98 V70 AWD Dissapearing Coolant

98 V70 AWD Dissapearing Coolant

I recently purchased a '98 V70 AWD and noticed that the coolant tank
was empty. Even after filling it, the level would still disappear
gradually until the tank was empty again. It seemed to be coming from
the cap, so I replaced the cap and the leak continued. Upon closer
inspection, the coolant expansion tank itself had cracked around the
top where the cap screws on, so I did a complete coolant flush, and
replaced the tank. I've had the system pressure tested to 15psi, and
there are no leaks from hoses or the rad. The fan relay has also been
replaced, and the fan comes on after several minutes of idling or if
the A/C is turned on.

Despite all of this, it seems that after a long trip of 600km or more,
the coolant tank will drain itself overnight. I'm driving from east
coast Canada to Los Angeles right now, and have just made it to Las
Vegas (about 4800km so far). Every morning (after 1100km the day
before) I would have to refill the coolant as the tank would be empty.
Aside from this, the temperature would stay constantly at the 3 o'clock
position. Today, about a mile from Vegas and 44 degrees celcius (the
hottest temperatures experienced yet), the temperature moved into the
red zone, and the lambda light turned on. I pulled the car off the
highway immediately and idled for 15 minutes with the heat at full
blast. Even so, after another mile or so the temperature would
gradually move up.

Any ideas on what could be causing this coolant loss, and what I could
do about it? What about the lamda light? I trust that despite the high
temperatures here in the desert, this overheating is still not normal.

 

i had the same problem in my 850 - had to replace the radiator the dealer
said it was a hairline crack where the metal radiator joins the plastic side
bits - ouch
hec

 

Check under the carpet in the front - if the heater core leaks that's
where the coolant ends up, and it's a real pain to clean up. Also, I've
seen coolant leaks that only occur when the coolant is hot - that's the
time to do the pressure check.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

My 945TG had a disappering coolant issue a while back, and it turned out to
he a small crack in the plastic radiator neck. Only sprayed cooland when hot
and under pressure, and most of it went out the bottom so little/no pooling
inside the engine compartment. I bought a new replacement and changed it
myself - quite an easy DIY task, and much cheaper than having someone else
do it.

NCMan