Strange coolant leak '87 760 GLE

Hi all,

1987 Volvo 760 GLE B280F

Well, I have a strange coolant leak. I can't trace it exactly, I just ran the car through
a car wash and draining from the rocker panel on the driver's side (LHD) was quite an
amount of coolant dripping from the drain holes!! Obviously, I have a leak in my system,
and it is travelling backwards through the frame. Since the rocker drain holes are higher
up than the floor pan, it can't be the heater core leaking from inside the car. I can't
smell coolant inside the car, but you can certainly smell it (lightly) from under the hood
when the engine is hot.

I can't really see where it is coming from, the rad looks fine, the hoses dry, the hoses
leading up to the heater core are fine (I also discovered that someone disconnected the
heater temp switch for my climate control, there is a sensor inline with the heater hose,
they just grounded the lead -which I assume senses coolant temp so the fan doesn't come on
until the coolant is warm enough for hot air to come out, I'm sure that is what the wire
is for, the other side is connected to the block. The tab must have broken off the sensor
(ground tab)).

Anyhow, yeah, weird..... maybe the bottom of the rad is leaking where I can't really see
it and leaking into the frame rails. Not a good thing.

where to look? The rad is original, so is the thermostat and all the hoses!! It just
appears to be dry, I had it on the hoist the other week, and no signs of leaking! arghh.
(looking is real hard for me right now, still recovering from a broken left leg, luckily,
the car is an automatic!)

 

Because there's more to the internet than hits alone, Myron Samila
wrote:

Can you clarify what you mean by 'rocker panel' (for those of us on
the East Bank of the Atlantic)? Are you sure what you saw was coolant,
and not water from the car wash draining out of one the various
enclosed drain tubes? Is the coolant level dropping?
--

Stewart Hargrave

Never wear a hat that has more character than you - Utah Philips


For email, replace 'SpamOnlyToHere' with my name

 

Hi Stewart,

Rocker Panel (U.S.) = Sill Panel (beneath doors).

As Les commented in an earlier thread, quoting Winston Churchill, "The UK
and the US are two countries separated by a common language."

Andy I.

 

Hi Stewart,

The rocker panel is the panel just under the door, continues rearward of the front wheel
to forward of the rear wheel.
_____
__/ |__
=O------O=
/\ where most of the leak came from..

my ASCII Volvo 760 LOL!!!

I think they probably used that exact system to design the "brick". Anyhow, it was
certainly coolant. and where the ----- mark is, that is where it was leaking from!!
(there are drain holes located in the rockers). And yes, it does drop in coolant level,
and you can smell it from the engine bay only, not the interior (the heater core seems ok
at this point).

At first I thought they washed my car with coolant!! (being green and all, bright green
and clean, just like what is in my resevoir).

 

Myron

This has got me baffled, to my knowledge (740 gle), the nearest point of the
car with any coolant in it (assuming V6) is the expansion bottle, but, even
so, there is no connection between there, and the void which those drain
holes connect to, on the straight 4 engine, the nearest coolant is either
the engine, or a small valve to the rear of the engine, again neither of
which connect to that void, the chassis rail coming back from the engine
bay, attaches to the floor about the middle of the floor pan, no connection
to the sill, that water would follow to emerge from the drains.
I might stand to be corrected, but the only place around the firewall area
for coolant type water to emerge from is the heating systems condensate
drain, (not sure where that would be on a lefty), the result of a leaky core
would emerge here as well.
Water draining from a sill after a car wash is usually the result of water
going down the heaters air intakes below the windscreen, if you pour a load
of water down the slats below your windscreen, does that reproduce your
leak? Still doesn't answer the quandry why the coolant drops, seems
impossible, I can't even imagine cooling water spraying into that cavity,
the actual pipes to the heater go through the firewall, again, no connection
to the sill.
Are you absolutely sure it's coolant, and that it's coming from the drains,
i.e. if you block the drains with your fingers does it stop flowing, then
pour out even more, when you unblock them?

Best wishes,
Ken Phillips (UK)

Myron

This has got me baffled, to my knowledge (740 gle), the nearest point of the
car with any coolant in it (assuming V6) is the expansion bottle, but, even
so, there is no connection between there, and the void which those drain
holes connect to, on the straight 4 engine, the nearest coolant is either
the engine, or a small valve to the rear of the engine, again neither of
which connect to that void, the chassis rail coming back from the engine
bay, attaches to the floor about the middle of the floor pan, no connection
to the sill, that water would follow to emerge from the drains.
I might stand to be corrected, but the only place around the firewall area
for coolant type water to emerge from is the heating systems condensate
drain, (not sure where that would be on a lefty), the result of a leaky core
would emerge here as well.
Water draining from a sill after a car wash is usually the result of water
going down the heaters air intakes below the windscreen, if you pour a load
of water down the slats below your windscreen, does that reproduce your
leak? Still doesn't answer the quandry why the coolant drops, seems
impossible, I can't even imagine cooling water spraying into that cavity,
the actual pipes to the heater go through the firewall, again, no connection
to the sill.
Are you absolutely sure it's coolant, and that it's coming from the drains,
i.e. if you block the drains with your fingers does it stop flowing, then
pour out even more, when you unblock them?

Best wishes,
Ken Phillips (UK)

 

Thanks Ken!

Thanks for the reply.

Yes, I'm 100% sure it is coolant, since I race cars, I know how much of a banned substance
coolant is! (it is incredibly slippery if it leaks on the track, this is my street car,
although.... a Volvo 760GLE race car would be nice .

Anyhow, what is more than likely happening is the leak is somewhere up front, then
buffeting all the way rearwards with air flow. I had a tricky oil leak on my race car
that made it appear it was leaking from the cam box, it was leaking UP from the oil pan
due to wind/buffeting. So I'm sure the leak is somewhere up front.

LHD has the heater hose entry point near the middle more on the driver's side, the coolant
resevoir is on the RHS at least on the V-6. Everything looks really dry, and I can't see
where it is coming from (from inspecting up top, and underneath). If the heater core was
leaking, I'd certainly smell it inside the car, there is no scent of that "sweet" coolant.

The worst thing would be the PRV block having a nice crack in the wall and leaking into
the crossmember, and into the frame rails. BTW: the frame (unibody frame connector) is a
big open channel, it also changes direction and goes to the sills (rocker panel).

If the engine was cracked, then this car would HAVE to become a race car... . Fit a
nice 8pt roll cage, big brakes and a Ford 302 V-8 conversion, and let's see how long the
diff lasts.

I'll try filling the vent up top with water and see what pours out.

BTW: Another weird thing (not Volvo related), my friend has a Renault R5 Turbo 2, with 2
fuel leaks. We thought it was leaking at the pump, well, it was, but then another massive
leak.... from the tanks, which are inside the car, fuel would drip into the chassis, leak
towards the back right near the fuel pump, making us think the leak wasn't fixed the first
time!!! What a wicked car

 

and I can't see

I'm always amazed at the way that everything seems to be on oppsite sides in
right and left hand drive cars.

"sweet" coolant.

Couldn't really agree more, plus you'd have a sauna effect, steam emitted,
and fogging up windows, when you put the heating on,, this happened to me,
hilarious!!

If that does communicate with the rocker panels (sills), that might account
for the leak, but, for everywhere else to have no evidence of water (anti
freeze residue) is very mysterious, can you pressurise the coolant system,
with compressed air up to about 11psi, that should reveal any obscure leaks
on hoses, etc. About the only place I can think of where water could be
unobtrusively getting into the chassis, would be from the underside of the
lower rad pipe, beyond that consider me flummoxed.

Very nice! I had a silly thought like that myself the other day, after
watching a programme on TV, concerning a Rover V8, lovely sound, would like
it to be coming from my volvo

 

My 1981 240 GLT wagon, manual tranny, was driving me nuts a few years ago
with a mysterious coolant leak. I had dismantled every thing around the
engine, including heater hoses as I thought it might coming from there. Had
it towed into the shop. The mechanic had to remove the transmission and
replace a rusted out freeze plug at the back of the engine and inside the
bell housing. Never would have found that on my own---didn't even know a
freeze plug could have been located there.
Derek