I have a 1986 xj6 4.2. Today I noticed coolant leaking out of what appears to be an overflow tube that is behind the engine and under the passenger front seat area. Any ideas what causes this? Just started today. It's coming out pretty good.

do you mean water is soaking the interior of the car?

usually the drain tube is for water from the evaporator, you have to get a car on a lift to see it from under the car.

are you sure it is coolant or just water? If water, use a metal clothes hanger and carefully insert it in the tube to unclog it.

Ah the memories flood back.

Hi 86xj6,

When I was i kid, I remember my mother getting into the turns pretty well in our xj6 - hey the car handled well, OK!!

On a warm day, you would go around a corner and all of a sudden, absolute shock as icy cold water bathed your feet if you were sitting in the front passenger seat.

There are two drain pipes (one on each side of the transmission) which clog up with road dirt over time.

It is the condensed water from the climate control evaporator and as Jose rightly points out, if you don't keep the drain pipes clear, water will back up and eventually fill the front foot wells and rot them out.

Every time you have the xj6 on a hoist, you should carefully poke a straightened coat hanger up each pipe to make sure it is clear of debris

Cheers and here's to not so cold feet

Nigel

Thanks for the responses. I should have said its leaking under the car near the passenger area. I will try to get a video of what is going on.

But it is coolant not water leaking underneath the car.

High humidity!!!


We've had a couple of days of this plus some heat! Unusual around here in July !


So, I've run both window coolers more than usual. considerable fluid weep under each !


They are doing their job.


Carl

Here is a video. I started the car and let it run for 15-20 seconds then turned it off and this is what happens. It's coolant that appears to be coming out of a tube/hose. Maybe an overflow? Not sure why it would do this though.



Let me know if the video works.

Almost? If the line I see is coolant "p,,,,ing," away, it isn't good. leaking uder pressure.


A hole in a heater hose would do this.


Or worse, the heater matrix has sprung a leak, it is collecting in the pan intended for condensate and coming out the drain hose from that pan.


Isolate the heater matrix by clamping off or plugging the heater hoses. run again, see if it stops after clearing the matrix and pan out.


I'd suggest merely turning off the heat, but the heater valve might not be responding correctly, and as such mislead you.


Carl.

Hi 86xj6,

Yeah, as you suspect, that stream is coming out under pressure. Not condensed evaporator water.

Sprung a leak somewhere. If it is coming out of the drain tube, then heater matrix is looking sheepish, although, even then, I am surprised at the velocity of the stream.

Can't be water pump related, as that is on the front of the engine.

I assume you have checked any water hoses at rear of engine?

Does the stream stop when you shut the engine down?

Cheers,

Nigel

Though the vid was a bit jiggly it *does* look as though the coolant was coming out of the drain tube that is intended to drain a/c condensate. As others have suggested, it seems you're in for a heater matrix replacement. Not fun.

Hope I'm wrong.

Check the hoses and clamps at the firewall and rear of the engine.

Cheers
DD

Finally got around to checking it today. I took off the hose that goes to the heater control valve and plugged it. Ran the car and shut it off. No leaks what so ever. I guess it's the heater matrix unit then?

Also I took off ther Heater control valve and closed it by hand and I am still able to blow through it.