone suggest the cause of this fluid leak or a course of action to determine the source.

Many thanks in advance for taking the time to answer.

[Loren]

Coolant is yellow/green in color - smells sweet and tastes really bad.

Coolant tank and/or cap failures are fairly common.

Bad oxygen sensor? Could be but I would ask him to read out all the P-codes and post them here.

[rcg412]

Coolant is yellow/green in color - smells sweet and tastes really bad.

Coolant tank and/or cap failures are fairly common.

Bad oxygen sensor? Could be but I would ask him to read out all the P-codes and post them here.

long shot - but was the a/c on, was it hot outside? could be condensation or water build up (was the fluid very viscous?)

[insite]

i have to disagree with you, Loren. i think coolant tastes pretty good.

retireddoc - it really does sound like coolant, especially since the overflow for the coolant reservoir is behind the right rear wheel. i think it could also be POSSIBLE for the coolant overflow tube to inadvertantly spray an oxygen sensor, causing it to fail. when my coolant overflow reservoir failed, lots of coolant wound up in my trunk. i popped a rubber plug in the trunk to drain out the coolant; it drained right onto an O2 sensor.

Edited March 21, 2006 by insite

[Tool Pants]

The hose for the coolant tank is where you saw the fluid. I would start by putting in the .01 cap if you do not have it.

There are 4 oxygen sensors. Which one is the problem one?

[pomocanthus]

The hose for the coolant tank is where you saw the fluid. I would start by putting in the .01 cap if you do not have it.

There are 4 oxygen sensors. Which one is the problem one?

ToolPants and Insite,

Where is the coolant tank overflow hose located? While performing AOS R&R, I noticed a dangling hose (not connected on one end) above and slightly forward of the passenger side pre-cat O2 sensor. This is while looking inside the rear passenger side wheel well. I traced that hose (by feel) back up to the trunk firewall and presumably passing through that firewall into the trunk where the coolant tank reservoir sits (passenger side of the trunk).

Is this the coolant tank overflow hose that you speak of? Should the open and dangling end be indeed open and dangling? Where should it be dangling? Its current location seems like it will dump coolant right onto the aforementioned O2 sensor.

Thanks for the help,

Hung

Edited December 31, 2007 by pomocanthus