850 GLT Radiator Clogged?

Hi everyone-

About two and a half months ago, the radiator on my 1993 Volvo 850 GLT
(~122k miles) cracked badly in multiple places, leading me to limp home
~60 miles with frequent refills. Got it replaced, everything's been
dandy since...

Until Thursday night. While driving, the engine temperature shot up,
and upon pulling over, I found that the coolant tank was empty.

My diagnosis so far:

-No visible leaking coming from the radiator or any hoses while the car
is off or in idle at the start of a drive.
-The leaking seems to be coming from the cap of the coolant reservoir.
-After driving for a short while, the temperature will increase. When I
pull over, the pressure in the reservoir seems uncharacteristically
high for the length of time driven, and there's some leakage over the
top.

My guess is that one of the hoses is partially clogged or collapsed,
causing the pressure to build (thus the leakage) and circulation to
decrease (thus, the overheating). I'd think that a drain, flush, and
refill, along with a careful inspection would fix this.

I'm taking it back to the place that did my radiator tomorrow morning.
Does my reasoning on what's wrong seem to be correct?

Thanks,

Noah

 

I'm sorry to say that this kind of pressure buildup almost always points
to a head gasket problem.

--
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.)

 

Does this place specialize in Volvos? If not, go somewhere else that
does. You want a mechanic who works on these cars all the time, not
someone who is learning on yours.

John

 

I'm afraid I agree with Mike F; it sounds like head gasket failure. The
recent history of inadequate coolant is especially ominous. You can do a
"shadetree" test: starting with a cold engine, remove the pressure cap and
start the engine. Pinch off any overflow hose and place the palm of your
hand over the opening for five to ten seconds. If you feel a steady rise in
pressure or (worse) fluctuation in pressure there is a great likelihood the
head will have to come off for repair. A hydrocarbon test by a professional
shop will confirm.

Some people have been able to fix early failures with a sealant that goes in
the coolant, but I am leery of those.

Mike