98 V70 NA 135K miles - missing coolant

[cuhfs]

Agree with erikv11 above, but since I am a chicken... I usually start low and go slow and see what happens. I found my last leak at 6 or7 lbs. You see, after I reinstalled my new rebuilt head on my 04 C70 I had a loose clamp at the T-stat but could not find source of antifreeze leak for the life of me because the leak went to the back of the engine (car was sloped back on jack stands as that was the first test start after new head). New head has 30+ miles driven on it all dry
Good luck

[erikv11]

Nice work on the head rebuild and thanks for the advice, don't even go to 10 you likely will not have to.

[cuhfs]

Thanks

[abscate]

2 cups per month is about 8 mL per day.

Dont pull on the loose thread of uncertainty when the fabric tapestry of life is working well.

Watch it, do weekly checks on car, and watch for changes. You have a seeping hose that you can put right when Jupiter, Florida aligns with Bruno Mars.

[obayha]

This is only meant in a positive way, but isn't this the daughters away at college's car? It has had problems with over heating before and you and I and the rest of the "car world" people may look at the fluid levels a little more, but she has a track record already. Meant this in the best way. .
I would want to find/fix problem and not have to worry about it being in trouble at school.
All kindness
Shane

[erikv11]

That's an elegant (!) analogy Steve (the tapestry) but i would hazard poorly matched to the situation. a car that consumes coolant is throwing a red flag. Unless you know why the flag has gone up I don't think I would say the vehicle is working well. And I don't think a pressure test is at all like pulling a loose thread. Unless you think changing the oil is similarly pulling a loose thread because who knows, you may accidentally rip a gigantic hole in the oil pan in the process. We are talking about a very simple, low risk test. For example I use a blood pressure cuff bulb to raise the pressure, there is zero risk of over pressurizing.

[1ezliving4ume]

Something that is a little different about the heater core on these cars, is that it has a drain. So, if its leaking a little it will drain out and not get the carpet wet. Might check that drain hose for moisture.

Never noticed a drain for the heater. The one for the A/C is in the way when you service the heater core, but didn't notice one for the heater. But I only had one '98 and they might be different.
Shane

Shane,
I'm pretty sure the a/c evaporator coil and the heater core are both in the same giant plastic box in the dash. That giant plastic box has a drain so, if the line for the heater core or the core itself was leaking it would drain out that hole in the bottom of the giant plastic box. Rich

[98v70dad]

The pressure check is at your own risk as you stated. How about the dye put into the coolant for color change if it has mixed with engine gases?
I have a one year old or less overflow bottle and the cap is about the same age. Cost of shipping and it's yours. Have a bottle of dye laying around I can pass your way if you want to try that also. Have the hook up for the pressure test I can loan you for the price of sending it back.
As you might be able to tell, I had a problem on my '98. Mine was all the above, plus it was a turbo, so it has those lines also.
Let me know if you need anything.
If you do the dye test and it comes out good, then a pressure test, low pressure, might not be a bad idea. Again your call.
Shane

Thanks for the offer of the tank and cap and other supplies. I really appreciate it but I think I may have solved my problem (maybe ... I'll watch it.). Perhaps someone else could benefit from your generosity.

[98v70dad]

This is only meant in a positive way, but isn't this the daughters away at college's car? It has had problems with over heating before and you and I and the rest of the "car world" people may look at the fluid levels a little more, but she has a track record already. Meant this in the best way. .
I would want to find/fix problem and not have to worry about it being in trouble at school.
All kindness
Shane

This was her car. Mine now. I drive it 100 miles every day. I can afford to buy a new car but I decided that I like driving the Volvo and will do so until it gives up. It old. I can park it anywhere without getting concerned about scratches. I can spill stuff in it and it's no big deal. When she drove the car I always overfilled everything because I knew it wouldn't get checked.

[98v70dad]

So I may have found my leak. I've been checking all the connections for leaks when the engine is Hot, after a 40 miles drive home in stop and go traffic. Everything under the hood is very thoroughly hot. I've been doing this for months and never found anything. Yesterday I decided to do something different. So I started the car in the parking lot at work, popped the hood and started looking for leaks and within seconds a big generous blob of coolant leaked out of the top connection on the radiator. When I looked more closely I could see streaks of white below that spot that I hadn't noticed previously. When I installed the new radiator I was careful not to overtighten the connections to the radiator because I was afraid of cracking the plastic. I cHecked the for leaks (HOT) and figured they were tight enough because I saw no leaks. Plastic has a much bigger Coefficent of expansion than the metal band clamp which means the plastic shrinks more when it's cold, so I think that connection is leaking when the coolant is cold and the leak stops when the coolant heats up. Worth noting ... Maybe obvious but I never thought about it