Coolant Leak but No Puddle

[JW]

My 1996 850R's coolant level goes down slowly and steadily but there is never a puddle in the garage underneath the car. I have to add probably a quart of coolant every couple of thousand miles.

Is this something I should be concerned about? What could be happening if there's no coolant collecting underneath the car when it's parked? Maybe it's leaking too slowly for it to collect? Does 50/50 anti-freeze/water mix evaporate such that if it leaks slowly enough onto the garage floor it evaporates before I see it? Or does it only leak when the car is running, moving, and coolant is flowing thru the system and that is why I never see any coolant collecting?

Thanks.

 

[James Sweet]

My 1996 850R's coolant level goes down slowly and steadily but there is never a puddle in the garage underneath the car. I have to add probably a quart of coolant every couple of thousand miles.

Is this something I should be concerned about? What could be happening if there's no coolant collecting underneath the car when it's parked? Maybe it's leaking too slowly for it to collect? Does 50/50 anti-freeze/water mix evaporate such that if it leaks slowly enough onto the garage floor it evaporates before I see it? Or does it only leak when the car is running, moving, and coolant is flowing thru the system and that is why I never see any coolant collecting?

Thanks.

It's likely leaking only when under pressure. Get an old coolant cap, drill a hole and put a tire valve in it. Pump it up with a hand pump to pressurize the cooling system with the engine cold and see where it drips.

 

[Vrparts]

My 1996 850R's coolant level goes down slowly and steadily but there is never a puddle in the garage underneath the car. I have to add probably a quart of coolant every couple of thousand miles.

Is this something I should be concerned about?

Check your Transmission. Is it over full?
The coolant can be leaking out through the trans cooler in the radiator.

What could be happening if
there's no coolant collecting underneath the car when it's parked? Maybe it's leaking too slowly for it to collect? Does 50/50 anti-freeze/water mix evaporate such that if it leaks slowly enough onto the garage floor it evaporates before I see it?

50/50 should leave residue

Al

Had
79 245 D,
81 240 D,
86 240 320,000mi and running fine when traded
94 944 Green 257,503 mi CRUNCH Parted out
Have
94 944 White 149,000 The New one
94 944 Maroon 135,000 mi

 

[JW]

It's likely leaking only when under pressure. Get an old coolant cap, drill a hole and put a tire valve in it. Pump it up with a hand pump to pressurize the cooling system with the engine cold and see where it drips.

That's an interesting idea but the system is still pressurized after I stop the engine for at least a few minutes, right?

 

[Duane Hoberg]

On the 200 series motors, there is a curved hose that allows flex between the motor and the heater entrance through the firewall. This hose likes to crack on the underside, spray only onto the hot block, evaporate leaving no trace and a constant need to refill coolant. The first time it was a bear to find, the second took seconds since I knew where to look.

Not having an 850 around to look at, is there a similar hose some where at the back which create a similar situation. Look for a whitish residue on the block and a wet feel on the underside of the hose. Do this on a cool motor.

Look at the tranny level,( although after a while adding more than a gallon of fluid would push the tranny fluid to a level that i probalby would dump it out the breather and you would be concerend about a tranny leak)

Also look at the exhaust pipe. Any whitish vapor "after" complete warm up? Look at other completly warmed up autos idling exhaust and compare it to yours. If yours is visible or denser than theirs, you may have a head gasket problem. A compression check would comfirm a head gasket problem with the exhaust visibilty test just something that points to a problem.

Duane

 

[Peter Milnes]

<snipped>

That's an interesting idea but the system is still pressurized after I stop the engine for at least a few minutes, right?

Assuming that your pressure cap is OK and don't forget you will be much less likely to see hot coolant leaking as it evaporates quite quickly.

Cheers, Peter.

 

[Jeff Lesperance]

No, probably you have a head gasket going bad. The coolant is being pulled into the combustion chambers and vaporized. If there is no leak in the car, from the heater core, then it has to be going somewhere. How is the engine performance? You are losing compression with this leak, so it should be a bit down from normal. Either that or the coolant is mixing with the oil. How is that level? Is it too high or foamy?

 

[Ole in LA]

I had the same thing with my 960. It was crossflowing to the tranny and fried it (shorted out the electronics).

 

[Ole in LA]

check tranny fluid for foam as well

No, probably you have a head gasket going bad. The coolant is being pulled into the combustion chambers and vaporized. If there is no leak in the car, from the heater core, then it has to be going somewhere. How is the engine performance? You are losing compression with this leak, so it should be a bit down from normal. Either that or the coolant is mixing with the oil. How is that level? Is it too high or foamy?

 

[JW]

Just changed oil this past weekend. Totally clean.

I will check tranny fluid before I drive it the next time.

Thanks.

 

[Dave Shannon]

My 1996 850R's coolant level goes down slowly and steadily but there is never a puddle in the garage underneath the car. I have to add probably a quart of coolant every couple of thousand miles.

Is this something I should be concerned about? What could be happening if there's no coolant collecting underneath the car when it's parked? Maybe it's leaking too slowly for it to collect? Does 50/50 anti-freeze/water mix evaporate such that if it leaks slowly enough onto the garage floor it evaporates before I see it? Or does it only leak when the car is running, moving, and coolant is flowing thru the system and that is why I never see any coolant collecting?

Thanks.

I had an interesting issue like this on an old 740 I had. The water pump would weep only while warming up/cooling down. When cold it wouldn't leak a drop (no pressure?) and when hot it was tight (expanding seal?) but while the car was cooling down one day I saw a couple of drips under it, sure enough the pump shaft was slowly leaking. Checked again hot and cold, nothing. Good luck Dave Shannon (Spring Valley CA) 1984 245DL 200K 1984 245Ti 190K 1988 240DL 190K 1992 745 Ti 170K '01 Jeep Sahara 15K www.volvo2.homestead.com

 

[Conrad Edwards]

I would think two things....
firstly you should have a green expansion tank cap..the older ones could lose the seal after a few years and a newer one was issued. secondly the heater matrix could have a small leak....does the car smell of antifreeze first thing?

 

[John Horner]

My 1996 850R's coolant level goes down slowly and steadily but there is never a puddle in the garage underneath the car. I have to add probably a quart of coolant every couple of thousand miles.

Is this something I should be concerned about? What could be happening if there's no coolant collecting underneath the car when it's parked? Maybe it's leaking too slowly for it to collect? Does 50/50 anti-freeze/water mix evaporate such that if it leaks slowly enough onto the garage floor it evaporates before I see it? Or does it only leak when the car is running, moving, and coolant is flowing thru the system and that is why I never see any coolant collecting?

I would get an oil analysis done ASAP on the motor oil to check for oil getting into the engine. $20 from http://www.blackstone-labs.com is well worth it just to make sure.

John

 

[harrington8800]

Well, I have had a leak ever so slightly through the heatercore and it has a drip tube going through the body right over the exhaust, this is where I would suggest you might consider, especially if the 850 is same set up as my 240 DL?? I am considering a quick fix bars leak cube! I don't need the aggravation of taking apart dash, heaterbox, took 12 hours of back breaking close quarters poor access to nearly every screw even with the seats out, steering wheel off too! And I did two of them (blower motors I mean) Could kick myself in the ass for not doing heater cores too!, I really don't believe that BARS leak, or any other additive crap is good for any engine or car other than frequent oil changes, grease jobs, lubricating caliper sliders, wheel aligning, waxing, polishing cleaning. I work in a local CTC store in autoparts department and do a lot of Service writing/advising for the Canadian Tire store as well. I get guys coming up to every shift asking what is the best fuel injection additive, or oil additive, hell I am supposed to bullshit my way through and tell some poor sap how is going to make his jalopy with 300,000 klms drive like a new car? What's with that? I take the approach every and some get offended that I will not stoop low enough as to recommend what I truly don't believe in, tell LIES about additives!/! give me a break?

Well enough said!

Dan in Toronto, Canada

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